It is time to revisit our post on bagworms! Over the weekend, I was notified by the National Phenology Network that bagworm caterpillars will be emerging in our area in the next six days. If you need to treat a tree that has been infested with bagworms in the past, it is important to do so soon after emergence when the caterpillars are small, as treatments are not effective against larger caterpillars.
Have you ever noticed one of these structures hanging on a Colorado blue spruce or an arborvitae? They kind of look like pine cones, but not exactly. Well, they aren’t pine cones, but silken bags spun and decorated by bagworms (Thyridopteryx ephemeraeform).
Bagworms are moths whose larvae feed on evergreens such as spruce, juniper, pine and arborvitae. The larvae can also feed on deciduous trees such as maple, elm, birch and sycamore. Bagworms defoliate the trees and shrubs they infest. In large numbers, bagworms can cause significant defoliation, which can lead to the death of the plant.
Bagworm Lifecycle
In late spring, bagworm eggs, which overwinter in their mother’s silken bag, hatch and caterpillars emerge. These caterpillars begin to form new silk bags, and as they eat, they cover it with bits of leaves. As the caterpillar grows, it expand its bags. Then in late summer the caterpillar firmly attaches its bag to the plant and pupates.
Adult male bagworm
Complete metamorphosis from caterpillar to moth takes about four weeks. Adult male bagworms emerge from their bags as clear winged moths and begin to search for a mate. Adult female bagworms are wingless moths and never leave their bags. After mating females produce 500-1000 eggs before dying. Their eggs overwinter inside their mother’s silken bag and the whole cycle begins again.
Management
Because bagworms are protected by their silken bag, management can be tricky. For smaller trees and shrubs the best tactic is to remove and destroy the bags by hand. Unfortunately, this is not possible in all instances, especially on larger trees and shrubs. Insecticides are most effective right after bagworm eggs hatch, when the caterpillars are small.
But how does one know when the eggs are going to hatch? Well, it turns out that there is a “Bagworm Forecast” that you can check in the spring to determine the best time to apply insecticide. The maps provided by this forecast are updated daily and available six days in the future, so you can plan ahead.
For recommendations on pesticides, check out the resources below. And as always, make sure you read and follow all the instructions on the pesticide label including the use of personal protective equipment. The label is the law!
As females don’t fly, you may wonder how bagworms spread. Bagworm caterpillars can balloon, or use their silk threads to catch the wind and travel long distances.
Despite relatively little protection for overwintering bagworm eggs, research at Purdue University found that it takes a 24 hr period at -0.6 ° F or below to kill the eggs. So if you live in Orange County New York don’t expect a cold winter to kill off your bagworms.
By Cecille Jones, Monroe Master Gardener Volunteer
This article appeared in the August 2021 Issue of Gardening in Orange County.
Did you know one of the smallest insects in the world also happens to be the deadliest to humans? Yup, those pesky mosquitoes renowned for ruining many an outdoor evening event kill more humans every year than sharks, snakes, lions, crocodiles, and hippos combined. Of course they don’t do it alone; mosquitoes do not actually cause diseases themselves but act as vectors (carriers) for deadly diseases such as malaria, encephalitis, dengue fever, yellow fever, West Nile virus and Zika, to name a few. To transmit these diseases, mosquitoes first need to feed on the blood of a human or other animal that is already infected by the disease. Afterwards when they bite a healthy human, they pass on the disease.
Female Mosquito
There are as many as 3,500 species of mosquitoes and they live on every continent except Antarctica. Not all mosquitoes bite, some adult mosquitoes feed exclusively flower nectar. And for the mosquitoes that do bite, less than one hundred species are carriers of horrible diseases. And it is only the female mosquitoes that take a blood meal from hosts like us. And they only do it, because they need the protein from our blood to produce their eggs.
Mosquito larvae (Culex sp.)
So, what are mosquitoes good for, you ask? Mosquito larvae are an integral part of the aquatic ecosystems in which they live. Mosquito larvae that live in wetlands consume a lot of organic matter. By straining organic particles through their system and converting into their own tissue matter they help recycle nutrients back into the ecosystem. Mosquito larvae serve as an important food source for other aquatic animals such as dragonfly larva and fish. From the human point of view, mosquitoes seem to exist to annoy us or make us sick, but from the point of view of spiders, birds, bats, reptiles, amphibians, fish, and other animals that rely on them as a source of food, mosquitoes are important for survival. For example, in the Arctic tundra, birds rely on the swarms of mosquitoes to stay alive.
Mosquitoes are beneficial to plants as well. Many adult mosquitoes depend on plant nectar for their energy, and while retrieving the nectar, they also pollinate plants. And as we know that pollination is key to plant reproduction, mosquitoes play an important role in helping plants survive so they can provide food and shelter for other organisms.
The reality is that not enough is known about all the interspecies interactions of mosquitoes to get rid of them without doing harm to other species in our ecosystems. In the meantime, scientists are studying mosquito saliva in hopes of finding properties that can lead to the development of anti-clotting drugs that can be used to treat cardiovascular disease. Until that day arrives, we may not have a conclusive answer to the question: What are mosquitoes good for?
This article appeared in the July 2021 Issue of Gardening in Orange County.
Basil downy mildew has been a persistent deadly disease of greenhouse and garden basil crops in the US for over 10 years. It is caused by the pathogen Peronospora belbaharii. This fungus-like oomycete can infect the plant during its whole lifecycle from seed to full maturity. Pesto lovers beware since sweet basil (Ocimum basilicum) is the most susceptible.
Signs and Symptoms
Chlorosis of a basil leaf
Usually the first symptom is a non-specific chlorosis or yellowing of the top portion of the lower leaves of the basil plant that then travels up the plant. The discoloration is contained within the borders of the major veins of the leaf. The affected leaves will eventually wilt or curl, die and turn brown. A distinguishing feature of basil downy mildew is the fluffy purplish gray spores that grow on the undersides of the leaves. Unfortunately, infected plants and seeds may not show any signs or symptoms especially if in cool, dry conditions.
Transmission
Downy mildew spores on the bottom of basil leaf
Peronospora belbaharii is primarily spread via wind-borne spores called sporangia. Contaminated seeds, other basil plants, garden tools and gloves are other forms of transmission. The spores thrive in warm, humid and wet conditions but can still infect plants and reproduce in temperatures as low as 59° F.
Basil downy mildew does NOT overwinter here in New York. It can NOT survive in the soil or on dead plant tissue (like many pathogens). Each year spores are carried up from the southern United States by the wind.
Management
Basil downy mildew is difficult to treat once the disease has been established. High temperature steam treatments have shown promise in eradicating the pathogen on basil seeds. There has also been some success in developing disease resistant cultivars for less susceptible varieties of basil such as red leaf, lemon, and spicy basil, but developing disease resistant cultivars of sweet basil has proven more challenging. According to research at Cornell University evaluations the sweet basil cultivars ‘Eleonora’,, ‘Prospera’ and ‘Pesto Besto’ may be some good options.
Since basil downy mildew is an oomyete and not a true fungus, fungicides have limited value and are not recommended for the home gardener. Because basil downy mildew does NOT overwinter in New York, removing crop debris at the end of the season and crop rotation are not helpful for management of basil downy mildew.
Monitoring and cultural practices have been most successful especially in the home garden and greenhouse settings. Monitoring all seedlings and plants for yellowing leaves and gray downy growth is imperative. Once you determine your plant is infected, immediately harvest the unaffected leaves for culinary purposes, and then remove the plant and dispose of it in the garbage.
Basil Downy Mildew Map (July 27, 2021)
The annual spread of basil downy mildew is monitored and confirmed cases are tracked. To have a better idea as to when your plants are likely to become infected, you can follow the spread of basil downy mildew on the ‘Basil – Ag Pest Monitor‘ website and sign-up for alerts.
Reducing leaf wetness can be helpful in preventing infection. Always water basil plants at the base either by hand or using a drip irrigation system. Plant basil in full sun and maximize your spacing between plants to provide good air movement. These practices allow the leaves to dry quickly after rain or dew. If you are growing basil indoors or in a greenhouse, an effective way to increase air circulation and reduce leaf wetness is by directing a fan towards the plants.
If you accidentally eat a piece of basil with downy mildew, don’t worry. Pathogens that cause diseases in plants are different than the pathogens that cause disease in humans. It’s not poisonous to humans and should not cause you any symptoms.
By Kimberly Marshall, Washingtonville Master Gardener Volunteer
This article appeared in the June 2021 Issue of Gardening in Orange County.
Nothing feels worse than seeing your squash wilt and die—especially after months of watching those leafy green beauties thrive in your garden.
Although the culprit may be many things, it often turns out to be the squash vine borer (Melittia cucurbitae)—an odious insect that nestles into the squash’s stem. Whilst making a lovely home for itself, it chokes off the plant’s nutrients and kills those crops you’ve so carefully chosen, planted, and reared.
To prevent the squash vine borer from damaging your harvest, here’s how to recognize and eliminate the pest.
How to identify the squash vine borer and the damage that it does:
Look for
black moths with orangey-red markings on the head, legs, and abdomen
flat eggs resembling tiny brown ovals around the plant’s base
fat, white, wrinkly, worm-like larvae at the base of the stem
wilting leaves and rotting stems
holes at the base surrounded by “frass” (which looks like sawdust)
How to prevent squash vine borers from ruining your yield:
rotate your crops (as borer cocoons overwinter in the soil)
clear away squash plants immediately after harvesting, removing any and all plant debris
use row covers early in the growing season (must be removed to allow for pollination), or protect stem bases by wrapping them in aluminum foil
grow borer-resistant varieties, such as ‘Cocozella di Napoli’ or ‘Costata Romanesco’. Butternut squashes are also highly resistant.
plant extra—just in case.
How to minimize damage if borers have found your garden anyway:
plant the pest’s preferred crop—Hubbard squash—as a ‘trap crop’
fill a yellow dish or bucket with water to attract moths. While this won’t totally divert them from the plants, it will provide an indication of their presence so you know to be extra vigilant about looking for eggs
if you notice frass, immediately cut lengthwise up the squash’s stem, remove all of the larvae, and then bury the cut in nutrient-rich soil to re-root.
In general, you should look for the squash vine borer early and often. After all, it’s always better to be a safe gardener than a sorry one!
By Karen McCarthy, Newburgh Master Gardener Volunteer
This article appeared in the May 2021 Issue of Gardening in Orange County.
Years ago, hiking with friends in Orange County in July, we noticed something was “off.” It was too bright in the forest, and we heard a sound like rain. Looking up, we realized we were in an area infested with gypsy moth caterpillars that had eaten most of the leaves, creating more light than shade. The sound we heard was falling caterpillar excrement. A ruined hike!
The gypsy moth (Lymantria dispar) is native to Europe and was introducedto the United States in 1868 by a French scientist in Massachusetts hoping to breed a silk-spinning caterpillar that was resistant to disease. Some of his moths escaped and are now found as far west as Minnesota and as far south as South Carolina.
The gypsy moth is one of the most important forest pests in our area as the larvae gorge themselves on shrub and tree leaves, leaving them bare and susceptible to disease. They cause millions of dollars of damage every year. They will feed on a wide variety of tree species, but prefer oaks, apples, birches, poplars, and willows.
Lifecycle
Gypsy moths spend most of the year as eggs. These egg masses can contain 500 to 1000 eggs and can be found on trees, firewood, outdoor household items, mobile homes, etc . Depending on the weather, in our area gypsy moth eggs will hatch in late April or early May.
Once the larvae emerge, they begin to move upwards into the canopy of a tree. Some larvae will stay in that tree to complete their lifecycle while others will spin a long silken thread and suspend themselves in the air waiting for a strong wind the carry to another tree; this is know as ‘ballooning.’ Once the ballooning larvae settle on a new host it will begin feeding.
In June or early July, gypsy moth caterpillars will stop feeding and pupate. Two weeks later they will emerge as adults. Male moths are brown with black markings while female moths are white with black markings. Female moths do NOT fly which means that ballooning larvae is one of the most important means of dispersal. Of course humans also play a large role in the dispersal of this invasive species. A great time to remind you: “Don’t Move Fire Wood!” Adult gyps moths do not eat and are only around for about two weeks. Males usually emerge first and wait for the females, who put out a pheromone to attract them. After mating the females lay eggs and then die.
Management
Overwintering egg masses can be scraped off trees and destroyed before they hatch in late April and early May. Young caterpillars,
less than one inch in length, can be killed using the biopesticde Bacillus thuringiensis (Bt). When using any pesticide read and follow all the instructions on the label!
Once caterpillars hatch they climb up the tree in search of food, so tree bands made of duct tape with the sticky side out or another nonporous material smeared with a stick substance can be used to trap them. For a severe infestation you may need to contact a local arborist. Find one at https://www.treesaregood.org/. Repeated annual defoliation can result in the death of a tree.
‘Fun’ Facts
One two-inch gypsy moth caterpillar can consume up to one square foot of foliage every 24 hours.
In places where there are 250 or more egg masses per acre, larvae can defoliate the infested trees.
Ballooning gypsy moth caterpillars can travel up to mile.
In Ohio, where gypsy moths have not yet established themselves throughout the state, they deploy 12,000 gypsy moth traps across the state to monitor movement and evaluate, detect or delineate newly established colonies.
By Gerda Krogslund, Middletown Master Gardener Volunteer
This article appeared in the April 2021 Issue of Gardening in Orange County.
Newly hatched European pine sawfly larvae
In New York State, there are six species of sawflies that are common pests of pines. Sawfly larvae are caterpillar-like and usually feed in groups and strip one branch of needles after another. They prefer old needles, but turn to new needles when food is scarce. The European pine sawfly (Neodiprion sertifer) is one of the most destructive in New York State. It prefers red and Scotch pine, however it will also attack other pines in the area.
Life Cycle
Adult European pine sawfly
Sawfly adults resemble large houseflies but are actually closely related to wasps and sometimes referred to as ‘stingerless wasps.’ Females European pine sawflies have a serrated ovipositor, a tube-like organ used for egg laying, which enables them to saw little slits in the needles to lay their eggs leaving a row of brown scars on the needles. The eggs overwinter and may start to hatch as early as April or as late as mid-May. The larvae feed in colonies for several weeks. When the larvae are fully grown, they drop to the ground and pupate. Then in September adults emerge and mate. Then the females use their saw-like ovipositor to lay 6-8 eggs per pine needle.
Egg scars
Management
When European pine sawfly eggs hatch birds and rodents help decrease the number of larvae on your pines, but sometimes additional management is needed. You can remove larvae by hand or prune out infested branches. Put larvae and branches in a pail of soapy water.
If you chose to use an insecticide, keep in mind that as with most insects, sawflies are more susceptible to insecticides when they are small. There are horticultural oils and insecticidal soap labeled for control of sawflies. If you chose to use an insecticide make sure you read the entire label and follow all of the instructions including the use of personal protective equipment. The label is the law! And remember sawflies are NOT caterpillars so Bt, a go to organic pesticide for many home gardeners, will not work on sawflies.
Fun Facts
Sawfly larvae are often mistaken as caterpillars, but it is quite easy to tell the difference if you know what to look for.
Both caterpillars and sawflies have three sets of true legs (six legs in total). These are located near the head. After the true legs are a series of prolegs. Caterpillars have five or fewer pairs of abdominal prolegs while sawfly larvae have six or more pairs of abdominal prolegs.
European Pine Sawfly Larvae
Look at the picture above. You can see three pairs of true legs. (The first pair is a bit hard to see; it is between the head and the pair of true legs sticking straight up in the air.) After the true legs there is a gap and then seven pairs of abdominal prolegs. There is also a pair of anal prolegs at the very end of the body. Since seven is more than five, this must be a sawfly larvae.
Zebra caterpillar (Melanchra picta)
Look at the picture above. You can see three pairs of true legs right behind the head. Then there is a gap followed by four pairs of abdominal prolegs. There is also a pair of anal prolegs at the very end of the body. Since four is less than five, this must be a caterpillar.
By Cecille Jones, Monroe Master Gardener Volunteer
This article appeared in the December 2020 / January 2021 Issue of Gardening in Orange County.
Varied carpet beetle (Anthrenus verbasci)
Carpet beetles (Family Dermestidae) also know as dermestid beetles are a common household pest. Because they can cause damage to carpets, coats, blankets and even taxidermy mounts, you definitely do not want these pests in your home.
Carpet beetle damage
The damage caused by these pests is often mistaken for that of clothes moths. Watch out for threadbare spots and irregular holes in your wool, fur, felt, silk, feathers and leather items. Cotton and synthetic fabrics such as polyester and rayon are rarely attacked unless they’re blended with wool or are heavily soiled with food stains or body oils.
But we are not done yet, although many species feed on animal based products, there are also several species that are considered pantry pests and will feed on dry food products such as milk powder, spices, seeds, and grains.
Carpet Beetle Lifecycle
Carpet beetle on a flower
Carpet beetles enter your home by hitching rides on cut flowers, clothing or pets. They also can simply fly through open windows and doors. In the springtime, keep an eye on your windowsills – this is where they often appear.
Black Carpet Beetle (Attagenus unicolor)
Once inside your home, female beetles lay between 50 to 100 eggs. In a couple weeks, the eggs hatch into worm like larvae. Larvae measure from ⅛ to ¼ inch long, tan or brownish in color, slow moving and densely covered with hair or bristles.
Furniture Carpet Beetle (Anthrenus flavipes)
The larval stage is the damaging life stage. Many species of carpet beetles feed on things of animal origin (i.e. hide, fur, feathers, leather, wool, dead insects, etc.), while other species are pantry pests and feed on dry food products (i.e. flour, spices, nuts, grains, pasta, cereal, etc.). Depending on the species and the conditions in which they live (i..e. temperature, food source, etc.), they will feed from anywhere between three months and two years, before pupating. A few weeks after pupation, they emerge as adults. The adults are not considered pests and can be found out in your garden eating pollen from various flowers.
Management
To prevent an infestation, dry clean or launder susceptible items before storing them. This will kill eggs or larvae as well as remove odors that attract these pests. Storing susceptible items in air tight containers will also keep these damaging pests away. Routine and thorough vacuuming is helpful in eliminating an infestation. As a supplement to good housekeeping, you can monitor for carpet beetles using baited or non-baited glue traps.
Fun Facts
Carpet beetle larva
Although carpet beetles probably won’t bite you, the hairs on the larvae can cause can cause an allergic reaction producing large, itchy red welts.
Carpet beetles are the bane of many insect collectors as they will feed on dried insect specimens reducing beautifully pinned specimens into a pile of dust.
When preschool and kindergarten students started getting large, itchy welts on their legs, and an investigation determined that the culprit was carpet beetle larvae on the new, natural-fiber carpets that school had purchased for its classrooms.
Have you ever noticed one of these structures hanging on a Colorado blue spruce or an arborvitae? They kind of look like pine cones, but not exactly. Well, they aren’t pine cones, but silken bags spun and decorated by bagworms (Thyridopteryx ephemeraeform).
Bagworms are moths whose larvae feed on evergreens such as spruce, juniper, pine and arborvitae. The larvae can also feed on deciduous trees such as maple, elm, birch and sycamore. Bagworms defoliate the trees and shrubs they infest. In large numbers, bagworms can cause significant defoliation, which can lead to the death of the plant.
Bagworm Lifecycle
In late spring, bagworm eggs, which overwinter in their mother’s silken bag, hatch and caterpillars emerge. These caterpillars begin to form new silk bags, and as they eat, they cover it with bits of leaves. As the caterpillar grows, it expand its bags. Then in late summer the caterpillar firmly attaches its bag to the plant and pupates.
Adult male bagworm
Complete metamorphosis from caterpillar to moth takes about four weeks. Adult male bagworms emerge from their bags as clear winged moths and begin to search for a mate. Adult female bagworms are wingless moths and never leave their bags. After mating females produce 500-1000 eggs before dying. Their eggs overwinter inside their mother’s silken bag and the whole cycle begins again.
Management
Because bagworms are protected by their silken bag, management can be tricky. For smaller trees and shrubs the best tactic is to remove and destroy the bags by hand. Unfortunately, this is not possible in all instances, especially on larger trees and shrubs. Insecticides are most effective right after bagworm eggs hatch, when the caterpillars are small.
But how does one know when the eggs are going to hatch? Well, it turns out that there is a “Bagworm Forecast” that you can check in the spring to determine the best time to apply insecticide. The maps provided by this forecast are updated daily and available six days in the future, so you can plan ahead.
For recommendations on pesticides, check out the resources below. And as always, make sure you read and follow all the instructions on the pesticide label including the use of personal protective equipment. The label is the law!
As females don’t fly, you may wonder how bagworms spread. Bagworm caterpillars can balloon, or use their silk threads to catch the wind and travel long distances.
Despite relatively little protection for overwintering bagworm eggs, research at Purdue University found that it takes a 24 hr period at -0.6 ° F or below to kill the eggs. So if you live in Orange County New York don’t expect a cold winter to kill off your bagworms.
This article appeared in the July 2019 Issue of Gardening in Orange County. Click here to subscribe!
Insects can cause a lot of damage to your plants. Determining what insect is causing damage to your plant is key to developing an effective management strategy. The first step is to examine the damage.
Biting/Chewing Insects
Chewing damage
Biting/chewing insects create holes in plant leaves. The size and shape of these holes varies by insect. The three most common types of insects with biting/chewing mouthparts you may find in your garden are: grasshoppers, butterfly/moth larvae, and beetles (adults and larvae).
Grasshoppers are a sporadic pest and rarely cause substantial damage to garden plants. During dry years when other plants dry out, grasshoppers may seek refuge and food in your lush green garden. Unfortunately, because grasshoppers are highly mobile they are difficult to manage. If you have an ongoing problem with grasshoppers, you can reduce populations, by fall tillage as grasshoppers overwinter as eggs laid in the soil.
Those beautiful white butterflies you see fluttering around your garden, may seem innocuous, but their larvae, the imported cabbageworm, can cause extensive damage to plants in the brassica family also known as cole crops. These plants include broccoli, cabbage, Brussel sprouts, collards, kale, radishes, and turnips. The caterpillar is bright green with a yellow stripe down the center of its back. They start out chewing little holes in the leaves of the plants, but eventually consume the entire leaf leaving only the midrib behind.
Imported cabbageworm damage on cabbage
To monitor for these pests, look for dark green frass or poop near feeding areas. Once you discover a population of imported cabbageworm, depending on how numerous they are you can hand pick them off your plant. The use of Bt (Bacillus thuringensis), a microbial insecticide is also highly effective on younger caterpillars. This particular pest spends the winter in the pupal stage, so to prevent future infestations you can eliminate overwintering sites in your garden by removing plant debris.
Stripped and Spotted CucumberBeetles (Acalymma vittatum and Diabrotica undecimpunctata howardi)
Stripped cucumber beetle
Although they are called cucumber beetles, these insects feed on much more than cucumbers. The stripped cucumber beetle prefers plants in the cucurbit family (squash, pumpkins, melons, etc.) feeding on leaves, flowers, stems and fruits. They can be especially detrimental to young seedlings.
Spotted cucumber beetle / Southern corn rootworm
The spotted cucumber beetle is more of a generalist and feeds on cucurbits as well as beans, tomatoes, and ornamentals. The larvae of this beetle can do substantial damage on the roots of corn plants hence its other name, the southern corn rootworm.
Bacterial wilt of a cucumber plant
Cucumber beetles vector or transmit bacterial wilt (Erwinia tracheiphila), a common disease in cucurbits in which bacteria clog up the vascular system of the plant preventing the flow of water and causing the plant to wilt and eventually die.
One way to protect your plants from cucumber beetles is by using row cover. This can be put on at planting and kept on until female flowers appear, then it must be removed to allow for pollination.
Sucking/Piercing Insects
Squash bug damage on a squash plant
Sucking/piercing insects can cause of variety of symptoms including leaf malformation and leaf discoloration. The most common types of insects with sucking/piercing mouthparts are from the Order Hemiptera, also known as the “true bugs”. This order of insects contains, stink bugs, squash bugs, cicadas, leaf hoppers, scale, aphids and many more.
Brown marmorated stink bug (Halyomorpha halys)
Brown marmorated stink bug adult
Many people are familiar with this invasive species because the adults invade their home every fall looking for a nice warm place to spend the winter. Although it can be an unwelcome house guest it also can cause major damage on fruits and vegetables. Some of the brown marmorated stink bug’s favorite snacks include apples, peppers, beans, tomatoes, and sweet corn.
Brown marmorated stink bug 1st instar nymphs clustered around an egg mass
Controlling the brown marmorated stink bug can be quite difficult because they are highly mobile, feed on a large variety of plants, and adults are highly resistant to insecticides. Monitoring for these pests is the best way to start. Bunches of about 28 eggs are laid on the underside of leaves and should be removed and destroyed if found. When the eggs hatch the 1st instar nymphs cluster around the egg mass making them an easy target for removal. The bugs usually drop down when startled, so for hand removal, you can knock them into a container of soapy water.
Lots of research is being done to develop effective management strategies for brown marmorated stink bug. One of the most promising avenues of research is on biological control. A stingerless wasp known as the Samurai Wasp (Trissolcus japonicas) destroys 60-90% of brown marmorated stink bug egg masses in its native range in Asia. This tiny wasp has found its way to the United States and as of 2018 has been found in twelve states, including New York. Research is now being done to determine the effectiveness of rearing and releasing this tiny parasitoid. Check out this video about brown marmorated stink bug and the samurai wasp.
Potato Leafhopper (Empoasca fabae)
Potato leaf hopper adultPotato leaf hopper nymph
Despite their name, potato leaf hoppers feed on over 200 hundred different kinds of plants including potatoes, snap beans, cucumbers, pumpkins, egg plants, rhubarb, squash and sweet potatoes. The nymphs are neon green and are usually found crawling around on the underside of leaves. The adults only reach ⅛ inch in length. They are pale green and wedge shaped and fly away when disturbed.
Hopper burn on bean leaves
These little pests do not overwinter in our area, but instead overwinter down south and the adults are brought up each year by the winds arriving in late-May / early-June. Although small, a few individuals can cause hopper burn on your plants. Hopper burn reduces yield and is characterized by chlorosis, or yellowing, of the leaf edges. Eventually these leaves begin to curl and turn brown.
It is easiest to combat these pest as flightless nymphs using insecticidal soaps or horticultural oils on the undersides of leaves. Dusting plants with diatomaceous earth can also help deter these pesky bugs.
Squash Bug (Anasa tristis)
Squash bug nymphs
Squash bugs are pests of all cucurbits, but prefer squash (summer and winter varieties) and pumpkins. Adults are a little over a ½ inch long and are dark brownish while nymphs are black, pale green or gray with black legs. These insects feed mainly on the leaves and the stems of squash plants, but can also feed on the fruits. Initially they cause a stippling on the leaves, but after heavy feeding the leaves begin to look tattered.
Squash bug adult laying eggs
Squash bugs overwinter as adults, so at the end of the season cleaning up plant debris and mulch will remove overwintering sites. Eggs are bronze colored and usually laid in clumps on the underside of leaves. Removing and destroying egg masses can help keep squash bug numbers down. Adults and nymphs are known to hide in mulch around the base of the plants, laying down a board or piece of cardboard will provide a hiding place for these bugs. You can then remove the shelter and destroy all the bugs underneath it. There are also some cultivars of both summer and winter squash that are resistant to squash bugs.
Of course there are lots of non-insect pests that can wreak havoc on your garden as well and whose damage can sometimes be confused with insect damage. Snails and slugs have rasping mouth parts that create holes in plant leaves much like insects that have biting/chewing mouth parts. Spider mites having piercing/sucking mouth parts that cause stippling on plant leaves like the “true bugs”.
So as you try to determine what is causing damage to your plants keep in mind that different kinds of insects cause different kinds of damage and that determining the cause is essential to developing a solution.
Note: Pesticide recommendations are not a substitute for pesticide labeling. Remember to read the label before applying any pesticide. The label is the law!
Help survey the Hudson Valley Region for potential new forest pests. Reports of invasive pests newly detected in New York are causing great concern. These include spotted lanternfly (Lycorma delicatula), Asian longhorned tick (Haemaphysalis longicornis) and jumping worms (Amynthas sp.). Reporting their presence and stopping their spread are urgent needs. You can help.
Spotted lanternfly (SLF) is an invasive planthopper that can feed on a wide variety of plants including grapevines, hops, maples and fruit trees. It is established in neighboring states and may be moving into our region.
This workshop will prepare interested individuals such as gardeners, hikers, landscapers and forest managers to scout for and identify SLF. Trainees will be asked to be “boots on the ground” to assist in the detection of the pest, to report it to NYS DEC and to help prevent its spread in our area. The biology, identification, potential damage, methods of spread, monitoring and management of SLF will be described. The Blockbuster Surveyor protocol and iMapInvasives app will be reviewed to track the current distribution and abundance (or absence) of SLF.
Identification information will also be provided for Tree of Heaven, Ailanthus altissima, the SLF’s favorite host; an emerging pest, Asian Longhorned Tick, Haemaphysalis longicornis; and Jumping Worms, Amynthas sp., which are in our region but under-reported.
CCE offices in the region will host the trainings in May. Register with the links below:
Questions can be addressed to Joyce Tomaselli, CCEDC, jdt225@cornell.edu, 845-677-8223 ext. 134
This program is part of the Lower Hudson Partnership for Regional Invasive Species Management’s efforts to stop the spread of invasive species in the Lower Hudson Valley. Visit www.lhprism.org for more information on how the LHPRISM strives to address invasive species issues through its partnerships. Click on “Upcoming Events” or “Get Involved” to learn more.
Mosquitoes are beneficial to plants as well. Many adult mosquitoes depend on plant nectar for their energy, and while retrieving the nectar, they also pollinate plants. And as we know that pollination is key to plant reproduction, mosquitoes play an important role in helping plants survive so they can provide food and shelter for other organisms.
By Kimberly Marshall, Washingtonville Master Gardener Volunteer
How to identify the squash vine borer and the damage that it does:
How to minimize damage if borers have found your garden anyway:
