Tag Archives: Christmas trees

Harvesting and sowing your own native seeds – August 17, 2023

Pink echinacea and bright yellow goldenrod flowers
Echinacea and goldenrod are just two species of native perennial wildflowers that feed beneficial insects.

For the past six years, we’ve been cultivating perennial grasses and wildflowers that feed and support beneficial insects. All of these plants came from seeds—whether sown by us or by others—and we’ll focus this year’s annual open house on these wonderful seeds.

Come join folks from New York State Integrated Pest Management, and Petra Page-Mann from Fruition Seeds to talk about how we harvest, clean, store, and germinate seeds of perennial wildflowers that support beneficial insects. Stop by our open house between 3:30 and 6:30 p.m on Thursday, August 17. We’ll offer guided explorations of our established plots of perennial wildflowers and grasses at 3:45, 4:45, and 5:45 p.m. You are also welcome to explore the field on your own, or browse our interactive resources on display. There will be a few hard copies of resources available at the event, and we’ll continue to add digital resources to this folder up to and following the event. Everyone will go home with seeds of native perennial plants that support beneficial insects.

No registration needed for this free event. Find all the details at our event page. When you arrive at the entrance to the farm, look for signs with the pink echinacea flower and the Christmas tree on them, and follow the signs to our field.

Graphic of pink echinacea flower, Christmas tree, and the NYSIPM logo
Follow these signs to find our field!

Funds for this project were provided by NYS Dept of Ag and Markets and the USDA National Institute of Food and Ag.

Protect Pollinators and Natural Enemies of Pests, Choose Pesticides Carefully

A bumble bee and a smaller bee resting on a magenta cosmos covered with tiny water droplets
These bees are just two of the beneficial insects you’ll want to protect from pesticides.

Hopefully we can all agree that protecting friendly insects (pollinators and natural enemies of pests) on our farms and in our gardens and landscapes is important. We want to manage pests, without hurting bees, butterflies, ladybugs, parasitoid wasps, minute pirate bugs, hover flies, ground beetles, and so many more of our insect friends. Using IPM tools other than pesticides is a great way to do this. When it is necessary to use pesticides as an IPM tool, how do you choose a pesticide – whether it is organic, conventional, or biological – that poses the least risk?

Practices that help reduce risk to beneficial insects

No matter how hazardous or toxic any substance is, insects are only at risk if they are exposed to that substance. By using integrated pest management practices like crop rotation, sanitation, and scouting for pests, you can reduce the number of pesticide applications needed to manage pests. Making fewer pesticide applications is a great way to start protecting beneficial insects. Some pesticides are particularly dangerous to insects because they linger so long in the environment after they are applied (have a long residual), posing a greater risk. Other pesticides quickly break down in the environment after being applied to plants, so they pose less risk.

Bee pollinating a cucurbit flower
Wild bees are important pollinators of cucurbit flowers. We can thank them for many of our pumpkins, squashes, cucumbers, and melons.

Being careful about when you apply a pesticide can also reduce the likelihood that a beneficial insect will be exposed to it. Bees are less active at certain times of day (especially early morning and evening). However, some wild bee species forage at different times of day. For example, squash bees are early risers, and can be found visiting squash, pumpkin, and cucumber flowers before honey or bumble bees are active. Check the area where you plan to apply a pesticide, and pick a different time if bees are present. Some pesticide labels require that you do not apply that product while bees are foraging. Some pesticides will still harm bees that visit a flower some time after the pesticide is applied. Avoiding pesticide applications when plants are flowering will provide additional protection to beneficial insects, but may not be practical on all crops.

Where you apply pesticides also matters. Have you planted some habitat for beneficial insects? Prevent pesticide spray drift into these habitats. Are there flowers blooming amongst the grass on the orchard floor? Mowing them before you spray the fruit trees overhead could make insects less likely to visit during or right after you spray.

Resources to consult

First, read the pesticide label (and follow it). The label is the law and will have instructions on how to protect pollinators and other non-target organisms when using a pesticide.

If you know the pesticides you are considering, and especially if you know the specific natural enemies you are trying to protect, you can find some good information from companies that sell beneficial insects, or pesticides. I am aware of searchable databases or charts describing pesticide compatibility from four companies that sell (mostly) arthropod and nematode natural enemies: Agrobio, Biobest, BioWorks, and Koppert.

EIQ stands for Environmental Impact Quotient. You can read more details on the NYSIPM website, but in a nutshell the EIQ quantifies the risks of pesticides. You can use the EIQ calculator on our website to compare these numbers for different pesticides at the rates you plan to use them. The higher the number, the higher the risk. There are different components to the EIQ; risks to consumers, workers, and the environment (ecological). The ecological risk includes risks to natural enemies (as well as fish, birds, and bees). The EIQ calculator will give you an overall EIQ value as well as values for each category of risk (consumers, workers, ecological). Or, you can download this spreadsheet of EIQ values for pesticides, and sort by values for bees or beneficials (columns P and Q).

The University of California IPM Program’s pesticide active ingredients database summarizes the toxicity of some pesticides (including insecticides) to natural enemies and pollinators, as well as other hazards.

The Cornell Pollinator Network produces Pollinator Protection Guides for an increasing number of crop groups to help you understand the toxicity of different pesticide active ingredients to bees.

orange and black-striped fly with large eyes perches on small white flowers
Larvae (maggots) of this hover fly are excellent aphid predators. Killing your hover flies with pesticides could contribute to an aphid outbreak.

A few pesticides to avoid

You’re using good IPM, and you still need to use an insecticide. You’re trying to choose. I used information I collected from a few different sources (listed at the end of this post) to categorize some insecticides as “most” or “moderately” harmful. These are not exhaustive lists.

Most harmful to beneficial insects:

  • Carbaryl – active ingredient found in some products called Sevin
  • Neonicotinoids – active ingredients include imidacloprid, acetamiprid, thiamethoxam and may be found in such products as Admire, Assail, and Actara; In NY many products with these active ingredients are now classified as restricted use, so only certified pesticide applicators are allowed to buy or use them.
  • Natural pyrethrins – PyGanic is one product with this active ingredient; similar to synthetic pyrethroids, but this active ingredient degrades quickly in the environment (short residual)
  • Synthetic pyrethroids – active ingredients include bifenthrin, cypermethrin, lambda-cyhalothrin, permethrin, and others; can be found in products called Sevin, Eight, Warrior, and others; similar to natural pyrethrins, but last much longer in the environment (long residual)
  • Spinetoram – Radiant is one product that contains this active ingredient; a synthetic version of spinosad, but more toxic to beneficial insects than spinosad

Moderately harmful to beneficial insects:

  • Azadirachtin – active ingredient found in products such as Aza-Direct, Azaguard, Neemix
  • Bifenazate – active ingredient found in products such as Acramite
  • Chlorantraniliprole – active ingredient found in Coragen; among natural enemies, parasitoid wasps are probably most at risk. There may be some synergistic effects on bees when combined with other pesticides (see Cornell Pollinator Protection Guides)
  • Indoxacarb – active ingredient found in products such as Avaunt
  • Insecticidal soaps – active ingredient is potassium salts of fatty acids and can be found in M-Pede and many other products; most harmful to soft-bodied insects (including predatory mites), while beetles may be less susceptible
  • Spinosad – active ingredient in Entrust; similar to spinetoram, but it is the natural version of this chemical; not as toxic to beneficial insects as spinetoram

So what are the alternatives?

Remember that pesticides, by definition, are toxic to some living things; that’s why they kill and repel pests. There is no such thing as a completely safe pesticide. But here are a few insecticides that are gentlest on beneficial insects. And let me reiterate: Reducing the use of pesticides through good IPM is the best way to protect insects from pesticides.

  • Beauveria bassiana – several strains of this fungus are active ingredients in different insecticides, including BotaniGard
  • Bt or Bacillus thuringiensis – bacterial active ingredient in pesticides such as Agree, Dipel, and others; quite specific to the insect groups specified on the label; different subspecies are effective against different groups of insects
  • Flonicamid – active ingredient in Beleaf
  • Horticultural oils – there are many different active ingredients that fall in this group; may be more toxic to bees than to natural enemies, but require direct contact with the insect
  • Cordyceps (formerly Isaria or Paecilomyces) fumosorosea – another fungal active ingredient found in products such as PFR-97
  • Clarified hydrophobic neem oil – Note that “whole” neem oil contains azadirachtin (which I listed in the “moderately harmful group”), while clarified hydrophobic neem oil does not. Azadirachtin is extracted from neem oil, leaving the clarified hydrophobic neem oil behind.
Small insect with a black and white diamond pattern on its back on a sunflower petal
This cute little insect is a minute pirate bug. In addition to munching on pollen, it will also eat small pests like thrips, mites, and small caterpillars.

A few reminders…

  • Remember that the information in this post is not a substitute for a pesticide label. The label is the law, and you must read and follow the label of any pesticide you are using. Laws and labels change. It is your responsibility to use pesticides legally. Trade or company names used here are for convenience and information only; no endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.
  • For questions about pesticide use, regulations, and safety, contact the Cornell Cooperative Extension Pesticide Safety Education Program. If you live in New York State, you can find labels for pesticides that are registered in NY at the DEC’s NYSPAD website.
  • Just because a pesticide isn’t on the “most” or “moderately” harmful lists above, does not mean it is harmless to insects. These lists are not exhaustive, and for some products insufficient information exists.

  Sources consulted:

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. Special thanks to Diana Obregon Corredor for providing review and input.

This work is supported by NYS Departments of Environmental Conservation and Agriculture and Markets.

Some great biocontrol events coming up!

Next week is full of great biocontrol events! If you are in the Geneva, NY area, don’t miss out!

Thursday August 11 5:30-7:30 PM

wildflowers growing in a field in the foreground, people standing and talking in the background
Participants enjoying last year’s Habitat for Beneficial Insects Open House.

We are in our 5th year of establishing perennial wildflowers and grasses to support pollinators and natural enemies of pests. Perhaps you’ve been following our progress (although admittedly I owe you all an update post or two). Or maybe you keep up with pictures on my Instagram. Now you can see these plots for yourself at our Habitat for Beneficial Insects Open House!

Come visit us any time between 5:30 and 7:30 PM. This outdoor event is free and no registration is required. Just put this address into your GPS:

1097 County Rd. 4
Geneva, NY 14456

Then look for these signs:

New York State IPM logo next to diagrams of a pink echinacea flower and a green Christmas tree

Funds for this project were provided by NYS Dept of Ag and Markets, the Towards Sustainability Foundation, and the USDA National Institute of Food and Ag.

 

Friday August 12, 5-7:30 PM

Researcher points to labeled rows of Christmas trees growing in a field, while meeting attendees watch
Bryan Brown talking about integrated weed management at last year’s event.

As part of a larger Christmas tree IPM project, we’re looking at using biopesticides applied to Christmas tree roots at planting to protect the young trees from root diseases (especially Phytophthora). We’re having a Field Day so that you can see both acres of Christmas trees we’ve planted and learn about early results from the project.

Please do register for this event using the “Field Day” link above!

Like the Habitat for Beneficial Insect Open House, put this address into your GPS:

1097 County Rd. 4
Geneva, NY 14456

Then look for these signs:

New York State IPM logo next to diagrams of a pink echinacea flower and a green Christmas tree

This work is supported by Agriculture and Food Research Initiative – Foundational and Applied Science Grant no. 2021-68008-34179/project accession no. 1025660  from the USDA National Institute of Food and Agriculture.

 

Saturday August 13, 10 AM – 3 PM

raised bed with wildflowers growing in it
This year we planted two new raised beds with perennials that support beneficial insects.

NYS IPM will be at Cornell AgriTech’s 140th Anniversary Open House talking about how to “feed your insect friends”…by creating excellent habitat for them, of course! This spring we planted two raised beds with a mixture of perennials selected to provide pollen and nectar from spring through fall. Come see how these new plantings are growing, learn more about beneficial insects and how to create your own habitat, and pick up some (temporary) tattoos of pest natural enemies! Then visit the rest of the educational displays at Cornell AgriTech.

Funding for our displays at this event is being provided by Cornell AgriTech and NYS Dept of Environmental Conservation.

IPM for establishing Christmas trees: Survival and growth in the first season

Rows of small Christmas trees growing in a field on a sunny afternoon; some are surrounded by wood chip mulch, some by cultivated ground, some by bare ground, and some by tall weeds.
The different weed management strategies we are comparing certainly look different in the field. But how do they impact tree growth and quality?

Back in June we introduced you to a new project comparing different methods for weed and root disease management when establishing Christmas tree seedlings. Recall that this is a collaboration among Bryan Brown, Amara Dunn, Brian Eshenaur, Betsy Lamb, and Lynn Sosnoskie. We wrapped up our first season in October, and we have a first look at some of the data. In this post, we’ll focus on tree survival and tree growth. There’s a lot more weed data!

Treatments

Let’s start with a quick reminder of the treatments we were comparing. Each row of 28 trees received the same weed management treatment. Each row was also divided into four plots of seven trees each. Each plot within a row received a different root treatment. Here’s a map of how the treatments were laid out in the field.

Weed management (in-row, within a 30” band around the row of trees; between row zones were seeded with grass and mowed 4 times) :

  • Cultivate – three times early in the season using a tractor drawn KULT Kress Argus Toolbar with sweeps, finger weeders, and a rear side-shift adjustment
  • Herbicide – conventional active ingredients (oxyfluorfen and pendimethalin applied shortly after planting, with a fall application of glyphosate) as a control treatment
  • Mow – mow about every two weeks with a walk-behind mower
  • Mulch – 3 inches of chipped shrub willow mulch
  • Untreated – No weed management at all

Root disease management:

  • ProPhyt (active ingredient: potassium phosphite) – a biopesticide applied by dipping bare roots of seedlings just before planting; mixed 1.28 fl oz in 2 gallons of water for 140 trees (11 fl oz/A if you plant 1,200 trees/A)
  • RootShield PLUS WP (active ingredient: Trichoderma harzianum Rifai strain T-22 and Trichoderma virens strain G-41) – a biopesticide applied twice (the day after planting and 7 weeks later) as a drench around each tree (24 oz/A in 171 gallons of water/A)
  • Subdue Maxx – a conventional fungicide applied twice (the day after planting and 5 months later) as a soil-directed spray (2.5 pt/A in 140 gal/A in a 6-inch band on either side of the row of trees). We made the application with a hand-pump backpack sprayer fitted with a TeeJet TTI11005 nozzle with a shield rotated parallel to the row of trees. The maximum pressure possible with this sprayer is 60 psi. After application, we applied an extra 0.45 gallon of water per plot of 7 trees with the same sprayer (280 gal/A additional water).
  • Water – 1 pt of water poured around each tree at planting, as a control.

What we measured

We’re interested in how the weed and root disease treatments impact survival, growth, and quality of these trees. Thanks to our excellent technicians, Marcus and Erik, for helping us measure all of these trees! Betsy and Amara were helping, too, but in this picture Amara is behind the camera.

A woman in a pink shirt comparing a small Christmas tree to a piece of paper, while a man in a plaid shirt measures the height of a small Christmas tree seedling; both are in a newly planted field with freshly tilled soil
Betsy and Marcus measuring trees and evaluating needle color in May.

On May 25 (about a week after planting) and again on October 6 we measured the height of each tree (from the soil to the tallest part of the tree, even if it wasn’t the leader anymore) and the diameter of the tree trunk 4 inches above the soil. In both May and October, we also rated the color of the needles using this scale. However, we only used: 2 (darkest green), 5 (medium green), 7 (paler green), and 9 (yellow or brown).

Of course, measuring and rating each tree also allowed us to take note of which trees had died (versus a few that unfortunately succumbed to “mower blight”).

What we found

Bar graph showing that trees generally survived better when treated with ProPhyt, except not if weeds were managed with herbicide. The impact of root treatment varied, depending on which weed management strategy was used.
Percentage of trees in each plot (out of seven trees total) that were still alive by October 2021, not counting a couple that were accidentally mowed. Each bar is the average of four plots for each combination of root treatment (color of bars) and weed management strategy (along x-axis). The lines on each bar show variability (one standard error above and below the mean value).

It’s too early to know for sure, but it’s possible that the root treatment that results in the best seedling survival might depend on which weed management strategy you use. For example, after just one year, the RootShield PLUS-treated trees did better than the ProPhyt-treated trees where herbicide was used, but not where the weeds were allowed to grow unchecked (‘Untreated’). We haven’t done a statistical analysis on the data, yet, but the little lines at the top of each bar are an indication of the amount of variability amongst the four plots in each treatment (one standard error above and below the mean percent survival, for those who might be interested).

Bar graph showing that trees might have grown slightly more when weeds were managed with herbicides. The impact of root treatment varied, depending on which weed management strategy was used.
Change in height of Christmas trees from May to October 2021. Each bar is the average of up to 28 trees (7 trees in each of 4 plots) for each combination of root treatment (color of bars) and weed management strategy (along x-axis). The lines on each bar show variability (one standard error above and below the mean value).

These Fraser fir seedlings grew between 1 and 2.5 inches during their first season. Much like the tree survival, the root treatment that produced the most growth wasn’t consistent across all weed management strategies. Results for tree trunk diameter were similar.

Bar graph showing that needle color might be slightly darker in the plots that were treated with herbicide or no weed management. The impact of root treatment varied, depending on which weed management strategy was used.
Average needle color when trees were rated in October. Lower numbers indicate darker green color. Each bar is the median value of up to 28 trees (7 trees in each of 4 plots) for each combination of root treatment (color of bars) and weed management strategy (along x-axis).

Recall that needle color was rated as 2 (darkest green), 5, 7, or 9 (most yellow or brown). So on this graph, shorter bars indicate better needle color. Also, this rating scale impacted how we summarized the data. Instead of taking the mean needle rating, we used the median. (Here’s a quick refresher on the difference.) And the graph doesn’t have those little lines to summarize the variability in each treatment. Too early to draw firm conclusions, but again, there might be some interactions between root treatment and weed management strategy.

What does it cost?

Economic risk is one of the risks we seek to reduce through IPM, so we’ve been keeping track of the costs associated with our pest management strategies. Based on the way we applied the root treatments and some local price estimates, here’s what we would have spent per acre for these treatments, assuming we planted 1,200 trees on each acre (that’s 6 ft x 6 ft spacing).

 

Fungicide Rate/A Number of applications Cost/A (Supplies) Cost/A (Labor1)
ProPhyt 11 fl oz2 1 $4 $1,037
RootShield PLUS WP 24 oz3 2 $123 $4,150
Subdue Maxx 2.5 pt3 2 $82 $2,074
Water 1 $0 $2,075

1We assumed a labor rate of $20/hr. These costs were calculated based on the time it took us to apply the products. This includes drenching each tree by hand (RootShield PLUS WP and water) and applying Subdue Maxx (and additional water to move it into the soil) with a backpack sprayer. On a larger scale, there’s surely a more efficient way to do this.

2Seedling roots were dipped in a ProPhyt solution prior to planting. The rate on the label is 4 pt/100 gallons of water. We mixed up 2 gallons of root dip solution (containing 1.28 fl oz of ProPhyt) to treat 140 trees. If we had used a fresh 2 gallons for every set of 140 trees, we would have used 11 fl oz of ProPhyt on an acre of 1,200 trees.

3Because RootShield PLUS WP was applied as a drench to each tree and Subdue Maxx was applied as a soil-directed spray banded on either side of the row, these rates are per acre of ground to which pesticide was applied. This is less than the total space taken up by these trees in the field. Read and follow the pesticide label for instructions on calculating quantity of product needed for banded applications.

And here’s a summary of our weed management costs. You can see all the details of these costs (including labor and supplies) here.

In-row weed management Cost/A (labor and supplies)
Cultivate $248
Herbicide $86
Mulch $1,153*
Mow $293
Untreated $0

*Assumes woodchips can be obtained locally at no cost

Take home

With only one season of data, it’s too early to draw conclusions about the effectiveness (or cost effectiveness) of each treatment. So far, survival of trees treated with ProPhyt is looking very good across most weed management strategies. And we’re seeing some indication that the best (in terms of tree survival, growth, or color) root treatment to use may vary depending on what you’re doing to manage weeds.

In late October we also dug up five dead trees and sent them to the Cornell Diagnostic lab to check for Phytophthora. The trees had been dead for a while, so they were only able to test for the presence of any Phytophthora species (which could include some that don’t cause disease on Christmas trees). Four out of five trees came back positive, which makes us feel more confident that we picked a good field for this trial…if by “good” you mean one where trees will be exposed to Phytophthora. For the purposes of this project, that’s exactly what we mean.

Please let us know if you have questions and stay tuned for more updates on this project. We’ve got at least two more years to go! You can check back on this blog (subscribe so you’ll know when new posts are available!), follow Lynn Sosnoskie and Amara Dunn on Twitter or on Instagram (@specialtycropweedscience and @biocontrol.nysipm), or check out Bryan Brown’s webpage. We’ll also be hosting another field event in 2022 and hope to provide updates at future Christmas Tree Farmers Association of NY meetings.

USDA logo, accompanied by the words: National Institute of Food and Agriculture, U.S. Department of Agriculture

This work is supported by Agriculture and Food Research Initiative – Foundational and Applied Science Grant no. 2021-68008-34179/project accession no. 1025660  from the USDA National Institute of Food and Agriculture.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program, with helpful input from project collaborators. All images are hers, unless otherwise noted.

Know your friends…on the ground

Small clump of blue-green grass surrounded by some bare ground and weeds
We may not spend a lot of time looking at the ground, but there are plenty of friendly insects living at the soil surface and taking shelter in plants like this little bluestem grass that don’t produce pollen-rich flowers, but still support beneficial insects.

In August I wrote about some of the friendly insects that might be visiting your garden this summer. I promised to write more about the natural enemies of pests that you might find at ground level. That time has come! Because these insects (and some other arthropods) live at or near the soil surface, you’re much less likely to see them, unless you happen to be cleaning out a garden bed this fall (which is not actually recommended). Also, they may be more active at night. But they are still doing lots of good things in your garden or on your farm, so they’re worth knowing about.

Rove beetles

Black beetle with a long segmented abdomen that protrudes beyond the short wing covers that look like a cape.
Rove beetles have wing covers that are much shorter than the rest of their body. Image courtesy of Joseph Berger, Bugwood.org.

These beetles live in the soil or at the soil surface and they eat lots of different soil invertebrates, including pests like slugs, snails, thrips, and eggs of other insects. They also eat seeds, so they could help reduce your weed seed bank, too. Like other beetles, they have hard covers over their wings called elytra. Because these covers are much shorter than their bodies, I think it makes them look like they are wearing little capes.

 

Carabid beetles

Black beetle crawling on the ground
Ground beetles may not look very exciting, but they’re great predators to have in fields and yards. Image courtesy of Mary C Legg, Bugwood.org.

Also called ground beetles, this large group of insects mostly live on the ground, and tend to have prominent jaws and move very fast. Their speed makes them great predators of many insects, as well as snails and slugs. Depending on the species, they may also eat seeds. They like to spend the winter in sheltered places including perennial grasses that grow in clumps. In the spring, they can travel almost 200 feet from these grassy shelters (Landis et al. 2000. Annual Review of Entomology 45:175-201). They come in different sizes, but tend to be darker colored.

On the left a black ground beetle with large jaws, and on the right a ground beetle with large jaws that is brown on top of its body and iridescent green on the underside of its body
Just a few more examples of ground beetles, because they’re so cool!

Centipedes

brown centipede with one pair of legs per body segment
Centipedes may not be so pretty to look at, but they’re good predators to have around. Image courtesy of Joseph Berger, Bugwood.org.

They may not look as friendly as lady beetles, but centipedes are also generalist predators that eat lots of invertebrates (including pests) in the soil. In case you were wondering, the difference between a centipede and a millipede is that centipedes have only two legs (one pair) on each segment of their body, while millipedes have four legs (two pairs) per body segment. But they can move pretty quickly, so it’s understandable if you don’t have time to count.

Spiders and harvestmen

From left to right – black and yellow spider, cream-colored spider on a red flower eating a bee, brown daddy long legs on green foliage.
These are just a few of the eight-legged friends you might find in your garden or fields. Some species you’re more likely to find on plants, and others spend more time on the ground.

I wrote about spiders in my previous post, but many species live on or near the ground. Both are good predators, and friends you’d like to have in your fields or garden. Technically, harvestmen (also called daddy long legs) are not spiders, but they do have eight legs. Because they don’t have an obvious “waist” they appear as though their head and body are a single “blob”.

Fireflies

Adult firefly, mostly black with some orange markings
Adult fireflies are more easily recognizable, even when they aren’t lit up. Image courtesy of Whitney Cranshaw, Colorado State University, Bugwood.org.

Yes, you read that correctly. When they are immature, fireflies (or lightening bugs, depending on where you grew up) look a bit more like worms than beetles (which is what they actually are). They live on the ground (especially in places with more moisture) and feed on invertebrates with soft bodies, including both snails and insects. Although we tend to notice them when they are flying, adult fireflies (depending on the species) also spend plenty of time on the ground, and may or may not be predators. The Xerces Society has some really good information about fireflies and their conservation.

immature firefly with distinct body segments. Looks sort of like an armored worm, but with six legs
Immature fireflies may not be so familiar, but are good “friends” because they eat soft-bodied invertebrates, including pests. Image courtesy of Gerald J. Lenhard, Louisiana State University, Bugwood.org.

So remember, not everything that creeps or crawls through your fields or garden is a problem. There are lots of friendly insects (and other arthropods) that can help you with pest control. Take a closer look and you might be surprised!

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

This work is supported by:

  • New York State Department of Agriculture and Markets
  • New York State Department of Environmental Conservation
  • The Towards Sustainability Foundation

Come to our Christmas Tree IPM Field Day!

rows of small Christmas trees growing in a field; trees are surrounded by completely or mostly bare ground, weeds, or mulch
The different weed management treatments are most noticeable, but we’re also comparing at-planting treatments to prevent root disease and improve seedling survival.

You may recall that we started a new project on Christmas tree IPM this year. Now you can come hear more about how the project is going, and see the in-progress treatments in person!

When

The event will be held outdoors on August 19, 2021 from 5:00 to 7:30 PM in Geneva, NY. Please register by August 18th so we have enough food for everyone.

Where

To get to our field, put this address into your GPS:
1097 County Rd. 4
Geneva, NY 14456

Then look for these signs to find our field and park:

New York State IPM logo next to diagrams of a pink echinacea flower and a green Christmas tree

Cost

In order to help improve access to this event, we are inviting attendees to pay what they can. $25 will cover the cost of the meeting, but if this poses a barrier to your attendance, we are suggesting a reduced rate of $15. If you wish to support someone else who might need help attending, you can choose to pay $35. Any questions or concerns, please reach out to me.

Here is the link to pay by credit card.

Here is the link to pay by check or Cornell account # .

Schedule and topics

5:00     Check in

5:30     Introductions and intro to the projects

5:45     Alternative weed management systems for Christmas trees – Dr. Bryan Brown (20 minutes)

6:15     Herbicides for weed management in Christmas trees – Dr. Lynn Sosnoskie (20 minutes)

6:45     Biopesticides for Christmas tree root diseases  – Dr. Amara Dunn (20 minutes)

7:05     Visit the Christmas tree fields and the beneficial habitat project

7:30     Safe travels home

COVID precautions

In order to offer an experience that is accessible and as safe as possible for all attendees, we are requesting that everyone wear a mask unless you maintain at least 6 feet of distance between yourself and people you do not live with, regardless of your vaccination status. There will be plenty of space at the field to spread out (both for eating and drinking, and for participating in the programming). Speakers will be using microphones so that you will still be able to hear even if you are standing further from the speaker than usual. We will have masks available if you do not have one. (But if you have a favorite Christmas tree mask, we definitely want to see it!) These recommendations follow Cornell’s current guidance and if that guidance changes, we will let you know.

More details

  • 1.5 DEC pesticide recertification credits available for categories 1a, 3a, 25 and 10
  • A light supper will be provided.
  • Funds for this project were provided by the Toward Sustainability Fund, NYS Dept of Ag and Markets, and the National Institute of Food and Ag

Introducing a new Christmas tree project

Field with mostly bare ground and small Christmas tree seedlings, each marked by a flag. In the background are some trees and a blue sky with puffy clouds.
We planted a new field of Christmas trees this spring!

If you’ve been following this blog for a bit, you might recall that the beneficial insect habitat plots I’ve been helping to establish and monitor with my colleagues Betsy Lamb and Brian Eshenaur are located on the edges of a field of Christmas trees. Once the trees get a bit bigger, we’ll be able to start assessing whether trees closer to these wildflowers have fewer pests or not.

New in 2021, I’m collaborating with Bryan Brown, Brian Eshenaur, Betsy Lamb, and Lynn Sosnoskie on a three-year project funded by the USDA to look at IPM when you’re establishing a new field of Christmas trees. An important part of IPM is the integration of multiple strategies when managing pests. So in this project we’re looking at some tools for managing both weeds and root diseases (specifically Phytophthora).

Weeds

Our weed management strategies include:

  • Mulching with approximately 3 inches of chipped shrub willow
  • Cultivating three times early in the season using a KULT Kress Argus Toolbar with rear side-shift adjustment pulled by a tractor
  • Mowing grass seeded around the trees
  • Conventional herbicides (oxyfluorfen and pendimethalin applied shortly after planting, with the possibility of additional applications depending on the length of the residual control) as a control treatment
  • No weed management at all (another control treatment)

We planted 560 Fraser firs in 20 rows on May 19th, and four of these rows will be receiving each of these different weed management treatments. So far, we’ve spread mulch…

Four people spreading mulch around small Christmas tree seedlings in a field with rakes or by hand.
Mulch was dumped in small piles along the row of trees, and we raked it in to place. Photo taken by Lynn Sosnoskie.

…and applied herbicides.

Woman in Tyvek suit with backpack sprayer applying herbicides to rows of Christmas tree seedlings. Seedlings receiving herbicide have plastic cylinders around them to protect them.
Since a few of the trees were getting close to budbreak, we shielded them when applying the herbicide.

Lynn and her team collected soil from the field to assess which weed seeds are currently present in the seedbank. They will continue to evaluate the weed seedbank yearly to determine whether different weed management programs result in different weed seeds in the seedbank. Bryan, Lynn, and technicians working for them will also be assessing the success of each weed control strategy throughout the season (weed density and biomass).

Disease

Within each row, plots of seven trees have been assigned to one of four different treatments for root disease control. The biocontrol piece of this project is the root disease management tools. The biofungicide RootShield PLUS WP contains two different species of the fungus Trichoderma. These fungi may protect the trees by:

  • Inducing resistance – turning on the plants defense mechanisms ahead of pathogen attack
  • Exclusion – growing on the roots so there’s no space for the pathogen to grow
  • “Eating” the pathogen – Trichoderma is a fungus that parasitizes other fungi (and water molds)
  • Poisoning the pathogen – Trichoderma produces antimicrobial compounds
  • Promoting plant growth – Stronger, healthier trees are more likely to survive pathogen attack (and probably be more resilient to water stress).

A study done in Oregon on Douglas fir found that Trichoderma species might help improve survival of trees in pots when they are being attacked by the water mold Pythium. So we’re curious if we can document similar results in the field. We applied RootShield PLUS as a soil drench immediately after transplanting, and will repeat the application 6-8 weeks later.

There’s also been some work done by Richard Cowles in Connecticut suggesting that ProPhyt could improve the color of Fraser firs when they are planted in a field known to have Phytophthora. The active ingredient in ProPhyt is potassium phosphite (equivalent to phosphorous acid), so this product is also classified as a biopesticide by the EPA. I think of it as not really a biological control, since it neither contains a (current or formerly) living organism, nor was made by a living organism. We applied ProPhyt as a root dip immediately before planting. It works by inducing plant resistance, and also inhibiting (“poisoning”) water molds like Phytophthora.

The other two root disease treatments are controls: Subdue Maxx (active ingredient mefenoxam) and just water. Subdue Maxx was applied as a shielded, soil-directed spray the day after we transplanted the trees. All the trees were watered in right after planting because we planted a bit late in the season and it was a pretty warm day. The label calls for a second application in the fall.

So far, we’ve collected data on the initial height, stem diameter (4 inches above the soil) and needle color of every tree in the field. We’ll do this again in the fall to assess tree growth over this first season, and tree health (needle color). We will also record how many trees in each treatment survive. Bi-weekly weed surveys have also been initiated. Bryan has started cultivating the trees in that weed control treatment.

Video of Christmas tree cultivation

For updates on this project, you can check back on this blog (subscribe so you’ll know when new posts are available), follow Lynn and Amara on Twitter or on Instagram (@specialtycropweedscience and @biocontrol.nysipm), or listen to Bryan’s podcast. We’ll also be hosting events at the field (Geneva, NY) in this and subsequent years (put August 19th on your calendars, and stay tuned for more details), and hope to provide updates at future Christmas Tree Farmers Association of NY meetings.

USDA logo, accompanied by the words: National Institute of Food and Agriculture, U.S. Department of AgricultureThis work is supported by Agriculture and Food Research Initiative – Foundational and Applied Science Grant no. 2021-68008-34179/project accession no. 1025660  from the USDA National Institute of Food and Agriculture.

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

Creating Habitat for Beneficial Insects: 2020 Growing Season Update

panoramic view of a field with some pink and purple wildflowers blooming in the foreground and rows of small Christmas trees in the background
Trips to our beneficial insect habitat and Christmas tree research plots this year were very solitary, but it was good to get outside.

As many people did, we had to change our plans for this project in response to COVID-19. The biggest change was that we didn’t collect any insects this year. If you follow me on Twitter or Instagram, you saw some pictures of different insects I spotted while visiting these plots this summer. Here are a few highlights:

Composite of images showing a blue dragonfly, several bees (brown and green), a large black and yellow spider, a red ladybug with black spots, a black and yellow striped hover fly, and an orange and black ladybug larva.
Just a few of the cool insects (and one arachnid) I was able to photograph during my weekly visits to the habitat plots.

The Christmas trees are still growing, and Brian Eshenaur and I made sure that the weeds didn’t take over. One Christmas tree grower suggested that they might need some trimming next year. I’m adding “Christmas tree shearing” to the list of new things I will try (learn?) in 2021.

Several smaller Christmas trees growing in a field
Slowly but steadily, the Christmas trees adjacent to our beneficial insect habitat plots are growing!

From May through mid-October, I visited our beneficial insect habitat plots once a week to take pictures and document what was blooming. Brian and I also mowed plots that were direct seeded in fall 2018 twice (May and June). Those of you reading this from NY know how dry much of our summer was, and there really wasn’t a need for more frequent mowing. We decided not to mow Treatment C, which had been direct seeded in spring of 2018. The standard recommendation for establishing perennial wildflowers from seed is to mow for the first two growing seasons, and in the third year to start scaling back on the mowing. Since this was the third season for these spring-seeded plots, we skipped the mowing. I’m not sure we made the right decision for our plots.

Plot of mostly grass and small white asters with a few blackeyed susans and purple coneflowers mixed in.
One plot that was direct seeded in the spring of 2018 and not mowed this year. There were a lot of weeds (some blooming) in addition to some of the species we seeded.

Some of the perennials we seeded bloomed, but mostly these plots were over-run by grass and some weedy asters. It could be that the wildflower establishment was poor. Spring is not the recommended time for planting perennial wildflower seeds. Or it could be that these plots needed to be mowed at least once this season. Since 2021 will be the third year for the fall-seeded plots, I’m wondering about reducing the mowing in these plots, instead of stopping “cold turkey”.

In the meantime, the fall-seeded Treatments F and G (mowed twice in 2020) are developing nicely! Even when there weren’t many flowers, I could recognize lots of wildflower seedlings.

Picture of mixed species plants, with only two yellow flowers. Purple circles and labels identify butterfly milkweed, blackeyed susan, wild bergamot, smooth blue aster, purple coneflower, and coreopsis seedlings.
At first glance, this might look like a patch of weeds, but I’ve learned to spot some of the seedling perennial wildflowers direct seeded in fall 2018.

In July and August, there were abundant blackeyed susan blossoms, and in September and October all four aster species bloomed.

Somewhat weedy plot with lots of blackeyed susan blooms (yellow with dark brown centers); some Christmas trees, grass, and blue sky with puffy clouds are in the background
The fall-seeded habitat plots don’t look manicured like the plots that were transplanted in spring and mulched, but there were a lot of blackeyed susans blooming in mid to late summer this year!
Mixture of seedlings, some with daisy-shaped flowers in various shades of purple
Direct seeded plots contained New England asters (darker purple flowers), zigzag asters (pale flowers, stems grow in zigzag pattern), smooth blue asters (pale purple flowers, smooth leaves and stems), and aromatic asters (more compact growth habit, light purple flowers).

This year, I kept notes not only on what was blooming each week, but on whether blossoms had just started to open (E = early bloom), were fully open (P = peak bloom), or were fading (F = fading bloom). Because there were 12 plots for each transplanted or direct seeded species, if the plots were evenly split between early and peak (E/P) or peak and fading (P/F), I included these two intermediate categories. You can see a color version of the following tables here. The colors give a nice visual of the progression of blooms over the season (including some weeks when there was a bit of a lull in blooms).

E early bloom
E/P evenly mixed early & peak bloom in different plots
P peak bloom
P/F evenly mixed peak & fading bloom in different plots
F fading blooms

When transplanted wildflowers bloomed in 2020

May Jun Jul Aug Sep Oct
5 12 21 27 1 9 16 23 30 6 14 21 28 6 12 17 26 1 8 15 22 28 6 14
Golden alexanders E P P P F F
Ohio spiderwort E E E P P P F F F F F F F F
Catmint E P P P/F F F F F F F F F F F F F F F F F
Lanceleaf coreopsis E P F F F
Blue false indigo E P
Tall white beard tongue E P F F F F
Common milkweed E F
Purple coneflower E E P P P F F F F F F F
Wild bergamot E P/F F F F F F
Anise hyssop E P P F F F F F
Boneset E P P F F F F
NY ironweed E E E P P P P F F
Orange coneflower E E P P P P P/F F F F F
New England aster E E E E P P P F
Showy goldenrod E P P F F

When direct seeded wildflowers bloomed in 2020

May Jun Jul Aug Sep Oct
5 12 21 27 1 9 16 23 30 6 14 21 28 6 12 17 26 1 8 15 22 28 6 14
Golden alexanders E P P/F
Hairy beard tongue E E
Lanceleaf coreopsis E P/F F F F F F E P F F F F F F
Tall white beard tongue E
Blackeyed susan E E P P P P P P P/F P/F F F F F F F
Purple coneflower E E P P P P F F F F F F E/P
Wild bergamot E F F
Butterfly milkweed P F E
Orange coneflower E P P P/F F F
Smooth blue aster E E P P P P
Gray goldenrod E E E/P P F F
New England aster E E P P P
Zigzag aster E E P P P
Aromatic aster E/P E/P P
Yellow false indigo
Partridge pea
Marsh blazing star
Narrowleaf mountainmint
Wild senna
Maryland senna
Early goldenrod
Ohio spiderwort

 

Common name Scientific name
Anise hyssop Agastache foeniculum
Aromatic aster Symphyotrichum oblongifolius
Blackeyed susan Rudbeckia hirta
Blue false indigo Baptisia australis
Boneset Eupatorium perfoliatum
Butterfly milkweed Asclepias tuberosa
Catmint Nepeta faassinii
Common milkweed Asclepias syriaca
Early goldenrod Solidago juncea
Golden alexanders Zizia aurea
Gray goldenrod Solidago nemoralis
Hairy beard tongue Penstemon hirsutus
Lanceleaf coreopsis Coreopsis lanceolata
Marsh blazing star Liatris spicata
Maryland senna Senna marilandica
Narrowleaf mountainmint Pycnanthemum tenuifolium
New England aster Symphyotrichum novae-angliae
NY ironweed Vernonia noveboracensis
Ohio spiderwort Tradescantia ohiensis
Orange coneflower Rudbeckia fulgida va. Fulgida
Partridge pea Chamaecrista fasciculata
Purple coneflower Echinacea purpurea
Showy goldenrod Solidago speciosa
Smooth blue aster Symphyotrichum laeve
Tall white beard tongue Penstemon digitalis
Wild bergamot Monarda fistulosa
Wild senna Senna hebecarpa
Yellow false indigo Baptisia tinctoria
Zigzag aster Symphyotrichum prenanthoides

From the second or third week of May through the second week of October, there was always something blooming in these plots, whether they were transplanted or direct seeded. You can also see that a fair number of species in the seeded plots did not bloom this year. Hopefully next year.

In the meantime, I’ll be making plans for the 2021 growing season, which will hopefully include a return to insect sampling. Stay well and stay safe!

 

This post was written by Amara Dunn, Biocontrol Specialist with the NYSIPM program. All images are hers, unless otherwise noted.

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
  • The Towards Sustainability Foundation

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