Wondering what common bugs are in your garden? Since not all insects are bad, browse the bug chart below to find out if the critters on your plants are beneficial or harmful.
Aphids - Harmful
- Found: Aphids are found on many plants including fruits, vegetables, trees and shrubs. They feed on juices from the plant's stems and leaves.
- Effects on crops: Large numbers of aphids can cause leaves to curl and plant growth to become stunted. Aphids secrete honeydew as they feed, which attracts ants and causes a black sooty mold to grow on the leaves.
- How to treat: Natural predators include lady beetles, parasitic wasps, crab spiders, and lacewings. Organic gardening insecticides like insecticidal soap and neem oil will kill aphids.
- General info: There are over 4,000 aphid species found throughout the world. Aphids are small, pear-shaped, wingless insects that feed in colonies on the new growth of virtually any plant they come across. They can be green, red, black, brown or yellow in color. If populations are high, some can grow wings in order to move to other plants. As they feed, aphids secrete a sticky substance called honeydew that will attract ants and promote the growth of a black sooty mold on the plant.
Armyworms - Harmful
- Found: Armyworms feed of the foliage and fruit of many plants and grasses including corn, tomatoes, cabbage, lettuce, barley, peppers and beans.
- Effects on crops: Armyworms eat through the leaves of many plants causing them to look skeletonized. They can also eat through corn kernels, and damage grass in lawns.
- How to treat: Natural predators include birds, lady beetles, parasitic wasps, minute pirate bugs, lacewings and beneficial nematodes. Organic gardening insecticides like insecticidal soap and neem oil will kill armyworms. Biological insecticides approved for organic gardening like bacillus thuringiensis var kurstaki (Bt-k) and spinosad also work well to eliminate these insects.
- General info: Armyworms are the destructive larvae of gray moths. They will feed on a variety of grasses and vegetable crops, damaging both the fruits and the leaves of the plant. Adult moths will migrate to warm climates in the winter and return to Northern areas in the spring to lay their eggs once again. Many bird species will eat the moths and larvae, helping to control the infestations. However, if infestations are high, chemical controls may be necessary to completely eliminate these insects.
Bagworms - Harmful
- Found: Bagworms feed on the needles and leaves of trees in the evergreen species. They also are found feeding on certain deciduous trees like black locust, honeylocust and sycamore.
- Effects on crops: Bagworms injure trees by leaving holes in the foliage that could lead to defoliation of the tree.
- How to treat: Natural predators include parasitic wasps, sparrows and white footed mice. Biological insecticides approved for organic gardening like bacillus thuringiensis var kurstaki (Bt-k) and spinosad will eliminate these insects.
- General info: Bagworms are easily recognized by the bag they attach to the plants they feed on. The bags are made of silk and plant foliage, and each one holds an individual bagworm larvae as they feed and mature. Tree needles and leaves will be eaten by these insect pests, and heavy infestations could lead to defoliation of the tree. The good news is, trees typically refoliate the next season if the bagworm population is controlled. If infestations are small, handpicking and disposing of bagworms is effective. For large infestations, chemical controls may be needed.
Black Swallowtail Butterfly - Neutral
- Found: Black swallowtail butterflies eat mostly nectar from flowers. However, their larvae feed on carrots, celery, parsley and dill.
- Effects on crops: Adult butterflies are not generally considered pests as they help pollinate plants. Their larvae however, can be a nuisance to gardeners since they consume the leaves of plants in the parsley family.
- How to treat: There are not usually large numbers of larvae in one location to overtake and destroy plants. However, if they become a problem for your vegetables, hand picking and disposing of the caterpillars will usually eliminate the problem.
- How to attract: Adults are attracted to flowers such as red clover, thistle and milkweed.
- General info: Black swallowtail butterflies are easily identified by their black wings with yellow and sometime pale blue spots. Adults are generally considered to be beneficial insects because they are natural pollinators of flowers and plants. However, if you're trying to grow carrots or parsley, their larvae may become a nuisance since they feed almost entirely on these plants. If your plants are being eaten by unwanted larvae, they can easily be controlled by simply picking them off and disposing of them.
Boxelder Bug - Harmful
- Found: Boxelder bugs feed almost exclusively on maple trees, but they occasionally will damage apples, peaches, grapes, strawberries and plums.
- Effects on crops: Damage is typically minor, but boxelder bugs can sometimes cause the leaves of maple trees to brown and discolor. If they do feed on fruit, it will usually cause only slight cosmetic damage in the form of bruises.
- How to treat: Organic gardening insecticides like insecticidal soap or pyrethrin sprays will kill boxelder bugs. Powders like borax and diatomaceous earth will also kill boxelder bugs by damaging their outer shell as they contact the powder.
- General info: Boxelder bugs are sap-sucking insects who feed almost exclusively on the seedpods of maple trees. Though boxelder bugs don't generally cause significant damage to plants, they can still be a nuisance in many homes and gardens. In summer, they typically congregate in large numbers on trees and the outside of homes. They often make their way indoors as the weather turns cooler, looking for a place to overwinter. Avoid the urge to squash them as they can emit a foul odor and leave a stain. Instead, opt to vacuum them up for removal.
Braconid Wasp - Good
- Found: Braconidae are found on nectar producing plants like yarrow and small-flowered daisies.
- Effects on crops: These beneficial parasitic wasps feed on a wide range of garden insect pests such as aphids, hornworms, sawflies, and beetle larvae.
- How to attract: To attract adult parasitic wasps, plant nectar producing flowers.
- General info: Braconidae are parasitic wasps that help eliminate damaging insect pests from gardens. There are over 100,000 different species of braconidae found throughout the world. Adult wasps lay their eggs inside a host insect. When the eggs hatch, the larvae feed on the insides of their host, effectively killing it. Braconidae are particularly fond of feeding on tomato and tobacco hornworms. Nectar and pollen producing flowers can be planted near plants that are infested with nuisance insects to attract adult parasitic wasps.
Bumblebee - Good
- Found: Bumblebees are found on garden flowers and the flowers of vegetables and fruits.
- Effects on crops: Bumblebees are one of the best natural pollinators in the world. They carry the pollen of flowering plants to other nearby plants, effectively increasing the size and amount of fruit produced.
- How to attract: Plant flowers along with your fruits and vegetables to attract bumblebees. You can also plant trees, shrubs and native flowers in your landscape that bloom at different times throughout the year to provide a continuous source of blooms for the bees.
- General info: Bumblebees are the worker bees of the insect world. They have an interdependent relationship with the flowers they help pollinate. Bumblebees look to pollen producing plants as a source of food, and pollen producing plants look to bumblebees for the natural pollination they provide to grow larger and more productive fruit and blooms. If you're looking to attract bumblebees, it's best to start by planting flower species that are native to your region as local bumblebees will already be familiar with these species.
Cabbage Worm - Harmful
- Found: Cabbage worms are found on the leaves of cabbage, cauliflower, broccoli, kale, and brussels sprouts.
- Effects on crops: Larvae will feed on the leaves of plants, leaving behind irregular holes. As they grow, they can bore into the center of the plant, contaminating them with fecal pellets.
- How to treat: Natural predators include parasitic wasps, spiders, green lacewing, and insect-eating birds. Biological insecticides for organic gardening like bacillus thuringiensis var kurstaki (Bt-k) and spinosad will eliminate these insects.
- General info: Telltale signs of a cabbage worm infestation are the tiny holes found all over the leaves of cabbage and other brassica plants. These holes start small, but grow in size as the worm grows, causing significant damage. Cabbage worms are typically green in color, blending in with the host plant and making them difficult to spot without signs of damage. If left untreated, these worms will eat their way into the heart of the plant, leaving behind traces of fecal matter. Unfortunately, once a plant is contaminated with fecal matter, it's unfit for consumption and will need to be destroyed.
Cucumber Beetle - Harmful
- Found: Cucumber beetles feed on the leaves and fruit of cucumbers, beans, squash, melons, corn, peas, potatoes, tomatoes, and various other fruits and vegetables.
- Effects on crops: Cucumber beetles will eat tiny holes in the plant's leaves and fruit. Overall, the plant may become stunted and lose vigor. Plants may even become susceptible to certain diseases that are spread by contact with cucumber beetles.
- How to treat: Natural predators like lady beetles, green lacewing and spined soldier bug will eat the pest eggs. Organic gardening insecticides like pyrethrin spray and neem oil will eliminate the adults. Non-organic insecticides that kill cucumber beetles include permethrin, bifenthrin, lambda-cyhalothrin, and carbaryl.
- General info: There are two types of cucumber beetles present today - the striped cucumber beetle and the spotted cucumber beetle. Both behave similarly and cause identical damage to plants and crops. Don't let the name fool you, cucumber beetles will feed on just about any garden vegetable or fruit imaginable. If infestations are not controlled quickly, damage to plant can be overwhelming, causing them to become weak and have stunted growth. Cucumber beetles are also carriers of bacterial wilt, a disease that can further devastate infected plants.
Eastern Yellowjacket - Good
- Found: Eastern yellowjackets visit fruits and flowers looking for insects to consume, but often end up feeding on the nectar and pollen instead.
- Effects on crops: Eastern yellowjackets are natural predators of many unwanted garden insects like destructive caterpillars and worms, making them beneficial to plants.
- How to attract: Plant a variety of flowers and fruits to attract eastern yellowjackets. If you have garden insect pests, eastern yellowjackets will often come in search of a meal.
- General info: Eastern yellowjackets can be a nuisance to humans, especially those who are allergic, because they will sting if they feel threatened. However, they’re actually considered to be beneficial insects because they are natural predators of garden insect pests like caterpillars and earwigs. Eastern yellowjackets will visit many home gardens in search of insects, but if they don't find insects to consume, they will often feed on the nectar and pollen of fruits and flowers.
Flea Beetle - Harmful
- Found: Flea beetles consume the leaves of a large variety of plants including tomatoes, potatoes, peppers, lettuce and corn.
- Effects on crops: Flea beetles chew tiny holes in plant leaves. If infestations are high, they can quickly defoliate entire plants causing them to die.
- How to treat: Sticky traps placed near plants will help control flea beetle populations, catching them as they jump around. Organic gardening insecticides like neem oil, pyrethrin and insecticidal soap will kill flea beetles. Non-organic insecticides like carbaryl and permethrin will work as well.
- General info: Flea beetles are small jumping insects that are found feeding on many home gardens early in the growing season. They are particularly fond of hot, dry weather, and will usually launch their most severe attacks on hot, sunny days. Once flea beetles start eating the leaves of a plant, you'll notice what looks like tiny pin pricks covering the leaves. Sometimes infestation can be so severe that entire plants will die from defoliation. Flea beetles often transmit diseases when feeding, causing further damage to an already weakened plant.
Fungus Gnat - Harmful
- Found: Fungus gnat larvae are particularly fond of container plants, grown both indoors and out, feeding on their roots within the soil. Poinsettias, carnations, African violets and geraniums are most at risk.
- Effects on crops: Fungal gnats can cause plants to wilt, yellow and have stunted growth. They also can carry fungal diseases from one plant to another.
- How to treat: Beneficial nematodes can be added to the soil to control larvae. Yellow sticky traps will attract the flying adults, trapping them before they can lay more eggs. Organic gardening insecticides like pyrethrin and insecticidal soap will kill the adults as well.
- General info: Fungus gnats are attracted to places where humidity and moisture are high, making them fond of container plants grown indoors. Even though they're small in size, adults are usually noticed flying around plants or gathering at windows. While the adults can be bothersome, the larvae are the ones who cause the most damage to plants. Fungus gnat larvae live below the soil and feed on plant roots, causing plants to become weak and wilted. Yellow sticky traps and insecticide sprays will capture and kill the adults, effectively breaking the breeding cycle.
Grasshopper - Harmful
- Found: Grasshoppers feed on the leaves and stems of a variety of plants including beans, corn, carrots and lettuce.
- Effects on crops: Grasshoppers eat holes in the leaves and plant tissue. If infestations are large, grasshoppers will eat almost everything on a plant that is edible.
- How to treat: Organic gardening insecticides like neem oil, insecticidal soap or pyrethrin sprays will kill grasshoppers. Powders like diatomaceous earth will also kill grasshoppers by damaging their outer shell as they contact the powder.
- General info: Grasshoppers live and travel almost anywhere in search of food. They consume about half of their body weight each day by eating the leaves and stems of a variety of plants. In smaller container gardens, grasshopper damage is easier to limit as there are likely only a few grasshoppers present. If caught early, most plants will survive the damage and grow as normal. However, if infestations are large, grasshoppers will decimate plants, consuming almost anything on the plant that is edible.
Green Lacewing - Good
- Found: Green lacewing are found on nectar and pollen from flowers and plants.
- Effects on crops: Adult lacewing larvae are natural predators of common garden insect pests like aphids, whiteflies and caterpillars, making them beneficial to any garden.
- How to attract: Attract green lacewing by planting flowering plants like sunflowers, dill, queen anne's lace, fennel and coriander.
- General info: Green lacewing larvae are beloved by many gardeners because of their appetite for a large variety of insect pests. Even though they're only in their larval stage for two or three weeks, lacewing larvae can consume up to 600 garden pests in that timeframe. Adult lacewings feed on nectar and pollen, so they’re typically found in many flower and vegetable gardens. Lacewings are also available for purchase at many nurseries or online retailers if you’re struggling to attract them naturally.
Japanese Beetle - Harmful
- Found: Japanese beetles feed on the leaves, buds and flowers of a variety of plants including peppers, tomatoes, berries, roses and beans.
- Effects on crops: Leaves will look skeletonized as Japanese beetles feed on the plant tissue and leave the veins intact. Blossoms will look stunted or jagged when eaten by Japanese beetles.
- How to treat: Bag traps attract and trap Japanese beetles by using a powerful bait to lure them in. Organic gardening insecticides like neem oil, insecticidal soap and pyrethrin will kill Japanese beetles on contact. Parasitic wasps are natural predators of Japanese beetles.
- General info: Japanese beetles are voracious leaf-feeders who consume a wide variety of plants. Though their feeding season is short, only a few weeks in the middle of summer, the damage to plants can be severe. Bag traps are the most common methods for eliminating Japanese beetles. These traps use a strong bait to lure the beetles into the trap, effectively breaking the feeding and breading cycle. Be sure to hang traps away from plants and houses as they may attract lots of Japanese beetles to areas nearby in the process.
Lady Beetle - Good
- Found: Lady beetles are attracted to the pollen of plants such as dill, fennel, cilantro and tansy.
- Effects on crops: Lady beetle adults and larvae consume garden insect pests like aphids, spider mites and mealybugs, making them beneficial to any garden.
- How to attract: Plant pollen producing plants like geraniums, caraway, angelica and yarrow.
- General info: Lady beetles are valuable natural predators of nuisance garden insects. They're particularly fond of aphids, but will also eat mites, thrips and other crop-damaging insects. There are quite a few species of lady beetles, but the most commonly known species is the Asian lady beetle, as it's a favorite in children's nursery rhymes and picture books. Lady beetles can sometimes be bothersome to homeowners as they often come inside looking for warmth during the fall. Since these insects are so beneficial, it's best not squash them, and instead opt to simply bring them back outside where they can help protect gardens.
Leafhopper - Harmful
- Found: Leafhoppers feed on the leaves of many common fruits, vegetable and flowers including grapes, roses, lettuce, tomatoes and beans.
- Effects on crops: The saliva of leafhoppers is toxic to plants and can cause leaf spotting, yellow and curling. The overall plant can become stunted and distorted.
- How to treat: Natural predators like lady beetles, green lacewing and parasitic wasps eat leafhoppers. Organic gardening insecticides like insecticidal soap and pyrethrins will kill leafhoppers. Sticky traps will also help control leafhoppers, trapping them as they jump around.
- General info: Leafhoppers are small pests of many garden plants. They feed on the foliage by piercing the leaves and sucking out the juices. They can even promote the spread of various plant attacking viruses and bacteria, further injuring already stressed plants. They’re excellent short distance jumpers and will simply jump to nearby plants if disturbed. A simple way to monitor for a leafhopper infestation is to place yellow sticky traps near plants. Leafhoppers will get stuck on the traps as they jump from plant to plant, alerting you to a leafhopper problem.
Leafminer - Harmful
- Found: Leafminers are found on the leaves of plants like peppers, tomatoes, pumpkins, blackberries, spinach, trees and shrubs.
- Effects on crops: Leaves will appear blotchy, mottled or have zig-zag lines throughout the leaf surface.
- How to treat: Parasitic wasps are natural predators of leafminers. An organic gardening insecticide like neem oil will eliminate leafminer populations. Non-organic insecticides like permethrin, bifenthrin and carbaryl will work as well.
- General info: Leafminers, the larval stage of an insect family, dine on the leaves of fruits, vegetables, trees and shrubs. Controlling leafminers can be difficult as they often bury themselves inside the plant leaves while they feed on the plant tissue. Leafminer damage typically has little impact on plant growth, but they can be destructive to fruits and vegetables grown for consumption as they leave unsightly spots and tunnels in leaves.
Mason Bee - Good
- Found: Mason bees prefer the pollen of early flowering plants like forsythia, pieris and fruit trees.
- Effects on crops: Mason bees are effective pollinators of many flowering plant species, making them beneficial to home gardeners and farmers alike.
- How to attract: Keep mason bee nesting boxes near gardens so they can have a place to lay their eggs. Plant a variety of early flowering fruits, vegetables and flowers. If you have ample lawn space, fruit trees are a favorite amongst this beneficial species.
- General info: Mason bees are a hardworking, solitary, native bee species who play an important role in the natural pollination of fruits, vegetables and flowers. Mason bees get an early start to pollinating, as they are seen early in the growing season when many other bee species are still dormant. Mason bees are typically unaggressive, (males don't have stingers and females only sting if they are being squeezed) making them a favorite of many home gardeners. They're smaller than honeybees and have a blueish black hue, sometimes making it easy to mistake them for flies.
Mealybug - Harmful
- Found: Mealybugs are found on the leaves, stems and fruits of a large variety of vegetables, fruits, flowers and houseplants.
- Effects on crops: Mealybugs suck the sap out of plant tissue causing the leaves to yellow and curl, and the overall plant to lose vigor. Mealybugs secrete honeydew as they feed, which attracts ants and causes a black sooty mold to grow on the leaves.
- How to treat: Natural predators include lady beetles, lacewings, parasitic wasps and the mealybug destroyer. Organic gardening insecticides like insecticidal soap, pyrethrin spray and neem oil will kill mealybugs.
- General info: Mealybugs are small, wingless insects that are covered with a white, waxy substance. When a large number of them are present, it will appear like a white, cottony mass is growing on the plant. Mealybugs suck out the plant sap while feeding, and then secrete a sticky substance known as honeydew back onto the plant. Honeydew can be damaging as it attracts ants and promotes mold growth, which can further stress an already weakened plant. Mealybugs are attracted to plants with high nitrogen levels, so keep water reservoirs at consistent levels and avoid using excess fertilizer.
Monarch Butterfly - Good
- Found: Adult monarch butterflies feed on the nectar of many plants including lilacs, red clover, asters and wild carrots. Larvae feed on exclusively milkweed.
- Effects on crops: Monarch butterflies are found on nectar producing plants and flowers, effectively pollinating many plant species as they travel from flower to flower.
- How to attract: Plant nectar producing flowers, especially milkweed, in and around gardens. Monarchs also get minerals and moisture from damp soil and wet gravel, so consistent watering is a must.
- General info: Monarch butterflies are an iconic pollinator butterfly species with their white-spotted bodies and distinct gold and black wings. They make an annual migration across North America, moving from Canada and the northern United States to the southernmost U.S. and Mexico in the fall, and back again in the spring. There is increasing concern over the decline of the monarch butterfly species due to herbicide use, migration loss and natural predators. Efforts are being made to preserve their natural habitats and increase awareness about responsible herbicide practices to limit the effects on these natural pollinators.
Orb Weaver Spider - Good
- Found: Orb weave spiders make their webs anywhere with structural support like outdoor lights, trees, bushes and tall grasses.
- Effects on crops: These beneficial spiders eat insects, thus reducing the populations of many garden insect pests.
- How to attract: Provide structural support for webs near gardens like poles and tall grasses.
- General info: Orb weave spiders are generally non-aggressive spiders that prey on insects caught in their web. They may look a bit frightening with their large abdomens and colorful long legs, but they are actually quite docile and will flee at the first sign of a threat. It's very uncommon for a person or animal to be bitten by an orb weaver, and it usually only happens in extreme cases where someone is trying to pick them up. Their bites, however, are not harmful. They're most active during the night, eating insects trapped in their webs in the dark.
Potato Beetle - Harmful
- Found: Potato beetles feed on the leaves of common garden plants like potatoes, tomatoes, peppers and eggplants.
- Effects on crops: Potato beetles will eat away entire leaves from plants causing plants to have reduced yields. Extreme cases may even lead to plant death.
- How to treat: Organic gardening insecticides like insecticidal soap, neem oil and pyrethrin sprays will kill adult beetles. Beneficial insects like lady beetles and green lacewing will feed on the eggs and larvae.
- General info: Colorado potato beetles are common pests for home gardeners. They're easily recognizable by their round bodies with yellow and black striped wing covers. As their name suggests, they love to feed on potato plants, but they also prefer other vegetables like tomatoes and peppers. If you notice only a few potato beetles on the leaves of your growing veggies, you may be able to get rid of them by simply picking them off and placing them in a bucket of soapy water. However, keep an eye out for any egg clusters hiding on the undersides of plant leaves, and take steps to remove those too before they hatch.
Praying Mantis - Good
- Found: Praying mantis can be found on almost any garden plant, using the plant foliage for camouflage as they stalk their prey.
- Effects on crops: Praying mantis eat many garden insects including destructive aphids, leafhoppers and grasshoppers.
- How to attract: Attract praying mantis to your garden by offering hiding places like tall grasses and shrubbery.
- How to attract: Adults are attracted to flowers such as red clover, thistle and milkweed.
- General info: Praying mantis are carnivorous insects that provide a major natural service to your garden by dining on just about any insect that they come in contact with. They use their spiked front legs and fast reflexes to catch insects as they crawl or fly by. Be careful though, as they will often eat other beneficial insects too. Female mantis lay their eggs on twigs, branches and other hard surfaces. Eggs are surrounded by a hard egg case that's about the size of cigarette filter. The following spring, they will hatch and be ready to eat insect pests almost immediately.
Slugs - Harmful
- Found: Slugs feed on the foliage and fruit of garden plants. They are particularly fond of low-growing leafy greens and ripe fruit.
- Effects on crops: Slugs chew holes in plant foliage and fruit, sometimes causing extensive damage.
- How to treat: Iron phosphate baits will work as a poison to slugs and are approved for organic gardening. Non-organic gardening metaldehyde baits will also kill slugs. Homemade beer-baited traps buried at ground level may also attract and catch slugs.
- General info: You’ll know you have a slug problem in your garden by the telltale slime trails leading to slug hiding places. When not chewing holes in plant foliage, slugs will usually be found hiding in damp, shady spots under rocks and along house foundations. Home gardeners generally wake up to see the damage left by slugs, but not the actual slugs themselves, as they're most active during the night. Even though they feed on plants just like many insects do, slugs are actually considered part of the mollusk family and are not true insects.
Snails - Harmful
- Found: Snails feed on the foliage, flowers and fruit of a large variety of garden plants including lettuce, strawberries and tomatoes.
- Effects on crops: Snails chew holes in plant foliage and fruit, sometimes causing extensive damage.
- How to treat: Iron phosphate baits will work as a poison to snails and are approved for organic gardening. Non-organic gardening metaldehyde baits will also kill snails. Homemade beer-baited traps buried at ground level may also attract and catch snails.
- General info: Snails are closely related to their equally destructive counterparts, slugs. Both snails and slugs are part of the mollusk family and the only major difference is that snails have an external spiral-shaped shell that they can completely retract into. Snails are most active at night or on cloudy days. You will know you have a snail problem in your garden by the chewed fruit and foliage and the slime trails that lead to the snail’s daytime hiding spots under rocks and along home foundations.
Spider Mite - Harmful
- Found: Spider mites are found on the underside of plant leaves. They will feed on a large variety of plants including fruits, vegetables, flowers, houseplants and trees.
- Effects on crops: Plants affected by spider mites will have leaf spotting and curling, and they may even lose leaves entirely.
- How to treat: Natural predators include lady beetles and green lacewing. Insecticidal soap, neem oil and pyrethrin sprays are approved for organic gardening will kill spider mites.
- General info: Spider mites are a type of tiny arachnid, and are not actually considered insects. They are so small that an individual spider mite cannot usually be seen by the naked eye. You will likely only know you have a spider mite problem when your plants begin to show signs of stress and you notice a fine webbing underneath plant leaves where many spider mites gather. Stressed plants are more susceptible to mite infestations, so keep water reservoirs full to encourage healthy, strong plant growth.
Squash Bug - Harmful
- Found: Squash bugs feed on the leaves, vines and fruits of vegetables in the cucurbit family like melons, pumpkins, cucumbers and squash.
- Effects on crops: Squash bugs simultaneously suck sap from plants while injecting a toxic substance back into the plant causing it to wilt. Leaves may become discolored and dry out, and in severe cases entire plants may die.
- How to treat: Insecticidal soap, neem oil and pyrethrin sprays will kill squash bugs and they are approved for use in organic gardening. Parasitic flies lay eggs directly on squash bugs, eventually hatching and killing the host insect.
- General info: Squash bugs live up to their names as they love to feed on squash and other members of the cucurbit family. They can sometimes be mistaken for stink bugs since they also give off a foul odor when squashed, but squash bugs have longer, thinner bodies. Squash bugs inject a toxic substance into plants while feeding and sucking out plant juices. This substance causes the plant leaves to look wilted and die, mimicking a bacterial wilt infection.
Stink Bug - Harmful
- Found: Stink bugs prefer the fleshy part of fruits, but they will also feed on other areas of plants if the fruits are not available. They will eat just about any fruit, vegetable, and leafy green they come across.
- Effects on crops: Fruits where stink bugs have fed will show browning and bruising. Stink bugs inject a digestive enzyme back into the plant while feeding, causing discoloration and sometimes early decay of the plant.
- How to treat: Natural predators of stink bugs include lady beetles, green lacewing and minute pirate bugs. Insecticidal soap and neem oil will kill stink bugs and are approved for organic gardening. Stink bug traps will attract and trap stink bugs using a special bait that lures stink bugs in.
- General info: There are many species of stink bugs in North America, but it's the brown marmorated stink bug that was recently introduced to the U.S. in 1998 that gets most of the recognition. Stink bugs get their name by releasing a foul odor as a defensive mechanism when threatened. With voracious appetites, these pests prefer to feed on the fleshy part of ripened fruits, but they will go after virtually any part of a plant if the fruit is not present. Stink bugs are also a nuisance inside the home, as they often make their way inside looking for a warm place to overwinter.
Tent Caterpillar - Harmful
- Found: Tent caterpillars feed on the foliage of various tree species like oaks, cherry, plum and basswoods.
- Effects on crops: Tent caterpillars spin large, silk-like webs onto tree branches where they consume foliage. Trees usually end up partially or completely defoliated when tent caterpillars invade.
- How to treat: Biological insecticides like bacillus thuringiensis var kurstaki (Bt-k) and spinosad will eliminate tent caterpillars and are approved for organic gardening. Some bird species like orioles, jays and nuthatches will eat tent caterpillars, and can help reduce the population.
- General info: You'll know you have a tent caterpillar problem on your trees by the large, silken webs formed on the branches. These webs are used to protect the caterpillars from predators and the elements while they munch away at the foliage underneath. The good news is, if your trees are healthy, they will usually refoliate once the tent caterpillar infestation is eliminated. Tent caterpillars can also be a nuisance in lawns, driveways and walkways as they migrate to other nearby trees. They can be spotted traveling on these surfaces sometimes by the thousands.
Thrips - Harmful
- Found: Thrips feed on a large variety of fruits, vegetables and flowers. They can be found feeding on plant leaves, flowers and fruit.
- Effects on crops: Thrips suck out the juices of plants through the fruits, flowers and leaves. Plant leaves end up splotchy with a silvery appearance, and the overall plant can look twisted and discolored.
- How to treat: Natural predators include lady beetles and lacewings. Insecticides like insecticidal soap, pyrethrin spray, neem oil and spinosad eliminate thrips and they're approved for use in organic gardening. Sticky traps can be hung near plants to trap thrips as they fly away.
- General info: The tiny insects known as thrips are virtually impossible to spot with the naked eye, as they're only about 1/25 of an inch in length. They feed in large groups, multiplying the damage they cause to plants. With two pairs of feathery wings, they will fly away when the plant they’re feeding on is disturbed. Thrips do overwinter on plant debris, so it's important to thoroughly dispose of any leftover plant material after harvest.
Tomato Hornworm - Harmful
- Found: Tomato hornworms can be found on tomatoes, eggplants, peppers and other nightshade vegetables. They will feed on the leaves, stems and fruit of the plant.
- Effects on crops: Hornworms damage vegetables by chewing holes in the fruit and leaves. If left untreated, they can defoliate your plant in just a few days.
- How to treat: Natural predators include parasitic wasps, lady beetles and lacewings. Biological insecticides like bacillus thuringiensis var kurstaki (Bt-k) and spinosad will eliminate hornworms and are approved for organic gardening. Organic gardening insecticides like insecticidal soap will kill hornworms as well.
- General info: Tomato plants and other nightshade vegetables are excellent at attracting the unwanted tomato hornworm. These large caterpillars eat holes in the fruit and leaves of plants, causing extensive damage in a short amount of time. You can easily recognize these bright green caterpillars by the large horn or spike on its tail end. Eventually these caterpillars become moths, but their destructive larval stage is what gives gardeners the most trouble.
Webworm - Harmful
- Found: Webworms are found on the leaves of shade trees and shrubs. Some of their favorite tree species include hickory, cherry, walnut and birch.
- Effects on crops: Webworms will feed on and skeletonize leaves under the protection of a web-like tent that they attach to the branches of a tree.
- How to treat: Natural predators of webworms include birds, parasitic wasps and flies. Biological insecticides like bacillus thuringiensis var kurstaki (Bt-k) and spinosad will eliminate webworms and are approved for organic gardening. Other insecticides approved for organic gardening are insecticidal soap and pyrethrin sprays. Non-organic insecticides include carbaryl and acephate.
- General info: Fall webworms, or simply webworms for short, feed on almost all trees except evergreens. They protect themselves in tent-like webs attached to tree branches and consume the leaves underneath. When webworms are done feeding, leaves will look skeletonized and bare. Though this is certainly unsightly, trees are rarely killed when under a webworm infestation. Typically, trees will refoliate as normal the following year after the webworm infestation is controlled. Since webworms hide in protective tents, you may need to use a high-pressured sprayer to penetrate the webs while treating with insecticides.
Western Honey Bee - Good
- Found: Western honey bees are found on the flowers of pollen and nectar producing plants.
- Effects on crops: Western honey bees are natural pollinators of a variety of flowers, fruits and vegetables, making them an essential part of gardening.
- How to attract: Plant a variety of pollen and nectar producing vegetation near gardens to attract western honey bees.
- General info: Western honey bees are extremely important to the natural pollination process that flowers, fruits, vegetables and trees need to grow and thrive. The worker bees have special pollen baskets on their hind legs that carry pollen back to the hive. Pollination occurs when small pollen fragments drop from the pollen baskets onto other flowers as the bees are flying. Bees are responsible for pollinating more than 30% of the food we eat each year. Many people choose to raise honey bees not only for their pollination purposes, but also for the abundance of raw honey produced from their hives.
Whitefly - Harmful
- Found: Whiteflies are found on the undersides of leaves, typically attacking the new growth of a plant. They feed on more than 250 plants including tomatoes, grapes, cucumbers and poinsettias.
- Effects on crops: Whiteflies suck the sap out of the leaves, causing them to yellow and the overall plant to have stunted growth and reduced yields. They also secrete honeydew as they feed, attracting ants and promoting the growth of a black sooty mold.
- How to treat: Natural predators include lady beetles and lacewings. Insecticides like insecticidal soap, pyrethrin spray, and neem oil eliminate whiteflies and they're approved for use in organic gardening. Sticky traps can be hung near plants to trap whiteflies as they fly away.
- General info: Whiteflies are common sap-sucking insects found on the underside of plant leaves. They typically congregate in large numbers and will fly into the air when disturbed. You're likely to find whiteflies in warmer regions and they will feed on just about any plant they can find. It's easy to miss early signs of whiteflies on plants as they are only about 1/16 of an inch long. Inspect plants at least once a week to look for signs of whiteflies, including inspecting both sides of plant leaves.