Category Archives: habitat plots

Creating habitat for beneficial insects: We planted it. Did they come?

Woman wearing sunglasses and a baseball cap is emptying blue and yellow bowls filled with soapy water and dead insects into a deli cup.
Here I am collecting insects from our yellow and blue pan traps last September.

Hopefully you’ve been following along with a project I’m working on with Betsy Lamb and Brian Eshenaur to establish (and document the impacts of) habitat for natural enemies of pests and pollinators (collectively, beneficial insects). In December, I wrote about how the plants were growing, and in February I wrote about the time and money we’d invested in the project so far and the success of our weed management strategies. I promised an update on insect sampling, and here it is!

First of all, let me clarify that we were collecting more than just insects. Insects only have six legs. We also collected arachnids like spiders (and harvestmen), which usually have eight legs, and pillbugs, millipedes, and centipedes, which have many more than eight legs. All of these “bugs” could be correctly called arthropods. But there’s more! We also counted earthworms (which are annelids) and slugs and snails (which are mollusks). Hopefully the entomologists in my audience will pardon my use of the term “insect” to include creatures that crawl or fly but may have more (or less) than six legs throughout the rest of this post.

I described the ways that we collected insects in an earlier post. As a quick refresher:

  • Pan traps catch flying insects, especially those attracted to the colors yellow and blue.
  • Pitfall traps catch insects that crawl along the soil surface.
  • Sweep nets catch insects that are flying or hanging out on plants.
The left picture (pan traps) shows a yellow and a blue plastic bowl sitting amongst grass and weeds. Each contains a rock and is filled with soapy water. The middle picture (pitfall trap) shows a deli cup buried in the ground to its rim and filled with liquid. A clear plastic dinner plate is held above the deli cup by wire legs. The picture on the right (sweep net) shows a woman wearing a t-shirt, jeans and a baseball cap sweeping a large white canvas net just above the ground as she walks through a field.
Different methods used for sampling insect from our habitat plots included pan traps, pitfall traps, and a sweep net.

Below is a quick reminder of our treatments. You can read all the details here. Except for Treatment H. These are “new” plots that we added in 2019. I just measured out four, 23-foot long sections of grass planted between rows of Christmas trees in the middle of the field. These row middles are mowed by the excellent Field Research Unit staff at Cornell AgriTech, where our research field is located. The grass mixture was seeded right after the Christmas trees were planted in Spring 2018, but it does include some blooming weeds from time to time (dandelions and clover, especially).

Treatment Description
A Spring transplant, no mulch
B Spring transplant with mulch
C Spring direct seed
D Buckwheat cover crop, then fall transplant
E – control Whatever was growing there, just keep it mowed
F Soil solarization, then fall direct seed
G Herbicide and tillage, then fall direct seed
H – control Mow seeded orchard grass mix
Mowed grass between rows of small Christmas trees
Mowed grass between rows of Christmas trees in the middle of the field is a second control treatment for insect sampling.

And one last note before we get into the actual results. These are still preliminary results. Many, many thanks to Jason Dombroskie and Paige Muñiz for helping us with insect identification. Identification and number crunching of the data are still ongoing.

 

Ok, ready to see some cool insects (etc.)? Here we go!

 

Spiders and harvestmen

On the left, a harvestman with a plump body lacking distinct segments. In the middle, a spider with two distinct body segments. These two pictures were taken by David Cappaert, and are available on Bugwood.org. On the right, a black and yellow garden spider.
Spiders and harvestmen both have eight legs and are useful predators to have in a field or garden. The garden spider on the right was probably the largest arachnid I spotted in our habitat plots. The left and middle pictures were taken by David Cappaert.

We caught a lot of spiders and harvestmen, mostly in pan and pitfall traps. What’s a harvestman? You might know it by the name daddy long legs. It looks a lot like a spider, but instead of having a distinct narrowed “waist” (actually where the two body segments of the arachnid meet), their bodies just look like single “blobs”. Both spiders and harvestmen are predators and will eat many other insects (including some pests). They may also eat nectar and pollen. Very few spiders you are likely to encounter in New York are venomous, so welcome these eight-legged biocontrol agents to your fields and gardens without fear!

A bar graph showing numbers of spiders and harvestmen caught in each treatment (mostly in pan and pitfall traps). The most spiders and harvestmen were caught in treatments C (spring seeded) and H (grass control). Treatment B (transplanted and mulched) had the fewest spiders and harvestmen.
I added up all of the spiders and harvestmen we caught in each plot, then took the average of these summer-long counts from the four plots of each treatment in our field. The black lines stretching above and below the top edge of each bar show one standard error (measure of variability amongst the four plots) above and below the mean value.

We caught a lot of spiders and harvestmen, but it looks like there were fewer in the plots that were mulched at transplanting or solarized prior to seeding.

Carabid beetles

Top: several tiger beetles with brown backs but iridescent green bellies; Bottom: picture of a black ground beetle taken by Mary C. Legg and available at Bugwood.org
We caught a lot of tiger beetles (top picture) in our plots last summer, but carabid beetles come in many shapes, sizes, and colors.

You may not notice carabid beetles (also called ground beetles) because they crawl along the surface of the soil and are usually more active at night. Also, many of them move very quickly. They are great predators of insects (and other arthropods), as well as mollusks like slugs. Some also eat seeds.

 

 

 

A bar graph showing numbers of carabid beetles caught in each treatment (mostly in pitfall traps). The most carabid beetles were caught in treatments D (fall transplant after buckwheat), F (fall seed after solarizing soil), and G (fall seeding after using tillage and herbicide to control weeds). The fewest carabid beetles were caught in the control plots (E and H).
I added up all of the carabid beetles we caught in each plot, then took the average of these summer-long counts from the four plots of each treatment in our field. The black lines stretching above and below the top edge of each bar show one standard error (measure of variability amongst the four plots) above and below the mean value.

From these preliminary results, it looks like we tended to catch more carabid beetles in the fall-planted treatments (whether they were transplanted or direct-seeded). We’ll have to see if this turns out to be a consistent pattern. There were generally fewer carabids in the two control treatments.

Rove beetles

Two pictures of insects. The one on the left has an arrow pointing to the short wing covers visible on its back (labeled ‘elytra’). The one on the right is courtesy of Joseph Berger, and can be found at Bugwood.org.
Rove beetles come in different sizes, but they all have short wing covers called elytra.

We did not catch very many rove beetles (only 55 in all of the plots for the entire summer), but like carabid beetles these predators live at the soil surface or in the soil. Some also scavenge things that are already dead or eat seeds. You can recognize them by the short wing covers (called elytra) on their backs. I think they look like mini capes.

Hover flies

Left: black and yellow hover fly on a bright yellow coreopsis flower; Middle: a different kind of adult hover fly perched on a person’s skin; Right: a larval hover fly that looks like a small translucent caterpillar on a leaf near a green aphid. This picture was taken by Ken Wise.
Adult hover flies (left and middle pictures) have only two wings and big eyes, even though they are often black and yellow striped like bees. The visually unimpressive larva in the picture on the right is about to eat an aphid.

Hover flies (also called syrphids) come in many shapes and sizes and get their name from the way the adults hover in the air when traveling between flowers. Many look like bees, but if they hold still long enough and you look closely, you will see that they only have two wings (bees have four), and they have very large eyes. The adults feed on pollen and nectar and are also pollinators. The larvae are predators, eating aphids, whiteflies, and scales.

A bar graph showing numbers of hover flies (syrphids) caught in each treatment (mostly in pan traps and sweep nets). More hover flies were caught in direct-seeded treatments (C, F, and G), treatment D (buckwheat during the summer, transplanted in the fall), or the weedy control (treatment E). Fewer hover flies were caught in the spring transplanted treatments (A and B) or the grass control.
I added up all of the hover flies we caught in each plot, then took the average of these summer-long counts from the four plots of each treatment in our field. The black lines stretching above and below the top edge of each bar show one standard error (measure of variability amongst the four plots) above and below the mean value.

We were surprised to see similarly low numbers of hover flies in the two spring transplanted plots (in which deliberately-planted wildflowers were largest and produced the most flowers) and in the mowed grass control. More hover flies were collected from the weedy control, all the direct seeded plots, and the fall transplanted plots (which had smaller wildflowers with fewer blooms). We don’t know why.

Lady beetles

Spiny black and orange larval lady beetle on a green leaf.
Although lady beetles are familiar as natural enemies of pests, their larvae (like this one) are not always so easily recognized. Larvae are often (but not always) elongated, look a bit spiny, and are orange and black.

Lady beetles may be the most well-recognized biocontrol agent, but they were not the most abundant one collected in our sampling. We only collected 65 larvae or adults from all plots over the entire summer. Both life stages are predators, but adults of at least some species will also eat pollen and nectar. We identified the species of each adult (but not the larvae), and a picture of each is below.

From left to right: Pink lady beetle with black spots on a dandelion flower is the pink spotted lady beetle (Coleomegilla maculata); red lady beetle with black spots crawling on a plant stem is a seven-spotted lady beetle (Coccinella septempunctata); another red lady beetle with black spots - including two elongated spots near its rear end that look like parentheses – is the parenthesis lady beetle (Hippodamia parenthesis) whose picture was taken by Whitney Cranshaw, Colorado State University and is available on Bugwood.org; another red lady with black spots is the variegated lady beetle (Hippodamia variegata) and its picture was taken by Frank Peairs from Colorado State University and is available at Bugwood.org; the final lady beetle has a black and orange-yellow checkerspot pattern and is the checkerspot lady beetle (Propylea quatuordecimpuctata) whose picture was taken by Ken Wise with the NYSIPM Program.
We collected adults of these five lady beetle species in our plots during Summer 2019.

Lacewings

Top picture is a magnified picture of an elongated larval lacewing with prominent pincher-like jaws; bottom picture is a green lacewing feeding on pollen from a white buckwheat flower.
Lacewing larva (top) and adult (bottom). Adults may also be brown, but will have a similar shape.

All lacewing larvae are predators, and the more easily recognized adults of some species are also predators. Others eat pollen as adults. We did not catch very many in our plots; only 40 all summer from all plots.

Minute pirate bugs

Small black and white insect, magnified.
Minute pirate bugs may be small, but they are mighty predators!

This may be one of my new favorite natural enemies. They are definitely minute (no more than a quarter of an inch long) but feed on small insect pests like aphids, mites, scales, and thrips, as well as pollen and nectar. We only collected 19 from all plots over the whole summer. At home, I sometimes find them running across my table after I’ve brought freshly cut flowers inside. In this video, you can see one exploring the map of a corn maze. Actually, it was looking for thrips to eat.

minute pirate bug on corn maze map

Bees

Six pictures of different bees. Some are large like bumble bees or carpenter bees, some are smaller, and one is green.
When we think of bees, sometimes we think of just honey bees and bumble bees. But many different bees utilized the pollen and nectar from the wildflowers we planted. Just a few are pictured here.

Interestingly, while we collected a lot of bees of many different kinds over the summer (at least 18 different genera), very few were the iconic honey bees or bumble bees. I have been told by a bee expert that the pan traps tend to catch bees other than honey or bumble bees, and we did set these traps about twice as often as we used sweep nets. So this may have impacted the types and numbers of bees we collected. Nevertheless, these data are a reminder that there are lots of bees out there besides the ones we’re most familiar with. I encourage you to learn more about wild bees of New York.

A bar graph showing the average number of bees caught in each treatment (mostly in pan traps) summed over the entire summer. The most bees were caught in spring-planted treatments (A, B, and C) and the least bees were caught in the grass control treatment (H). The bars contain very small orange (for honey bee) and yellow (for bumble bee sections) sections. The vast majority of bees caught were other wild bees (green).
We caught quite a few bees last summer! However, the vast majority of them were not honey or bumble bees. Importantly, we don’t have bee counts for all sampling dates, yet.

Butterflies

At the beginning of this post, I listed three methods we used to collect insects. Well, actually there was a fourth method, but it was used to count insects rather than to collect them. We did a Pollard Walk through each plot once a month by simply walking along the side of the plot and counting the number and type of butterflies we saw. We counted very few butterflies during these walks, but here are pictures of the species that did visit our plots (either in the adult or caterpillar life stage).

Collage of six different butterflies (Milbert’s tortoiseshell, viceroy, clouded sulphur, red admiral (photo by Daniel Herms, The Ohio State University and available on Bugwood.org), cabbage white (photo by Mary C Legg, available on Bugwood.org), and painted lady) and two caterpillars (monarch and swallowtail).
These are the butterflies we observed in our beneficial insect habitat plots during Summer 2019. Some, like the monarch and swallowtail we only saw as caterpillars; never as adults.

So that’s it for the beneficial insects I’m going to write about today. We also caught some not-so-beneficial insects (and mollusks).

Tarnished plant bugs

Three pictures of tarnished plant bugs, feeding on the stem of a yellow flower, up close, and sitting on a white aster flower.
Tarnished plant bugs have a distinct pattern on their backs, and also benefit from the same floral resources that support beneficial insects.

These are generalist herbivores, feeding on leaves, fruits and flowers of many plants. They can be damaging pests on some fruits (like strawberries) and vegetables. In our plots, I think they caused some damage to the coreopsis flowers. We’re not too worried because they aren’t pests of Christmas trees, but we were disappointed to find the largest numbers of tarnished plant bugs in the more mature habitat plots (those started by transplanting, as opposed to direct-seeding). Other researchers also reported that planting wildflower strips adjacent to strawberries could increase tarnished plant bug populations.

A bar graph showing numbers of tarnished plant bugs caught in each treatment (mostly in sweep nets, but some in pan traps). More tarnished plant bugs were caught in treatments with transplanted wildflowers (A, B, and D), and also quite a few in the weedy control. The fewest tarnished plant bugs were caught in the grass control plots.
I added up all of the tarnished plant bugs we caught in each plot, then took the average of these summer-long counts from the four plots of each treatment in our field. The black lines stretching above and below the top edge of each bar show one standard error (measure of variability amongst the four plots) above and below the mean value.

Leafhoppers

Two different leafhoppers (one yellow and one green) magnified to clearly show their pointy heads and bristled back legs.
There are many different species of leafhoppers out there, but they all have pointy heads that are flattened and bristles on their back legs. The bristles are much easier to see with magnification, as in these pictures.

Leafhoppers are another insect that we aren’t too concerned about with Christmas trees, but can be a pest of other crops. I learned that you can distinguish this group of insects by their pointy flattened (top to bottom) heads and the bristles on their back legs. The spring transplanted plots in which wildflower plants were most mature and produced the most blooms also had fewer leafhoppers than other treatments.

A bar graph showing numbers of leafhoppers caught in each treatment (mostly in pan traps, but many in pitfall and sweep nets, too). Although we caught a lot of leafhoppers, we caught fewer in the treatments where wildflowers were transplanted in the spring (A and B).
I added up all of the leafhoppers we caught in each plot, then took the average of these summer-long counts from the four plots of each treatment in our field. The black lines stretching above and below the top edge of each bar show one standard error (measure of variability amongst the four plots) above and below the mean value.

 

Slugs

Slimy slug being held next to a ball point pen for size comparison. The slug is about one third the length of the pen.
Biggest slug of 2019 insect sampling!

As I mentioned at the beginning of this post, slugs are mollusks, not insects (or even arthropods) and they can be pests of many different crops. The picture above is definitely the largest slug that we collected during 2019. Interestingly, there seemed to be fewer slugs in the plots where we solarized the soil during the 2018 growing season. I was interested to learn that soil solarization is known to kill slug eggs, and I wonder if we’re seeing that effect here. I don’t know how far slugs move from where the eggs hatch, and it will be interesting to see if this effect persists in future years.

A bar graph showing numbers of slugs caught in each treatment (mostly in pitfall traps, but some in pan traps). We caught fewer slugs in the plots that were solarized and had wildflowers direct seeded in the fall (treatment F) than in other treatments.
I added up all of the slugs we caught in each plot, then took the average of these summer-long counts from the four plots of each treatment in our field. The black lines stretching above and below the top edge of each bar show one standard error (measure of variability amongst the four plots) above and below the mean value.

Believe it or not, this is not the full list of insect (or arthropod, mollusk, or annelid) groups we collected and counted. Also, I will remind you again that these data (especially the bee data) are preliminary. Although I’m sad to be unable to collect insects this summer due to COVID-19, I’m looking forward to finishing the analysis of the 2019 data and getting ready to hopefully collect insects again in 2021. In the meantime, you can see pictures of what’s happening in these plots throughout the summer on my Twitter and Instagram accounts. And I will write at least one more post about this project later this year.

 

This post was written by Amara Dunn. All pictures or videos were taken by her, unless otherwise credited.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation

Conservation biocontrol in the time of COVID-19

rows of small Christmas tree seedlings in a field on a sunny day, with a pond in the background
I was so excited to check on our Christmas tree and beneficial insect habitat plots on this sunny May day!

Thanks to everyone who’s been following the project I’ve been working on with Betsy Lamb and Brian Eshenaur to establish (and document the impacts of) habitat for natural enemies of pests and pollinators (collectively, beneficial insects) around a research planting of Christmas trees! For many people, life does not look the same as it did in January, and we are no exception. Don’t worry, we and the excellent Field Research Unit staff at Cornell AgriTech will be maintaining our research beneficial insect habitat plots (and the Christmas trees around them) so that we can continue to do research here in future years. But, in the interest of keeping people safe and working remotely as much as possible, we won’t collect insects this season. I will be going out about once a week to take pictures of both plants and insects (by myself, with a mask on hand just in case). You can see these pictures on either my Twitter or Instagram accounts.

Clusters of still-closed yellow flower buds
Zizia aurea (golden alexander) is the earliest-blooming plant species we have in our beneficial insect habitat plots. And it wasn’t blooming yet the first week of May.

There’s also a new project you can follow this spring and summer (here, and on Twitter and Instagram)! I recently moved into a new house, and was already planning to put in a (mostly flower) garden, including plants that support beneficial insects. Since many people are doing more things at home, this seemed like a good year to share my experience establishing habitat for beneficial insects in a home garden.

First step? Site selection. My backyard is a bit shady (and I suspect it will be shadier when the leaves come out). You can’t tell from this picture, but the ground also tends to be a little squishy after it rains.

Lawn with shadows from nearby trees
Even before the leaves have come out, I can tell that my backyard is not going to be the sunniest.

The front and side yards face south and west and are drier.

Lawn along the side of a house that is mostly sunny
The side yard at my house faces south, and gets more sun (except first thing in the morning).

In my experience, the list of plants that support beneficial insects is longer if you have plenty of sun and reasonably dry soil. This doesn’t mean that you can’t support beneficial insects in a wet and/or shady spot. But you need to choose plant species carefully. You will be more successful if you choose plants that will thrive in the conditions you have. More on plant selection in a later post.

In addition to simple aesthetics, another important part of site selection around the home is knowing what’s underneath the ground. My local utility company provided information about getting water, gas, electric, and internet service lines on my property marked before I start digging. They recommended marking these lines even if I’m just planning to dig by hand with a shovel. If you are planning to use larger equipment, this is even more important (and may be required, depending on where you live). Better safe than sorry. Call before you dig!

Sunny lawn with a stripe of yellow paint and and a yellow flag marking the buried gas line
My buried gas line runs through the side yard. I got it marked before I started digging.

Out of an abundance of caution, I’m going to use the location of the buried gas line on my property as a good place to locate a path (rather than a flower bed that requires digging).

I’ll talk more about weed control in a future post, but when you are selecting a site (and deciding how big an area you want to plant), you should also be thinking about how you are going to manage weeds. I am planning to get mulch. But I have resigned myself to the fact that I may be doing some extra hand weeding this summer. It will be a good activity to get me out of the house in the evenings and on the weekends.

Stay tuned for more updates on this project!

 

This post was written by Amara Dunn, Biocontrol Specialist with the New York State Integrated Pest Management Program. All pictures in this post were taken by her.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation

Creating habitat for beneficial insects: Time, money, and weeds

On the left is a picture of a woman in a sundress and straw hat standing in the middle of a sunny sunflower field with her arms raised in the air. Written at the top of the picture is the title “What I thought establishing habitat for beneficial insects would be like…”. On the right is a picture of three people, either on their hands and knees or bending over, pulling weeds (including dandelions) that are several feet tall. This picture has the title: “What it’s actually like.”In December, I updated you on how perennial wildflowers and grasses were establishing in our beneficial insect habitat plots during the 2019 growing season. As I wrote that post, I quickly realized that there was too much good information for just one post. So here’s the rest of the story when it comes to plant establishment – time, money, and weeds.

Before I get started, below is a quick reminder of what our treatments were. You can read all the details here.

Treatment Description
A Spring transplant, no mulch
B Spring transplant with mulch
C Spring direct seed
D Buckwheat cover crop, then fall transplant
E – control Whatever was growing there, just keep it mowed
F Soil solarization, then fall direct seed
G Herbicide and tillage, then fall direct seed

Weed control

One thing that has surprised me about this project (although others certainly gave me fair warning) was how big a role weed management plays in establishing habitat for beneficial insects. It’s definitely still a struggle in our plots.

Bryan Brown did weed assessments for us in May and September of 2019. The graph below shows the average percent of the area of each plot covered by either weeds (orange) or beneficial habitat flowers and grasses (blue).

Bar graph shows the average percent of plots covered with either weed or beneficial habitat plants in May 2019. Weed control in the treatment (B) where transplants were mulched had the best weed control. The worst weed control was in treatment D, where seedlings were planted in Fall 2018 after a buckwheat cover crop.
Mulching provided the best weed management when plots were assessed in May of 2019. Each bar shows the average of four plots per treatment, and has an error bar showing variation among these plots (one standard error above or below the average for the treatment).

This was before we did any hand-weeding. By far, the plots that were mulched in Spring 2018 (treatment B) had the fewest weeds compared to beneficial habitat plants. You’ll also notice that in May there were still relatively few weeds in the plots where we tried to deplete the weed seed bank in the soil through solarization (treatment F) or repeated herbicide and tillage (treatment G).

Picture on the left is of treatment B (Spring transplant and mulch) and shows small wildflower plants surrounded by mulch and few weeds. The middle picture shows treatment C (spring direct seed), a weedy plot. The picture on the right shows treatment F (solarization and fall direct seed), where you can still see at least 50% of the plot is bare soil, although many small and a few larger weeds are visible.
What some of the plots looked like on May 16, 2019 when Bryan did the weed assessment.

By September 2019, the spring transplant treatments looked even better. Our wildflowers grew well during 2019 (with the help of some extra hand weeding). The plants we transplanted in Fall 2018 are still struggling and not nearly as large as the wildflowers in treatments A and B. I think this may have more to do with the weed competition they experienced that first fall (when we couldn’t plant for a few weeks after the buckwheat was mowed) than transplant timing. Hopefully they will catch up.

Picture on the left is of treatment A (spring transplant, no mulch) and shows tall wildflower plants with some weeds. The middle picture shows treatment B (Spring transplant and mulch), full of large wildflowers and few weeds. The picture on the right shows treatment D (buckwheat and fall transplant), where the wildflower plants are much smaller, there are more weeds, and some bare ground is visible.
What some of the plots looked like on September 19, 2019 when Bryan did the weed assessment.

There are still a lot of weeds in the direct-seeded treatments (C, F, or G). Remember that our weed management strategy in these plots is repeated mowing to control annual weeds. Over time, the perennial wildflowers and grasses should take over. But it’s not supposed to be a quick method.

Bar graph shows the average percent of plots covered with either weed or beneficial habitat plants in September 2019. Weed control in the treatment (B) where transplants were mulched still had the best weed control. The worst weed control (besides the control plot where no beneficial habitat plants were planted) was in the three treatments using spring or fall direct seeding (C = spring direct seeding, F = soil solarization and fall direct seeding, G = herbicide and tillage with fall direct seeding).
Spring transplant treatments (A and B) looked the best after their second full growing season. The fall transplants (D) had more weeds, but these plants also have been in the ground for one less growing season. I’m still hoping they will catch up. Each bar shows the average of four plots per treatment, and has an error bar showing variation among these plots (one standard error above or below the average for the treatment).

Effort

Most of the treatments we are comparing required much less work in their second year (2019) than in their first (2018). The exception is that we spent a lot more time hand weeding treatment D (buckwheat cover crop followed by fall transplanting) in 2019. Although we weeded the two spring transplanted plots the same number of times in 2019 (twice), it took longer to hand weed the plots without mulch. I’m not surprised. If you’re looking for the right establishment method for your project, you really need to ask yourself how much help you have available and when. If you can get a lot of people excited about helping you install the planting, but worry about getting consistent volunteers year after year, mulch may be the right choice for you. In the direct seeded treatments (C – spring; F – fall following solarization; G – fall following herbicide and tillage), the time input for 2019 was mowing, which was relatively quick. And we did just a little hand weeding of perennial weeds.

Bar graph shows time (in person hours) spent on each treatment for both 2018 (in blue) and 2019 (in orange). The tallest bars are for treatments A, B, and D, but most of the bar for treatment B is blue (representing transplanting, mulching, and hand weeding in 2018). For treatment D, half the bar is orange (representing hand weeding in 2019). Treatment A shows more orange than treatment B, but less than treatment D.
Transplanting (treatments A, B, and D) still takes more time than direct seeding, but the extra time we spent mulching in 2018 paid off in 2019 when we spent less time hand weeding (treatment B compared to A and D).

Costs

Nearly all of our costs were incurred in the first year of the project (2018). The only additional costs from 2019 were for gas to run the mower. We did replace a few plants in transplanted plots in Fall 2019, but we used some extra plants we had purchased in 2018. Below is the total cost of the plants and other supplies for each treatment. Transplanting will always be more expensive than direct seeding.

Treatment Costs
A $417.12
B $539.29
C $18.83
D $390.55
E $3.40
F $149.10
G $23.12

 

You may remember that we were also collecting insects. I promise I will write more about the insects we caught in another post. If you are tired of looking at snow and bare trees outside, you can see pictures of some of the insects we caught in my post from August 2019.

This post was written by Amara Dunn. All pictures were taken by her, unless otherwise credited.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation

Creating habitat for beneficial insects: How are things growing?

Planting of purple, yellow, and white flowers with blue sky in the background
Lots of flowers bloomed in 2019 in our habitat plots. Some we had planted, and some we hadn’t.

Obviously, nothing is growing right now, but I thought this would be a good time to update you on the success of our beneficial insect habitat plots during the 2019 growing season.

When things bloomed

Recall that the goal is to have at least one plant blooming all season long. We choose wildflower species accordingly, and it worked! The following table shows which months each species bloomed in 2019 (at least in the transplanted plots). An ‘X’ means the species was blooming during that month.

Wildflower May June July Aug Sep
Golden alexanders X X
Catmint X X X  X
Lanced-leaved coreopsis X X
Tall white beard tongue X X
Ohio spiderwort X X
Anise hyssop X X  X
Echinacea X X  X
Orange coneflower X X  X
Boneset X X X
Wild bergamot X X
Common milkweed X
NY ironweed X  X
Showy goldenrod  X
New England aster  X
Blue false indigo

You may notice that the blue false indigo never bloomed in 2019, which was disappointing. Most of these plants are still alive (as you’ll see later in this post). They just didn’t bloom. Maybe next year?

Here’s what each species looks like:

Plant with tiny yellow flowers arranged like Queen Anne’s Lace.
Golden alexanders (Zizia aurea)
Small purple bell-shaped flowers on stems with frosty-green leaves
Catmint (Nepeta faassinii)
Yellow daisy-shaped flowers with toothed edges
Coreopsis (Coreopsis lanceolata)
Clusters of white or pink bell-shaped flowers on top of tall stems
Tall white beard tongue (Penstemon digitalis). Obviously not all of these flowers are white!
Three-petaled purple flowers growing on plant with grass-like leaves.
Ohio spiderwort (Tradescantia ohiensis)
Small, pale purple flowers clustered at the top of a stem
Anise hyssop (Agastache foeniculum)
Pink daisy-shaped flowers with organge centers
Echinacea (Echinacea purpurea)
Large clump of daisy shaped flowers with yellow petals and dark brown centers
Orange coneflower (Rudbeckia fulgida var. fulgida)
Small white flowers in flat clusters
Boneset (Eupatorium perfoliatum)
Pale pink-purple flowers that look like small tufts on the top of stems
Wild bergamot (Monarda fistulosa)
Pale pink flowers with 5 sets of petals and a complex shape
Common milkweed (Asclepias syriaca)
Bright magenta flowers formed into small tufts at the top of the plant
NY Ironweed (Vernonia noveboracensis)
Large clump of small, bright yellow flowers
Showy goldenrod (Solidago speciosa)
Purple daisy-shaped flowers with yellow centers and very narrow petals. A small bee is visiting one of the flowers
New England aster (Symphyotrichum novae-angliae)
Pale blue-purple legume flowers. One is being visited by a bumble bee
Blue false indigo (Baptisia australis); hasn’t bloomed yet in our field. Photo credit: Ansel Oommen, Bugwood.org

Transplanted wildflowers

The wildflowers in our transplanted plots are surviving pretty well (>80%). In the plots that were transplanted in the fall after the buckwheat cover crop, the survival is a bit lower. I think this has to do with some weed control issues (more on this in a future post).

Percent of plants surviving was lowest in treatment D, but still above 80%. Survival did not change very much from Spring to Fall 2019.
How well have the transplanted wildflowers survived so far? Treatment A was transplanted in Spring 2018 and not mulched. Treatment B was transplanted in Spring 2018 and mulched. Treatment D was transplanted in Fall 2018 following a buckwheat cover crop. All have been hand weeded periodically. In both Spring and Fall of 2019 I counted plants to see how well they survived. The black lines on each bar in the graph show one standard error above and below the mean percent survival.

Some species have survived better than others, as the following chart shows. Again, we counted plants both in Spring and Fall 2019.

Bar graph showing the mean percent of plants of each species that were still alive in Spring and Fall 2019. With the exception of milkweed, all survival rates were at or above 80%, and losses were minimal from Spring to Fall.
Do some species of wildflowers survive better when transplanted? There’s a little bit of variability, but overall most are surviving pretty well.

What about the direct-seeded plots?

Only three species of wildflowers planted by seed in Spring or Fall 2018 bloomed during the 2019 season. The table below shows which months these blooms were seen (marked with an ‘X’).

Common name May June July Aug Sep
Coreopsis X X X
Blackeyed susan X X X
Partridge pea X X

Here’s what the flowers of blackeyed susan look like. The plant has much hairier leaves than the orange coneflower.

A daisy-shaped flower with yellow petals and a dark brown center
Blackeyed susan (Rudbeckia hirta)

And here’s the partridge pea:

Yellow flower with compound leaves cupped in a person’s hand
Partridge pea (Chamaecrista fasciculata)

But, I also spotted some wild bergamot, tall white beard tongue, asters, golden alexanders, and either echinacea or orange coneflower seedlings. (I haven’t honed my horticultural skills enough yet to distinguish the foliage of these last two wildflowers.)

Pictures of seedlings labeled (left to right, top to bottom) aster, golden alexanders, echinacea or orange coneflower, wild bergamot, and beard tongue.
Seedlings of some wildflowers could be identified in the direct-seeded plots by September 2019.

There were also plenty of weeds blooming throughout the summer, and many of them were providing pollen and nectar for pollinators and natural enemies. Here are just a few examples:

Four pictures showing a bee on a yellow flower, several daisy-shaped flowers with white petals and yellow centers, a yellow dandelion with a pink lady beetle on it, and a bumble bee visiting a pink clover flower
From left to right: A bee feeding on a weed in the aster family, blooming chamomile, a lady beetle on a dandelion, and a bumble bee visiting clover (that wasn’t planted).

This table summarizes when during the season different weeds were in bloom. Again, an ‘X’ indicates the weed was blooming that month.

Weed May June July Aug Sep
Campion X X X X X
Chamomile X X X X X
Clover X X X X X
Dandelion X X X X X
Vetch X X X X X
Viola X X X X X
Mustard X X X X
Deadnettle X X
Baby blue eyes X
Henbit X
Asters X X X X
Buckwheat X X X X
Oxalis X X X X
Plantain X X X X
Wild lettuce X X X X
Cinquefoil X X X
Indian hemp X X X
Redshank X X X
Chickweed X X
Galinsoga X X
Geraniums X
Sandwort X
Grass X X
Horse weed X X
Lambsquarters X X
Ragweed X X
Black bindweed X
Chicory X

There’s more!

In addition to keeping track of what bloomed from May through September, we were also still tracking costs and time spent on each plot in 2019. And of course we collected a LOT of insects. But those stories will have to wait for another post.

This post was written by Amara Dunn. All pictures were taken by her, unless otherwise credited.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation

Come visit our beneficial insect habitat plots!

In the foreground you can see a small Christmas tree. In the background, you can see a patch of mixed wildflowers. Behind it are trees, and partly cloudy sky, and a pond.

You’ve read about all the different methods we are testing for establishing native wildflowers and grasses as habitat for pollinators and natural enemies of pests. You know we learned a lot in our first season. You know we’ve been using several different techniques to collect insects in these plots. And you saw a pictorial summary of our sampling and some of the insects we’ve caught in Summer 2019.

Wouldn’t you like to come see these plots in person, hear about our preliminary results, and learn more about attracting pollinators and other beneficial insects to your farm or yard?

If you live reasonably close to Geneva, NY, you can! We are having two field events this fall:

On Wednesday, September 25, 2019, stop by our field between 3:30 and 6:30 PM for an Open House. There will be no program, just stop by and talk with Betsy Lamb, Brian Eshenaur, and I. All the details can be found here, including the address and a map to help you find our field.

On Thursday, September 26, 2019, we have a Twilight Field Day from 5 to 7 PM. This meeting has been planned with growers in mind (especially Christmas tree and nursery growers). DEC credits (1.5) will be available for categories 1a, 3a, 24, 25, and 10, and dinner is included. The cost for this meeting is $15, and we need you to register so we know how much food to provide. All the details (including the registration link) can be found here.

If you’re coming to either of these events, we’ll have lots of signs up to help you find our field. Look for the following image:

illustration of a pink daisy-shaped flower with orange center and a Christmas tree, next to the logo for New York State Integrated Pest Management

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation

A summer of biocontrol…in pictures

Several types of wildflowers (yellow, white, deep magenta, purple, pink) growing in a field.
Summer isn’t over yet for farmers and extension staff doing field experiments!

Labor Day weekend may be viewed by some as the end of summer, but farmers know that the summer growing (and harvesting!) season is far from over. Similarly, the field projects I’m involved with this summer (read more here and here) are still running. Over the fall and winter I’ll be analyzing data and sharing results (on this blog, and at winter meetings). In the meantime, here’s a pictorial summary of my summer projects (so far).

Plant whose leaves have 3 lobes (like elongated clover leaves) with toothed edges. Flower is an open cluster of tiny yellow flowers, similar to Queen Anne’s Lace.
Golden alexanders (Zizia aurea) was our earliest-blooming wildflower in our beneficial insect habitat plots around the Christmas trees. It was blooming on May 16 in Geneva, NY.
A bee already covered in fine yellow dust looks for nectar and (more) pollen in a dandelion bloom.
Some of us may not like them in our lawns, but starting in the first week of May (Geneva, NY) dandelions were providing food for beneficial insects like this bee.
You can see the rear-end of a lady beetle (red body, with black spots) as it searches for pollen and nectar among small, bright yellow flowers.
This shy lady beetle was finding food in the flowers of this weedy mustard plant in mid-May (Geneva, NY).
Man walking through a field of grass on a cloudy day, swinging a long white net on a long wooden handle just above the ground.
After expert training from Cornell entomologist Jason Dombroskie (pictured here during our training session in late April), we’ve been using a sweep net to catch insects that fly or perch on the wildflowers in the habitat plots we started last summer. We sampled this way once every month.
One blue and one yellow bowl filled with soapy water and rocks set on ground covered with wood chip mulch. Several different types of plants are growing nearby.
Starting the week of May 20th, we set out pan traps (blue and yellow plastic bowls filled with soapy water and weighed down with rocks) approximately every other week. These traps catch insects flying through our plots, especially those that are attracted to the colors blue and yellow. This includes many bee species.
Various types of weeds and other plants grow around a spot where a deli cup is buried up to the rim in the ground. The deli cup is also full of liquid. Suspended over the deli cup on “legs” of thick wire is a clear-plastic dinner plate.
Also during the week of May 20th, we started setting pitfall traps once each month. Insects walking along the ground fall into these deli cups filled with a drowning solution. We put rain covers over them (made out of clear plastic dinner plates and wire from old flags) to prevent a heavy rain from flooding the deli cups during the 3 days the traps are set.
A red lady beetle with 7 spots on its back crawls across a green stem of vetch that is being held by a hand that is dirty (probably from weeding).
We caught and saw so many insects (and non-insects, like spiders) this summer! This seven-spotted lady beetle was a frequent visitor to our plots.
A fly with big eyes and black and yellow stripes on its body perches on a yellow coreopsis flower, probably looking for pollen and nectar.
Many flies are important pollinators, like this one that resembles a bee at first glance. Many flies are also important natural enemies of pests (either as adults, or as worm-like larvae).
Small insect with eyes that bug out to the sides of its head, triangular and diamond-shaped black and white patches on its otherwise brown wings and body.
This minute pirate bug may be tiny (it’s magnified 20X), but it is an important natural enemy of pests.
Looking down into a clear plastic cup that contains eleven different bees and wasps, ranging from a large bumble bee to tiny wasps that you can barely see.
We caught so many different kinds of bees and wasps!
Two black, yellow, and white striped caterpillars feed on the broad green leaves of a milkweed plant.
Plenty of caterpillars (like these monarchs) enjoyed munching on the foliage of our wildflowers.
A black and orange striped butterfly visits a daisy-shaped flower with pink petals and an orange cone-shaped center.
And in late July, we started seeing adult butterflies visiting the flowers like the viceroy butterfly on these purple coneflowers (Echinacea purpurea).
Eight beetles with eyes that bug out from the sides. They look brown when viewed from the top, but when viewed from underneath they look iridescent blue-green.
I learned that these are tiger beetles. They are fast-moving ground predators, and we caught a lot in our pitfall traps.
Plant stems covered in small purple flowers in the background, and plant stems covered in large white bell-shaped flowers in the foreground.
Different wildflowers bloomed at different times, like these purple catmint (Nepeta faassinii) and tall white beard tongue (Penstemon digitalis) in June.
On left, an open cluster of tiny white, slightly fuzzy flowers. On the right, flowers that look like pale purple puffs at the top of the stems.
White boneset (Eupatorium perfoliatum) and pale purple wild bergamot (Monarda fistulosa) were blooming in late July.
In the foreground, daisy-shaped flowers with yellow petals and black centers. In the background, a tall plant with open clusters of deep magenta flowers that look slightly fuzzy. You can see a field and blue sky in the background.
And now the rudbeckia (two different species, but Rudbeckia fulgida var. fulgida is pictured here) and deep magenta NY ironweed (Vernonia noveboracensis) are in full bloom. But the asters and goldenrod haven’t started, yet.
Short Christmas trees, planted in rows with grass in between. A pond, several fields, a line of trees, and a cloudy sky are in the background.
And the Christmas trees planted around these beneficial insect habitat plots keep growing!
Three people (two women and a man) wearing work clothes, holding gardening tools, and standing in the middle of a field with some yellow flowers in the foreground and a cloudy sky in the background.
I couldn’t have done this without the help of my great co-workers, Betsy Lamb, Deb Marvin, and Brian Eshenaur! They were still smiling after a morning of weeding the wildflowers by hand!
Smiling young woman holding a sheet with pictures of butterflies, and standing next to blooming purple coneflowers. You can see a field in the background.
A student from a local college helped me a lot with insect collection!
Several rows of cucurbit plants just starting to flower. In the background, you can see a road, a field, and a barn.
Meanwhile, field trials with biofungicides are ongoing, targeting cucurbit powdery mildew on winter squash and white mold on snap beans and tomatoes (not pictured). This project is funded by the New York Farm Viability Institute.
: Two women, both in red shirts, standing in the middle of a field. One holds two weeds. The other holds a clipboard and a water bottle.
Elizabeth Buck (left) and Crystal Stewart (right) are running the trials in western NY and eastern NY, respectively. This project is funded by the New York Farm Viability Institute.
Woman on left is wearing a red shirt, talking, and gesturing with her hands. Woman on right in wearing a green shirt and watching and listening to the woman on the left.
Meg McGrath (left) is running the trial on Long Island, but we all got together at a twilight meeting in eastern NY last week. This project is funded by the New York Farm Viability Institute.
Woman in a blue shirt and baseball cap looking into the camera. In the background you can see white bell-shaped flowers and blue sky with a few puffy clouds.
So far, it’s been a good summer! I’ve really enjoyed working with great colleagues and learning new things!

The field projects I’ve just described will be wrapping up in September. Check back to learn about the results. Better yet, click the green “Subscribe” button towards the top and right of this page, and you’ll receive an email when a new post is available!

 

In the meantime, there will still be at least a few more weeks of pictures posted regularly on Twitter (@AmaraDunn) and Instagram (@biocontrol.nysipm).

Biofungicide project was funded by the New York Farm Viability Institute.

Creating habitat for beneficial arthropods was supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation

Creating habitat for beneficial insects: Starting Year 2

A close-up picture of a lady beetle on a plant
Lady beetle from our beneficial insect habitat plots

Last year I introduced you to the research field at Cornell AgriTech in Geneva, NY where Dr. Betsy Lamb, Brian Eshenaur and I are studying and demonstrating Christmas tree IPM. One part of this project is using perennial wildflowers to attract natural enemies of pests as part of an IPM strategy. The wildflowers (and some perennial grass) species were chosen because of the food and shelter they provide to pollinators. These same resources should make them useful to natural enemies of pests, too.

A plot containing wildflowers (some yellow and purple ones in bloom), with woodchip mulch visible between plants.
Mulching transplants planted in Spring 2018 was the most expensive establishment method, but these plots were looking pretty good a year later, even before we weeded.

By the end of our first field season, we had started using six different methods to establish wildflowers as habitat for beneficial insects (plus a weedy mowed control treatment). We also collected data on how much time and money we spent on establishment and how successful our weed management was. You can read about results from Year 1 in my post from last November.

But beneficial insect habitat establishment is not a one-year project. The establishment methods we started to implement in 2018 are ongoing, including periodic mowing of direct seeded plots, and hand-weeding of transplanted plots. We’ll keep track of how much time and money we invest in these plots in 2019, too.

The same plot is shown in two pictures. The picture on the left has some bare ground visible and many patches of grass and broadleaf weeds. The picture on the right shows the plot after it was mowed.
Plots that were direct seeded in 2018 will be mowed this year to favor the perennial beneficial insect habitat plants over annual weeds. This plot was treated with alternating herbicide and tillage during Summer 2018, and wildflower seed was planted in Fall 2018; (A, left) plot before mowing, (B, right) same plot after mowing.
Two pictures of the same plot before (left) and after (right) weeding. The un-weeded plot has lots of dandelion seed heads and no bare ground is visible. After weeding, you can see some bare ground and it’s easier to see the wildflower plants.
Plots that were transplanted in 2018 will be hand weeded this year to help the perennial wildflowers and grasses out-compete weeds. This plot was transplanted in Spring 2018 into bare (not tilled) ground and no mulch was used; (A, left) plot before weeding, (B, right) same plot after weeding.

And we want to know whether these plots are actually attracting beneficial or pest insects. So, in 2019 we are starting “Phase II” of our beneficial insect habitat work. We want to know which and how many insects (and other arthropods, like spiders) are being attracted to each type of plot. We will also count insects in no habitat plots (weedy, mowed occasionally) and mowed grass plots in the middle of the Christmas tree field for comparison.

Insect collection began in early May, and we are using four different techniques:

  • Sweep net – This is what it sounds like. We “sweep” a net through the air above the ground to capture mostly flying insects, or those who may be resting on the plants.
  • Butterfly and moth count – We walk through the field, counting how many of each butterfly or moth species we see in each plot.
  • Pan traps – These are bright yellow and blue bowls filled with soapy water. One bowl of each color is placed in each plot for 2 days, then we collect the insects that have been attracted to the colorful bowls and were trapped in the soapy water. This method will help us count flying insects, especially bees and wasps.

    A bright blue plastic bowl and a bright yellow plastic bowl are filled with soapy water and small rocks. Both are set on bare ground with some plants growing nearby.
    Bright blue and yellow bowls filled with soapy water and weighed down with rocks will attract certain flying insects. By counting insects collected in these pan traps, we can learn which insects are spending time in each plot.
  • Pitfall traps – These are clear plastic 16-oz deli cups (like you might use for take-out food) that are sunk into the ground in each plot. Insects that crawl along the ground fall in. We will use this method to count mostly ground-dwelling insects.

    A 16-ounce plastic deli cup sunk in bare soil of a plot so that the rim is level with the ground. The cup is half-full of liquid and also has caught a few green beetles. The trap is covered by a clear plastic dinner plate held about 6 inches above the ground by wire legs.
    A pitfall trap collects ground-dwelling insects. This one is protected by a rain cover. We didn’t want all the rain we’ve been getting this spring to overflow the traps and wash away the insects we caught!

I will write another blog post or two about this project during or at the end of this season. If you want to see more frequent updates, follow me on Twitter (@AmaraDunn). I’ll post weekly pictures of this project, including which beneficial insect habitat plants are blooming each week. You can also see lots of pictures from this project on Instagram (biocontrol.nysipm).

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets
  • Towards Sustainability Foundation

Creating habitat for beneficial insects: Project update at the end of the first year

Fair warning, this is going to be a longer post. But partly that’s because there are so many pictures. I will start with the overview, then go a bit deeper into the weeds (literally and figuratively). To help you navigate more quickly, here’s a sort of table of contents that will quickly take you to the information you may be most interested to read:

Overview

Details on weed control

Timing of fall planting

The steps we followed to establish beneficial insect habitat

mixed wildflowers in a field
Some of our beneficial insect habitat plots looked really beautiful this fall! Others are still works in progress.

Overview
Remember back in June when I told you about the different techniques we were comparing for establishing habitat for beneficial insects? Time for an update! Here’s a brief, two-page summary of the first year of this project. For all the juicy details (and lots of pictures), keep reading!

First, remember that when I say “beneficial insects”, I mean both pollinators and natural enemies of pests. (Technically, arthropod would be a better term than insect, because spiders and predatory mites are some of the beneficial creatures we’d like to attract.) Fortunately, the same type of plants provide food and shelter for both pollinators and natural enemies on your farm or in your garden.

We used six different techniques to establish this habitat during Spring, Summer, and Fall of 2018. Treatment E was our control, where we did nothing but mow (after initial herbicide applications).

Treatment Fall 2017 Spring 2018 Summer 2018 Fall 2018
A Herbicide Herbicide, transplant  Weed 2x Replace dead plants
B Herbicide Till, transplant, mulch Weed 2x Replace dead plants
C Herbicide Till, direct seed Mow 3x Mow 1x
D Herbicide Till, plant buckwheat Mow 1x, till, plant buckwheat Mow 1x, transplant
E – control Herbicide Herbicide Mow 3x Mow 1x
F Herbicide Till, lay plastic Continue solarization Remove plastic, direct seed
G Herbicide Herbicide/till Herbicide 2x, till 1x Till 1x, direct seed

We transplanted the following species in treatments A, B, and D:

Common name Scientific name Number of plants in each 5 x 23 ft plot
Anise hyssop Agastache foeniculum 2
Common milkweed Asclepias syriaca 3
Blue false indigo Baptisia australis 2
Lanced-leaved coreopsis Coreopsis lanceolata 3
Purple coneflower Echinacea purpurea 2
Boneset Eupatorium perfoliatum 3
Wild bergamot Monarda fistulosa 2
Catmint Nepeta faassinii 2
Tall white beard tongue Penstemon digitalis 3
Black-eyed Susan Rudbeckia fulgida va. Fulgida 1
Little bluestem (grass) Schizachyrium scoparium 11
Showy goldenrod Solidago speciosa 1
New England aster Symphyotrichum novae- angliae 3
Ohio spiderwort Tradescantia ohiensis 2
NY ironweed Vernonia noveboracensis 2
Golden alexanders Zizia aurea 3

We planted seeds in treatments C, F, and G. The seed mixture we used was the Showy Northeast Native Wildflower & Grass Mix from Ernst Seeds, which included a more diverse species mix. This mix changes a bit from year to year. If you’re interested, you can learn about the details of the specific mix we used here.

 Labor and costs

Not surprisingly, there were big differences in how much time and money we spent on different treatments this first year. The costs and hours below are for a total area of 460 ft2 (0.01 A) per treatment. Most of the cost differences are due to the huge difference in seed versus transplant expenses. We paid about $2 per plant and needed 180 plants for each treatment. In contrast, we spent about $12.50 on seed for each treatment. You can find itemized lists of cost and time inputs for each treatment here.

Treatment Supply costs Time (person hrs)
A – spring transplant $417.12 13.2
B – spring transplant & mulch $539.29 20.4
C – spring seed $17.75 4.4
D – buckwheat & fall seed $390.55 10.3
E – control $2.32 2.6
F – solarize & fall seed $148.02 10.2
G – herbicide/tillage & fall seed $22.04 6.3

But, there were also big differences in how quickly the plants established. By September, both treatments (A and B) that had been transplanted in the spring looked like well-established gardens, with large, blooming wildflowers.

Transplanted plots with more weeds (left) and fewer weeds (right). Plot on the right had been mulched.
Four and a half months after transplanting, the beneficial habitat plants in treatments A (left) and B (right) were mostly growing well. But there was a big difference in weed control, in spite of similar amounts of time spent weeding each treatment.

We were generally pleased by how well most of the spring transplants survived. Although all the transplants came in 50-cell flats, some were larger than others, and the larger transplants survived better. We were fortunate to be able to plant into nice moist ground, so except for a little water on the day of transplanting, we didn’t irrigate. Survival might not have been as good if we’d had different planting conditions.

In contrast, the much less expensive treatment C was not looking too impressive even by October. A few partridge peas and blackeyed Susans bloomed this year, but otherwise it didn’t look much different from the control plots. In mid-summer, it looked like we were growing more ragweed than wildflowers.

Mower cutting ragweed (left) and mowed weedy mix with a few yellow flowers blooming.
In late July, it looked like we were growing mostly ragweed in treatment C (left). But after mowing four times during the summer and fall, you could definitely see the blackeyed Susans establishing (right).

Two of the treatments (F and G) were planted with seeds this fall, and one treatment (D) was transplanted this fall. So it’s really too early to tell how successful those treatments were. Stay tuned for more updates!

Mixture of mowed weeds with small plants (left), plot of bare ground (middle and right)
Fall transplanted (D) or direct seeded treatments (F and G) did not look very impressive by October 19, 2018. I’m curious to see what they look like next spring, summer, and fall!

Details on weed control

What about weeds? The graph below shows the average percent of the surface area of each plot that was covered with weeds versus planted beneficial habitat species on September 19, 2018. (Thank you, Bryan Brown, NYS IPM Integrated Weed Management Specialist for doing a weed assessment for us!) While we spent about the same amount of time weeding treatments A and B (the time difference is due to the time spent mulching treatment B), we achieved much better weed control with the mulch than without it!

Bar graph showing how much of each plot area was covered by weeds and by beneficial plants for each treatment
Bryan Brown assessed the percent of each plot that was covered with either the beneficial habitat species we had planted (blue) or weeds (orange). Each bar represents the average of four plots for each treatment, and the error bars show the standard error.

In treatment B, we spread chipped shrub willow mulch about 3 inches deep around the transplants. If I were to do this again, I would spread it thicker. I was disappointed with how many weeds were growing through the mulch just a month after transplanting.

mulched plot with lots of weeds on the left and fewer weeds on the right
The chipped shrub willow mulch we used was not as effective at suppressing weeds as I had hoped. On the left is part of the plot that had not been weeded yet. On the right is the part that was weeded on July 6. You can also see from this picture that there was a lot of lambsquarters in this field, and that we hadn’t been able to seed grass between the plots, yet.

But weeding twice during the season pretty much took care of the weeds in treatment B. Treatment A was also weeded twice, but as you saw in the graph earlier, weed control by the end of the season was not as effective.

Unmulched plot weeded (on the left), and before weeding (on the right)
Treatment A (transplanted in the spring, with no additional weed control) before (right) and after (left) hand weeding on July 6.

I think we’ll have to wait until next year to really understand how weed control is working in treatment C. Remember, the strategy was to slowly deplete the annual weed seedbank by allowing weeds to germinate, but preventing them from producing more seed. This is not supposed to be a quick establishment method, and it wasn’t.

blooming yellow flower (partridge pea)
This is what partridge pea looks like. It was one of the few species from the native wildflower and grass mix seeded in the spring (treatment C) that bloomed during this first growing season.

Buckwheat as a weed-smothering cover crop

By the time Bryan did our weed assessment, it had been 3 weeks since we mowed the second planting of buckwheat. Ideally, we would have transplanted shortly after mowing the buckwheat. But, the second crop of buckwheat was starting to set seed by the end of August, and our transplants weren’t scheduled to arrive until the end of September. So we mowed the buckwheat early to prevent it from contributing its own seed to the weed seedbank. But this meant that a lot of weeds had time to germinate before we transplanted the habitat plants. The buckwheat certainly suppressed a lot of weeds during the growing season, and I hope that this will help reduce weeds next year.

very young buckwheat seedlings in upper left, larger buckwheat seedlings in upper right, mowing mature buckwheat plants in lower left, cut buckwheat stubble in lower right
The buckwheat established quickly and crowded out many weeds. We mowed the first crop in July and re-planted. We had to mow the second crop about 3 weeks before we transplanted habitat plants (not ideal).

Solarization

Overall, we were pleased with how the solarization worked. We laid down 6 mil clear plastic (leftover from a nearby high tunnel) in early June, and did a little weed control around the edges of the plastic just once during the summer to prevent more weed seed production and to prevent shading of the plots.

Two people shovelling soil on top of clear plastic laid on the ground on the left, and on the right, clear plastic cover a small area of soil, with all the edges of the plastic buried
We laid 6 mil clear plastic over some plots on June 5, 2018 to solarize the soil underneath (and kill weeds).

We also learned that solarization will not control purselane. In contrast, the purselane thrived only under our clear plastic, and nowhere else in the field. The plot that had the most purselane also had the most other (mostly grass) weeds. I think the purselane pushed the plastic away from the soil and reduced the temperature a bit, allowing other weeds to grow.

clear plastic covering a small area of soil, but with weeds (purselane) growing underneath it
In some solarized plots, purselane grew happily under the plastic. Purselane was not a common weed anywhere else in the field during the season.

Some other plots were virtually weed-free when we pulled the plastic up in October. (Did you see how large the error bar was for weeds in treatment F in the weed graph above? This means there was a lot of variability between plots in this treatment.) Our soil temperature probe happened to be in the plot with the most purselane, and we still achieved maximum soil temperatures of 120 °F (at a depth of about 3 inches), compared to 90 °F in a nearby control (treatment E) plot.

Plots of ground that had been covered with clear plastic. On the left, very few weeds grew underneath. On the right, more weeds (purselane and some grasses) grew.
Solarization results were pretty variable from plot to plot. In some plots, it worked great (left). In other plots more purselane germinated and it didn’t work as well (right). We cut all the weedy vegetation off at the ground before direct seeding the beneficial habitat plants.

Repeated herbicide and tillage

At the weed assessment in September, the plot that had been alternately treated with herbicide and tilled looked best in terms of weed control. Like treatment C and all the treatments planted (by seed or by transplant) in the fall, I think we’ll get a better idea next year of how effective this method was at suppressing weeds.

A small plot of mostly bare soil with a few small weeds growing through. The plot is surrounded by grass
A few weeds were present a week after the last time the herbicide/tillage treatment (G) was rototilled. We broadcast, raked, and pressed beneficial habitat seed into these plots.

Timing of fall planting

One thing we struggled with this fall was deciding when to plant the wildflower and grass seed mixture. One source recommended the seeds be planted sometime between October and December. We were cautioned that if we planted the seed too early, some species (especially blackeyed Susans) might germinate this fall, and the young seedlings would be killed by an early frost before they established. But we were also afraid of waiting too long and not being able to till the soil (treatment G, only) if it got too wet. And we wanted a nice smooth seedbed. In treatment F, we suspected that leaving the clear plastic on into November would protect the weeds from the cooler weather. But we worried that taking it off too early would only allow more weed seeds to blow onto the bare ground.

person dressed in warm clothes sprinkling seed on bare ground. There is a field and a pond in the background.
We direct seeded October 18, 2018, after the weather cooled down a bit, and before the ground got too wet.

Finally, we compromised and planted the seeds on October 18 and 19, after our first hard frost, and once it looked like the nighttime temperatures would be in the 40’s (or below) for the next 10 days. It was only a week after the last tillage in treatment G, and the soil was still relatively dry. Those who live in the Finger Lakes know that late October and early November were pretty wet this year, so I’m glad we planted when we did. If you are trying to time fall seeding, I would recommend that you keep an eye on the 10 day forecast to see when temperatures are starting to cool. But if you get a dry sunny day to plant and it’s reasonably cool, I wouldn’t delay.

So if I want to plant habitat for pollinators and natural enemies next year, what should I do?

First, think about the time, money, and equipment you have available, as well as the area you’d like to plant. There probably isn’t a single right way to establish this habitat, but there may be a best way for you.

You can find more details on the techniques we used (and some links to other resources) here.

This post was written by Amara Dunn, Brian Eshenaur, and Betsy Lamb.

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets

Creating habitat for beneficial insects – early summer 2018 project update

Betsy, Deb, and Brian transplanting native wildflowers and grasses that will provide habitat for beneficial insects
Dr. Betsy Lamb, Deb Marvin, and Brian Eshenaur (left to right) transplanting native wildflowers and grasses on the edge of a research Christmas tree planting at Cornell AgriTech in Geneva, NY. These plants will provide food and shelter for pollinators and natural enemies of pests.

As I mentioned in my January post, I am excited to be working with two NYS IPM colleagues (Dr. Betsy Lamb and Brian Eshenaur) to demonstrate the costs, labor, and effectiveness of different methods for establishing habitat plants for pollinators and other beneficial insects. Remember, habitat for pollinators is also habitat for insects and mites that are natural enemies of pests on your farm or in your garden. Thus, planting for pollinators enables you to practice conservation biocontrol. These demonstration plots are located around a new research planting of Christmas trees at Cornell AgriTech at the New York State Agricultural Experiment Station in Geneva, NY. What we learn from this project can help you choose the best way to establish your own beneficial habitat (on your farm, around your home, near your school, etc.)

We are comparing 6 different methods of establishing habitat for beneficial insects, plus a control (Treatment E). Treatment E plots were sprayed with herbicide last fall and this spring, and will be mowed once this year. A summary of the plan for the other treatments is below.

List of treatments in this study. Each treatment is a different method for establishing habitat for beneficial insects
Comparing different methods for establishing plants that provide habitat and food for beneficial insects (pollinators and natural enemies of pests). Treatment E is the control.
seeds for plants that will provide habitat for beneficial insects
Native wildflower and grass seeds (A) were mixed with boiled rice hulls (B) to make them easier to broadcast (C). Much of what you see on the soil surface is just the rice hulls, but there are a few seeds that will hopefully grow into habitat for beneficial insects.

Because of when spring tillage occurred, plots that were scheduled to be tilled in the spring did not need a second herbicide application. About a week after spring tillage, Treatment C plots were direct seeded. I hand-broadcast a mixture of native wildflower and grass seeds at a rate of half a pound per 1,000 square feet. This worked out to be 26 g of seed for each 5-foot by 23-foot plot. To make it easier to broadcast such a small amount of seed, I first mixed the seed for each plot with about 3 cups of boiled rice hulls. After raking the seed in gently with a garden rake, I stomped the seed into the ground to ensure good contact with the soil. In a larger plot, you might use equipment like a cultipacker or lawn roller to achieve the same result.

 

young buckwheat plants
Two weeks (and three-quarters of an inch of rain) after seeding, buckwheat is establishing. It will hopefully crowd out weeds that would otherwise grow in these plots over the summer.

I broadcast (again, by hand) buckwheat seeds in the Treatment D plots at a rate of 70 pounds per acre (84 g for each of these small plots), and raked them in on May 31st. If the buckwheat establishes well, it will smother weeds during the summer, and we can mow and transplant into these plots in the fall. We plan to mow this crop of buckwheat when it starts flowering and then reseed it, for a total of two buckwheat plantings this summer.

 

We transplanted by hand 15 species of wildflowers and 1 grass species into plots assigned to Treatments A and B on June 4th. Because we were able to transplant right after it rained, it wasn’t too difficult to plant into the untilled plots (Treatment A). Some of them still had some stubble from the cover crops and weeds that had been growing in this field last year, and were killed by fall and spring herbicide applications.

Young wildflower and grass plants transplanted into untilled soil.
Native wildflowers and grasses transplanted into untilled soil. Some dead weeds and cover crop still remain on the soil surface.

The day after we transplanted into Treatment B plots, we mulched the plants to a depth of about 3 inches to (hopefully) control weeds for the rest of the summer while the habitat plants get established. We used chips from shrub willow because they were available, but other types of mulch would work, too.

wildflower and grass plants surrounded by mulch for weed control
These wildflowers and grasses will have help out-competing weeds from 3 inches of willow chip mulch.

Finally, we laid clear high tunnel plastic over the plots receiving Treatment F. Ongoing research from the University of Maine suggests that soil solarization can be an effective form of weed control, even in the northeast. So we’re giving it a try! To maximize the efficacy of this technique, we laid the plastic when the soil had been tilled relatively recently, and was still very moist. To keep the plastic firmly in place for the whole summer, we rolled the edges and buried them 4-5 inches deep, then stomped the soil down around all the edges. In the fall, we will hand broadcast a mixture of native wildflower and grass seeds over these plots (same mix as Treatment C).

a trench being dug around the edge of a plot to bury the edge of a sheet of clear plastic
Deb Marvin and Brian Eshenaur (left to right) dig a trench to bury the edge of this sheet of clear plastic. The goal is weed control by soil solarization.

We’ll give weed seeds in the Treatment G plots a few more weeks to germinate and grow (depending on the rain). Then we’ll kill them with an herbicide, and till these plots again to induce more weed seeds to germinate. Then we will repeat the herbicide application, till again, and so on. This should reduce the weed seed bank in the soil over the course of the summer. After a final tillage in the fall, we will broadcast seed from the same wildflower and grass mix we used for Treatment C. Fall is the recommended time for direct seeding beneficial insect habitat in the northeast. This treatment will also have the advantage of a full season of weed control prior to planting (also recommended). The downside is that it will take longer to establish the beneficial insect habitat.

As we get these plots established, we’re keeping track of the time spent on each treatment and the costs of materials. In the late summer or fall, Dr. Bryan Brown will assess weeds in each treatment, and I will photo document how well our beneficial insect habitat plants have established in each plot. All of these data will help you choose the method that fits your timeline, budget, and equipment/labor availability. Stay tuned for more updates…including an invitation to a field day (not this year), so that you can come see the results of this project for yourself!

 

This work is supported by:

  • Crop Protection and Pest Management -Extension Implementation Program Area grant no. 2017-70006-27142/project accession no. 1014000, from the USDA National Institute of Food and Agriculture.
  • New York State Department of Agriculture and Markets