Correctly identifying the insects and other pests that attack vegetables is the first step toward controlling these pests effectively. The pest descriptions in this booklet are designed to help the commercial vegetable grower and home gardener recognize the insects found on vegetables. Information on insect life cycles and habits is included to make pest control recommendations more understandable and usable. Most of the insects considered common vegetable pests undergo a developmental process known as metamorphosis, which simply means that the insect changes form during its life. Metamorphosis may be complete or incomplete. Complete metamorphosis consists of four stages -- egg, larva, pupa, and adult.
All insect life cycles include an egg stage. The insect is immobile during this stage. A larva hatches from the egg. The larval stage is the growth stage and frequently the pest stage of insect life. This is especially true of moths, butterflies, and true flies. Larvae of moths and butterflies are commonly known as caterpillars. Maggots are the larvae of true flies. Many beetles exist as grubs during the larval stage. Larvae vary in size from as short as 1/8 inch to as long as 4 inches. The larva molts, or changes and enters the pupae stage. During the egg stage, the insect is immobile during this pupae period. It is during this stage that the insect develops into an adult. Adults may or may not feed in the same way and on the same plants as larvae. Beetles, for example, have chewing mouth parts and, like many grubs (beetle larvae), are capable of causing great damage to vegetables. Moths and butterflies, on the other hand, have mouth parts designed for siphoning and are unable to damage plants.
Incomplete metamorphosis consists of three developmental stages -- egg, nymph, and adult. The egg stage is similar whether an insect undergoes complete or incomplete metamorphosis. Immature insects called nymphs hatch from eggs. Nymphs damage plants and reduce vegetable quality by sucking plant juices. Some insects damage plants not only by extracting juice but also by injecting saliva into the plant. The best known example of this is the injury called hopper-burn caused by the potato leafhopper on Irish potatoes.
The pests discussed in this Article are divided into the following groups: Moths, Butterflies, and Their Young (Caterpillars); Beetles; Sap-Feeding Insects (True Bugs, Aphids, Leafhoppers, and Whiteflies); Flies; Other Insects; and Non-Insect Pests.
Moths, Butterflies, and Their Young
Caterpillars, the larval stage of moths and butterflies, damage both the foliage and fruit of a number of vegetables. These insects chew holes in foliage and fruit and leave degrading excrement and silk on plants.
Cabbage Looper
This caterpillar feeds on the underside of leaves of cabbage and related crops and on lettuce, spinach, beets, peas, and tomatoes. It chews irregular holes through leaves. Moths lay greenish-white eggs on the upper surface of leaves. Larvae, or worms, are 1-1/2 inches long when full grown. Larvae are pale green with four thin, white lines along the back and a wide, pale line on each side of the body. These lines can be seen easily, even on small larvae. The head is narrower than the thorax (body section behind the head). The larvae move in a measuring or looping motion, thus the insect's name. When disturbed, loopers rear upwards. Larvae go into a resting or pulpal stage in a flimsy, lace-like cocoon on the plant. The adult is a brown moth with silver markings on the wings. It has a wing spread of about 1-1/2 inches. There may be three or more generations per year, the number of worms increasing greatly with each generation. Cabbage loopers do not overwinter in The US. Moths from Georgia and Florida move into the state each year near the middle of May.
Beet Armyworm
Similar to the true armyworm, this insect is a general feeder and attacks foliage, stems, and sometimes roots of a wide variety of vegetables. Among plants attacked by this pest are beets, asparagus, corn, lettuce, cabbage, tomatoes, peppers, potatoes, onions, and peas. This pest is capable of destroying young plants. The beet armyworm overwinters as a pupa, emerging as an adult in the spring. The adult is a moth with a 1-1/4 inch wingspread. The moth's grayish brown front wings are marked with lighter lines and a spot near the center of the wing. Hind wings are white with brown edges and veins. Females lay between 500 and 600 eggs over a 4- to 10-day period. Irregular egg masses are covered with scales from the moth. Mature larvae are green with a prominent dark stripe along each side. Larvae have a dark spot on each side of the thorax, are 1-1/4 inches long, and pupate in the soil There are several generations a year.
Corn Earworm
(Also called Tomato Fruit worm and Bollworm)
This caterpillar feeds on a wide range of vegetables and, as a result, is known by several names. It may attack almost any vegetable but does the most serious damage to corn and tomatoes. Other vegetables attacked include peppers, eggplant, beans, okra, sweet potatoes, lettuce, and cabbage. Fresh corn silk is preferred by this pest as a location to deposit eggs. Eggs may hatch as soon as two or three days from the time they were deposited. Newly hatched larvae feed on buds and leaves or on corn silks. When they are four or five days old, larvae travel down the silks and feed on kernels at the end of the corn ear. If fresh corn silk is unavailable, moths prefer laying their eggs on tomato foliage, especially when plants are flowering. Larvae attack tomatoes from the time the fruit forms until it ripens, boring into the sides of the fruit and near the stem. Sometimes a small, black entrance hole is the only visible sign that a large worm is inside a tomato. Injury to tomatoes is most severe in the late summer and fall. When full-grown, larvae are about 1-1/2 inches long. They may be brown, green, or pink, with lighter colored longitudinal stripes. The head is yellow, and the underside of the body is always lighter than the back. Larvae enter the soil to pupate. Moths are cream to grayish-brown, have green eyes, and are marked with a dark spot near each wing tip. They have a wingspread of about 1-1/2 inches. Hind wings are light colored with darker areas near the edges. Moths deposit yellow eggs one at a time on plants. One female can lay as many as 3,000 eggs. There are usually three and sometimes a partial fourth generation of earworms each year.
Cutworm
Many kinds of cutworms attack vegetables. Asparagus, cabbage, squash, and tomatoes are particularly vulnerable. Most cutworms cut off stems of plants at or near the soil. Cutworms feed at night when temperatures are 65 degrees F or higher. During the day these insects hide just beneath the soil close to the site of the previous night's damage. This pest is capable of damage sufficient to necessitate the replanting of corn. Cutworms usually do not eat plants beyond cutting through them, although some species climb stalks and feed on the upper parts of plants, which causes less damage. When full grown, cutworms are 1-1/2 inches long. They curl up into a tight C shape when disturbed. Most cutworms are a dull color and have practically no hair. They pupate underground. Cutworms generally overwinter in the soil in the larval or pulpal stage. Adults are dull colored moths with wing spreads of 1 to 1-3/4 inches. Hind wings are usually light in color. Moths lay eggs on the stems of grasses and weeds or on bare ground. There may be more than one generation of some species each year.
Diamondback Moth
Larvae of this moth feed during the cool parts of the growing season on the underside of leaves of cabbage and related crops. Larvae feed for a time after hatching as leaf miners (see section on vegetable leaf miners). As larvae grow, they begin feeding on the external portion of leaves and buds. Feeding holes do not penetrate the entire leaf. Larvae are greenish-yellow with black hair and are about 1/3 inch long when full grown. They wriggle actively when disturbed and drop from the plant on silken threads. Larvae pupate inside a lacy cocoon attached to the leaf of the host plant. Moths overwinter in debris of collards, cabbage, cauliflower, and related crops. They have a wingspread of about 1/3 inch. Moths are gray to brown, marked with white. When at rest the moth has white, diamond-shaped markings along the back. The hind wings are paler and have a fringe of hair on the rear margin. Moths lay small, white eggs either singly or in groups of three or four on leaves. There may be five or six generations per year.
European corn borer
This borer attacks many species of plants, but corn, peppers, and Irish potatoes are the vegetables most severely damaged. European corn borers feed on leaves and in protected areas until about half-grown, when they bore into a plant's stem or fruit. Nearly an inch long when full grown, the caterpillar is cream colored, has a brown head, and is marked with small, round, brown spots. Caterpillars molt into pupae inside the host plant. This insect overwinters as nearly full-grown larvae in cornstalks at ground level. Adults are pale yellow moths with irregular dark bands running across the wings. The moth's wingspread is about 1 inch. Males are smaller and some-what darker than females. Eggs are laid in groups of up to 50 on the underside of leaves and overlap to resemble small fish scales. Most of the US sees at least two generations of this insect each year, while in the eastern part of the US, there are three generations most years.
Fall Armyworm
Like other armyworms, this insect may "march" from field to field. It often is called the shatter worm because of the destruction it causes to corn foliage. Larvae also damage corn ears as well as beans, potatoes, peppers, tomatoes, spinach, cabbage, and cucumbers. Swarms of moths move northward each spring from southern Florida and areas along the Gulf Coast. Females lay about 1,000 eggs each in masses of about 150. Eggs are usually laid on grass. Larvae are very small when they hatch but reach a length of 1-1/4 inches when full grown. Larvae vary in color from light tan to green or nearly black, are decorated with thin, yellow stripes, and have a prominent inverted white Y on the front of the head. Larvae go into the soil to pupate. Adult moths have dark gray front wings that are mottled with light and dark splotches. The wingspread of the adult moth is about 1-1/4 inches. Hind wings are grayish-white. Males have a white spot near each wing tip. It appears that this insect cannot overwinter in most of the US. Most years there are many generations of the pest.
Imported Cabbageworm
(Also called Cabbage Butterfly)
This caterpillar attacks cabbage, cauliflower, kale, collards, mustard, radish, and turnips. Larvae riddle outer leaves with irregularly shaped, often large holes. Caterpillars are capable of doing enough damage to severely retard plant growth. Females lay one egg per leaf on the underside of leaves. Eggs hatch into caterpillars that are 1-1/4 inches long when full grown. Caterpillars are velvety-green and are decorated with three indistinct gold stripes, one along the back and one on each side. The pulpal stage of the insect is brownish-grey and has many projections or spines. This insect is commonly found attached to a leaf during the pulpal stage. Glue at the pupa's tail and a silken loop that encircles the middle of the pupa's body hold it in place. The adult is a white butterfly with one or two black spots on each wing. This pest overwinters as a pupa either on old plant refuse or on nearby posts or buildings. There are three or four generations per year.
Pickleworm
Pickleworm larvae bore into many cucurbit fruits. Cantaloupes, cucumbers, and squash are most seriously damaged. Caterpillars feed first on foliage. As the insect grows, it begins feeding on fruit. Pickleworms do the greatest damage to growing vine tips and blossoms early in the season. Larvae are initially white with black spots and have dark heads. There is a dark indention on each side on the back of the head. Larger larvae are up to 3/4 inch long and are green. Sawdust-like excrement produced by larvae can easily be seen extruding from damaged fruit. Winter is spent in the pulpal stage in a silken cocoon on crop refuse in subtropical regions of the United States. Pickleworms usually appear in early July. The adult is a moth with a wingspread of about 1 inch. Wings appear fragile and are marked with pale yellow centers and yellowish-brown margins.
Potato Tuber worm
This caterpillar does significant damage feeding on exposed potatoes in the field, riddling them with narrow, silk-lined burrows. Adults are small, narrow-winged, grayish-brown moths with a wingspread of 1/2 inch. Moths tend to fly in late afternoon and evening. Females deposit single eggs on foliage of tomatoes, potatoes and related plants, or on exposed tubers of Irish potatoes. Eggs hatch into pinkish-white or green caterpillars with brown heads. When full grown, caterpillars are about 1/2 inch long. Larvae mature in about three weeks and pupate in gray, silken dirt-covered cocoons on the outside of the tuber. A brush of long dark scales protrudes at the end of the body. Moths deposit clusters of two to seven eggs on fruit, vines, buds, and leaves. There are at least four generations per year in The US. Cultural control is possible by planting for early maturity and destroying plants immediately after harvest, thus preventing movement of the pest to later crops. To prevent damage, potatoes should be kept covered with soil before harvest, and harvested potatoes should be stored in insect-proof areas. Also, vines should be cut, raked, and burned two or three days before harvesting. There may be several generations of this insect per year.
Squash Vine Borer
This borer can be very destructive to squash and pumpkin plants. By boring into a vine near the base, this thick, white, wrinkled brown-headed caterpillar causes entire plants to wilt. The larva overwinters 1 or 2 inches in the soil within a dark, dirt-encased cocoon and molts into a pupa in the spring. Within two or three weeks after molting, the 3/4-inch-long pupa has worked its way to the soil surface and emerged as an adult. The adult squash vine borer is a moth with a wingspread of about 1-1/2 inches. The front wings are covered with metallic, greenish black scales. Hind wings are transparent. The abdomen is ringed with red and black. Squash vine borer moths look and act like paper wasps. Females lay red eggs near the base of plant stems. Eggs produce smooth, white caterpillars that bore into the center of the vine a few days after hatching. Small piles of green excrement and wilting of whole vines are signs a plant is infested with squash vine borers. There are two generations of this pest each year. Damage is usually noticed in early June and again in early August.
Tomato Hornworm and Tobacco Hornworm
Tomato and tobacco hornworms feed on tomatoes, peppers, potatoes, and related plants. These green worms are 3 to 4 inches long and can defoliate young plants. Mature tomato hornworms can be distinguished by eight L-shaped, white markings along each side of the body and a bluish-black horn near the rear end of the insect. Tobacco hornworms are decorated with diagonal white bars and have a red horn. The white cocoons of a parasite are usually attached to the worm. Pupae of both species are mahogany brown and are found in the soil. In both species, adults are large, gray moths with mottled front wings. Hind wings are lighter. Two thin, zigzag lines run across the midsection of each hind wing of tomato hornworm moths. There is a dark area between these somewhat obscure lines on the wings of tobacco hornworm moths. On both species, five or six yellowish-orange spots can be found along each side of the body. Moths of both species have a wingspread of 4 to 5 inches and fly mainly around dusk. Females lay eggs individually on plants. Eggs are spherical and greenish-white. This insect overwinters as a pupa.
True Armyworm
This caterpillar is sometimes present in very high numbers. Armyworm epidemics can result in the destruction of large areas of vegetation. This pest attacks grasses, corn, and some legumes. Damage usually starts at the edge of a field. Larvae feed at night and may move in hordes. Armyworms are capable of consuming corn plants up to 8 inches tall. This insect stops feeding and overwinters as a partially grown larva. It resumes feeding in the spring. Armyworms are dark greenish-brown worms up to 2 inches long with white stripes down the sides and back. The insect pupates just below the surface of the soil.
Yellow striped Armyworm
This caterpillar is a daytime feeder. It is capable of doing significant damage to young tomato plantings, pepper fruit, and, occasionally in August, to sweet potatoes. Its presence is sporadic, however. Overwintering as pupae in the soil, yellow striped armyworms emerge as moths in the spring. Adults are brown, black, and white moths with a 1-1/2 inch wingspread. The moth's forewings are marked with a diagonal band that runs from the front to the rear of the wing and a smoky white stripe along the outside edge of the wing. Hind wings are white with a dark edge. Eggs, covered with scales from the female's body, are laid in clusters on foliage, trees, and buildings. Larvae are dark green with a yellowish-orange stripe along each side and black spots on their abdominal segments. There are several generations a year.
Beetles
Adult beetles are usually hard-bodied insects with thick forewings. The young are grubs, borers, or wireworms. Often adults feed on different host plants than do larvae, although both stages may be destructive to vegetables.
Asparagus Beetle
There are two beetle species that feed on asparagus -- the asparagus beetle and the spotted asparagus beetle. The spotted asparagus beetle (which is reddish-orange and black) is more destructive in asparagus production areas. Asparagus beetles are more troublesome in The US. The asparagus beetle is metallic blue with six yellow areas on the wing covers. Beetles are about 1/4 inch long and have a narrow, red head and thorax. This pest overwinters in protected areas and first appears each year in early April along the edges of fields. Adults gnaw tender asparagus buds and lay eggs on developing spears. Eggs are very dark, bullet like, and laid in rows. Processing plants sometimes reject otherwise edible spears because eggs have been laid on them. Eggs hatch within a week of the time they were laid. Sluggish, humpbacked, slate-colored larvae with black heads feed and grow on asparagus ferns for about 10 days. The pulpal stage is passed on the soil. A week or so after pupation, adults emerge and the cycle is repeated. There may be as many as five generations in a year. Asparagus is the only vegetable this insect attacks.
Bean Leaf Beetle
Adult bean leaf beetles range in color from red to yellow. The insect's markings may also vary, but bean leaf beetles generally have a dark triangular mark on the front of the wing covers, six black spots in the center of the back and a black edge around the outside of the wing covers. This insect is about 1/4 inch long and is long-lived. Adults will drop from foliage when disturbed. Bean leaf beetles feed on foliage, making round, and regular holes. This pest also attacks the stems of young plants at or slightly below ground level. Females lay eggs in the soil near the base of plants. From the eggs hatch slender, white larvae that feed on the roots of bean plants. Bean leaf beetles spend the winter as adults in trash near bean fields. There is one generation, possibly two, per year. Beans, peas, cowpeas, and soybeans are common host plants; however, this pest will also feed on corn, some clovers, and many weeds.
Blister Beetle
Several species of blister beetle feed on vegetables. The black, striped, and margined blister beetles are the most commonly seen. Blister beetles are slender, rather soft insects with a narrow thorax. The tip of the abdomen is exposed beyond the wing covers. Adults are black or gray and sometimes have narrow, yellow or gray stripes or edges on the wings. Adult beetles are ravenous feeders and are capable of destroying plants. The winter is passed as larvae in the soil. Larvae are about 1/3 inch long and yellow. Blister beetle larvae are beneficial in that they feed on grasshopper eggs. The pulpal stage also is spent in the soil. Adults emerge from the soil in midsummer and feed in groups for about five weeks. The beetle's body contains oil called cantharidin that causes blisters if the insect is crushed against tender skin. Yellow eggs are laid in holes in the soil in clusters of 100 or more. It appears there is one generation per year. Blister beetles will attack most types of vegetables but seem to prefer potatoes and tomatoes.
Colorado potato beetle
This insect is perhaps best known as the common yellow- and black-striped potato bug. This pest is, however, a beetle and not a true bug. Both adults and larvae feed on the foliage of potatoes. While potatoes are preferred, this pest also attacks tomatoes, eggplant, peppers, and horse nettle. Adults are about 3/8 inch long and 1/4 inch wide and very convex in shape. Black and yellow stripes run lengthwise along the insect's back. Females lay clusters of 20 or more yellowish-orange eggs on the underside of leaves. A single female beetle can lay over 500 eggs over the course of her four-week life. From the eggs come red, hump-backed, soft-bodied larvae decorated with two rows of black spots along each side of the body. Larvae begin chewing on leaves immediately after hatching. Larvae also feed on the fruit of tomatoes and eggplant. In two or three weeks larvae grow to a length of 1/2 inch, and then enter the soil to pupate. Seven days later adult beetles emerge from the soil, feed for a few days, mate, and lay more eggs. This insect overwinters as an adult in the soil. There are at least two generations per year.
Cowpea Curculio
This insect most commonly attacks black-eyed and Crowder peas. Adults are black, humpbacked snout beetles about 1/4 inches long. The adult female chews a hole in a pea pod and inserts an egg into the developing seed. This small puncture is difficult to see, and damage may go unnoticed until the crop is harvested. Eggs hatch into small, white, legless grubs with yellowish-brown heads. The grubs destroy the peas in a pod. There is at least one generation per year. Hot, dry weather appears to retard development of this pest. Adults overwinter in refuse around fields. Damage may be avoided by alternating from year to year the site where peas are planted.
Flea Beetle
The many different species of flea beetle attack a variety of vegetables. Species that attack potatoes, tomatoes, and eggplant are the most troublesome, but flea beetles also damage corn and sweet potatoes. Flea beetles are so named because of their enlarged hind legs and jumping ability. Adults are 1/16 to 1/18 inch long and usually black with brown legs and antennae. Eggs are laid in the soil at the base of plants. Larvae commonly feed on roots, often riddling them with tunnels or eating off rootlets. The pulpal stage is spent in the soil. These insects overwinter as adults in trash around field borders and in ditch banks. There are three or more generations per year. Round holes chewed in leaves are the most obvious damage caused by flea beetles. On small plants, this "buckshot" damage can result in plant death. On larger plants these feeding sites provide a good entrance for several blights and wilts.
Japanese beetle
These beetles are metallic green or greenish-bronze, 1/2 inch long with red wing covers, and are decorated with white spots near the tip of the abdomen. They commonly are found in June and July on fruit, deciduous trees, and vegetables. Japanese beetles also are frequent and persistent pests of sweet corn and beans. The insect spends the winter in the soil as a white grub about 3/4 inches long. Beetles emerge from the soil in midsummer and on warm, sunny days swarm to plants, where they eat the foliage, flowers, and fruit. Female beetles then return to grassy areas to lay their white, spherical eggs in the soil. Grubs feed on decaying vegetation and grass roots. Pupation occurs in the soil. There is only one generation each year.
Mexican bean beetle
The brown Mexican bean beetle is decorated with 16 black spots arranged in three rows across its back. Beetles are 1/3 inches long, convex, and resemble lady beetles. Adults overwinter on the ground among leaves and trash near fields where beans were grown. When warm weather arrives in the spring, they leave their overwintering sites and feed on beans for a week or two. Females lay lemon-colored eggs in groups of 25 or more on the underside of leaves. Eggs hatch about 10 days after being laid and yellow larvae with six rows of black-tipped, branched spines on their backs appear. Larvae, which are 1/3 inch long when full grown, feed for two to five weeks, and then enter the pulpal stage. The yellow pupa is attached to a leaf. Traces of the last larval skin can usually be found where the pupa is attached to the leaf. There are three or four generations per year. Both larvae and adults feed on leaves, usually on the underside. Damaged leaves have a skeletonized or lace-like appearance. Sometimes stems and pods are damaged. The insect attacks all kinds of garden beans, cowpeas, and soybeans.
Spotted Cucumber Beetles
(Also called the Southern Corn Rootworm)
In its adult form, this insect feeds on over 200 different plants. It may be found on beans, cucurbits, corn, potatoes, asparagus, cabbage, peas, beets, tomatoes, and turnips. It feeds on foliage and new shoots, leaving small holes in foliage. It also gnaws holes in fruit. This insect overwinters as a 1/4 inch long, yellowish-green beetle decorated with 12 black spots. The beetle's head and antennae are black. Females deposit eggs at the base of grass and corn plants. Adults are up to 3/4 inch long when full grown. These larvae, called corn rootworms, tunnel in the roots of plants. This tunneling action can result in severe stunting of corn plants and sometimes kills plants. There appears to be two generations per year.
Striped Cucumber Beetle
These 1/5-inch long beetles are yellow and are decorated with three wide black stripes. Striped cucumber beetles damage plants by feeding on leaves, stems, and fruit. They also carry the organisms that cause bacterial wilt of cucurbits and cucumber mosaic. Adults lay yellow eggs at the base of plants. Larvae, which are white and 1/3 inch long, feed on the underground parts of plants or on fruit that touches the soil. There are at least two generations per year. In addition to cucurbits, striped cucumber beetles feed on beans, peas, and corn. The most severe damage is caused to small plants.
Vegetable Weevil
Larvae and adults of this insect feed on foliage and exposed roots of potatoes, turnips, turnip greens, kale, and mustard greens. Late fall and early spring crops are most severely damaged. Adults are gray snout beetles 1/3 to 1/2 inch long. Two white markings on the rear half of the wing covers form a V shape. Eggs laid in the crowns of plants produce green, slug-like larvae. These grubs are about 1/2 inch long when full grown. This pest goes into a resting stage from June to September.
Wireworms
These beetles do the most severe damage to root crops such as Irish and sweet potatoes, although they injure other vegetables as well. There are many different species of wireworms. Adults are hard-shelled, dull colored beetles, ranging from 1/2 to 1-1/2 inches in length. Beetles are tapered toward both ends and appear streamlined. Adults are also known as click beetles because they snap and flip over when turned on their backs. They have a loose, flexible joint just ahead of the wings. Females lay eggs in the soil around the roots of grass plants. The eggs produce yellow to reddish-brown, tough-bodied larvae that are commonly called wireworms. Larvae range in size from 1/2 to 2 inches when full grown, and most are cylindrical and slender. Some wireworms are almost flat. Larvae feed on underground parts of plants. The pulpal stage is spent in the soil. It takes over a year to complete the life cycle of a wireworm. Wireworm damage is most severe on land not previously planted in row crops.
White Grubs
There are several species of these pests. Adults are hard-shelled, light brown to almost black beetles from 3/4 to 1 inch long. These insects are sometimes called May beetles and June beetles. They commonly feed at night on the foliage of trees and hide in the grass and lay eggs during the day. The spherical, pearly white eggs produce white C-shaped grubs with brown heads. Grubs feed on grass roots and other crops. The pulpal stage is spent in the soil. Among the common white grubs are the larvae of the green June beetle. Larvae feed mainly on organic matter in the soil. Grubs uproot young plants as they move about in and on the soil. Vegetables should not be planted in soil that was in sod the previous year until the soil has been treated to control white grubs as some grubs live two to three years.
White fringed Beetle
Among the many vegetables attacked by white fringed beetles are Irish potatoes, sweet potatoes, beans, and cabbage. Adults, which emerge in June and July, are dark gray beetles about 1/2 inches long, with a white margin or fringe on their sides. White, oval eggs are laid in a gelatinous mass on objects on or near the ground. Grubs are shite, legless, and 1/2 inch long when full grown. Grubs feed on the underground parts of many kinds of plants. The pulpal stage is spent in the soil, while the insect overwinters in the grub stage. There is one generation per year.
This Article is several days of research followed by another few days of writing. Hopefully this information will allow you to be careful and save your plants from insect damage. - Bird
All insect life cycles include an egg stage. The insect is immobile during this stage. A larva hatches from the egg. The larval stage is the growth stage and frequently the pest stage of insect life. This is especially true of moths, butterflies, and true flies. Larvae of moths and butterflies are commonly known as caterpillars. Maggots are the larvae of true flies. Many beetles exist as grubs during the larval stage. Larvae vary in size from as short as 1/8 inch to as long as 4 inches. The larva molts, or changes and enters the pupae stage. During the egg stage, the insect is immobile during this pupae period. It is during this stage that the insect develops into an adult. Adults may or may not feed in the same way and on the same plants as larvae. Beetles, for example, have chewing mouth parts and, like many grubs (beetle larvae), are capable of causing great damage to vegetables. Moths and butterflies, on the other hand, have mouth parts designed for siphoning and are unable to damage plants.
Incomplete metamorphosis consists of three developmental stages -- egg, nymph, and adult. The egg stage is similar whether an insect undergoes complete or incomplete metamorphosis. Immature insects called nymphs hatch from eggs. Nymphs damage plants and reduce vegetable quality by sucking plant juices. Some insects damage plants not only by extracting juice but also by injecting saliva into the plant. The best known example of this is the injury called hopper-burn caused by the potato leafhopper on Irish potatoes.
The pests discussed in this Article are divided into the following groups: Moths, Butterflies, and Their Young (Caterpillars); Beetles; Sap-Feeding Insects (True Bugs, Aphids, Leafhoppers, and Whiteflies); Flies; Other Insects; and Non-Insect Pests.
Moths, Butterflies, and Their Young
Caterpillars, the larval stage of moths and butterflies, damage both the foliage and fruit of a number of vegetables. These insects chew holes in foliage and fruit and leave degrading excrement and silk on plants.
Cabbage Looper
This caterpillar feeds on the underside of leaves of cabbage and related crops and on lettuce, spinach, beets, peas, and tomatoes. It chews irregular holes through leaves. Moths lay greenish-white eggs on the upper surface of leaves. Larvae, or worms, are 1-1/2 inches long when full grown. Larvae are pale green with four thin, white lines along the back and a wide, pale line on each side of the body. These lines can be seen easily, even on small larvae. The head is narrower than the thorax (body section behind the head). The larvae move in a measuring or looping motion, thus the insect's name. When disturbed, loopers rear upwards. Larvae go into a resting or pulpal stage in a flimsy, lace-like cocoon on the plant. The adult is a brown moth with silver markings on the wings. It has a wing spread of about 1-1/2 inches. There may be three or more generations per year, the number of worms increasing greatly with each generation. Cabbage loopers do not overwinter in The US. Moths from Georgia and Florida move into the state each year near the middle of May.
Beet Armyworm
Similar to the true armyworm, this insect is a general feeder and attacks foliage, stems, and sometimes roots of a wide variety of vegetables. Among plants attacked by this pest are beets, asparagus, corn, lettuce, cabbage, tomatoes, peppers, potatoes, onions, and peas. This pest is capable of destroying young plants. The beet armyworm overwinters as a pupa, emerging as an adult in the spring. The adult is a moth with a 1-1/4 inch wingspread. The moth's grayish brown front wings are marked with lighter lines and a spot near the center of the wing. Hind wings are white with brown edges and veins. Females lay between 500 and 600 eggs over a 4- to 10-day period. Irregular egg masses are covered with scales from the moth. Mature larvae are green with a prominent dark stripe along each side. Larvae have a dark spot on each side of the thorax, are 1-1/4 inches long, and pupate in the soil There are several generations a year.
Corn Earworm
(Also called Tomato Fruit worm and Bollworm)
This caterpillar feeds on a wide range of vegetables and, as a result, is known by several names. It may attack almost any vegetable but does the most serious damage to corn and tomatoes. Other vegetables attacked include peppers, eggplant, beans, okra, sweet potatoes, lettuce, and cabbage. Fresh corn silk is preferred by this pest as a location to deposit eggs. Eggs may hatch as soon as two or three days from the time they were deposited. Newly hatched larvae feed on buds and leaves or on corn silks. When they are four or five days old, larvae travel down the silks and feed on kernels at the end of the corn ear. If fresh corn silk is unavailable, moths prefer laying their eggs on tomato foliage, especially when plants are flowering. Larvae attack tomatoes from the time the fruit forms until it ripens, boring into the sides of the fruit and near the stem. Sometimes a small, black entrance hole is the only visible sign that a large worm is inside a tomato. Injury to tomatoes is most severe in the late summer and fall. When full-grown, larvae are about 1-1/2 inches long. They may be brown, green, or pink, with lighter colored longitudinal stripes. The head is yellow, and the underside of the body is always lighter than the back. Larvae enter the soil to pupate. Moths are cream to grayish-brown, have green eyes, and are marked with a dark spot near each wing tip. They have a wingspread of about 1-1/2 inches. Hind wings are light colored with darker areas near the edges. Moths deposit yellow eggs one at a time on plants. One female can lay as many as 3,000 eggs. There are usually three and sometimes a partial fourth generation of earworms each year.
Cutworm
Many kinds of cutworms attack vegetables. Asparagus, cabbage, squash, and tomatoes are particularly vulnerable. Most cutworms cut off stems of plants at or near the soil. Cutworms feed at night when temperatures are 65 degrees F or higher. During the day these insects hide just beneath the soil close to the site of the previous night's damage. This pest is capable of damage sufficient to necessitate the replanting of corn. Cutworms usually do not eat plants beyond cutting through them, although some species climb stalks and feed on the upper parts of plants, which causes less damage. When full grown, cutworms are 1-1/2 inches long. They curl up into a tight C shape when disturbed. Most cutworms are a dull color and have practically no hair. They pupate underground. Cutworms generally overwinter in the soil in the larval or pulpal stage. Adults are dull colored moths with wing spreads of 1 to 1-3/4 inches. Hind wings are usually light in color. Moths lay eggs on the stems of grasses and weeds or on bare ground. There may be more than one generation of some species each year.
Diamondback Moth
Larvae of this moth feed during the cool parts of the growing season on the underside of leaves of cabbage and related crops. Larvae feed for a time after hatching as leaf miners (see section on vegetable leaf miners). As larvae grow, they begin feeding on the external portion of leaves and buds. Feeding holes do not penetrate the entire leaf. Larvae are greenish-yellow with black hair and are about 1/3 inch long when full grown. They wriggle actively when disturbed and drop from the plant on silken threads. Larvae pupate inside a lacy cocoon attached to the leaf of the host plant. Moths overwinter in debris of collards, cabbage, cauliflower, and related crops. They have a wingspread of about 1/3 inch. Moths are gray to brown, marked with white. When at rest the moth has white, diamond-shaped markings along the back. The hind wings are paler and have a fringe of hair on the rear margin. Moths lay small, white eggs either singly or in groups of three or four on leaves. There may be five or six generations per year.
European corn borer
This borer attacks many species of plants, but corn, peppers, and Irish potatoes are the vegetables most severely damaged. European corn borers feed on leaves and in protected areas until about half-grown, when they bore into a plant's stem or fruit. Nearly an inch long when full grown, the caterpillar is cream colored, has a brown head, and is marked with small, round, brown spots. Caterpillars molt into pupae inside the host plant. This insect overwinters as nearly full-grown larvae in cornstalks at ground level. Adults are pale yellow moths with irregular dark bands running across the wings. The moth's wingspread is about 1 inch. Males are smaller and some-what darker than females. Eggs are laid in groups of up to 50 on the underside of leaves and overlap to resemble small fish scales. Most of the US sees at least two generations of this insect each year, while in the eastern part of the US, there are three generations most years.
Fall Armyworm
Like other armyworms, this insect may "march" from field to field. It often is called the shatter worm because of the destruction it causes to corn foliage. Larvae also damage corn ears as well as beans, potatoes, peppers, tomatoes, spinach, cabbage, and cucumbers. Swarms of moths move northward each spring from southern Florida and areas along the Gulf Coast. Females lay about 1,000 eggs each in masses of about 150. Eggs are usually laid on grass. Larvae are very small when they hatch but reach a length of 1-1/4 inches when full grown. Larvae vary in color from light tan to green or nearly black, are decorated with thin, yellow stripes, and have a prominent inverted white Y on the front of the head. Larvae go into the soil to pupate. Adult moths have dark gray front wings that are mottled with light and dark splotches. The wingspread of the adult moth is about 1-1/4 inches. Hind wings are grayish-white. Males have a white spot near each wing tip. It appears that this insect cannot overwinter in most of the US. Most years there are many generations of the pest.
Imported Cabbageworm
(Also called Cabbage Butterfly)
This caterpillar attacks cabbage, cauliflower, kale, collards, mustard, radish, and turnips. Larvae riddle outer leaves with irregularly shaped, often large holes. Caterpillars are capable of doing enough damage to severely retard plant growth. Females lay one egg per leaf on the underside of leaves. Eggs hatch into caterpillars that are 1-1/4 inches long when full grown. Caterpillars are velvety-green and are decorated with three indistinct gold stripes, one along the back and one on each side. The pulpal stage of the insect is brownish-grey and has many projections or spines. This insect is commonly found attached to a leaf during the pulpal stage. Glue at the pupa's tail and a silken loop that encircles the middle of the pupa's body hold it in place. The adult is a white butterfly with one or two black spots on each wing. This pest overwinters as a pupa either on old plant refuse or on nearby posts or buildings. There are three or four generations per year.
Pickleworm
Pickleworm larvae bore into many cucurbit fruits. Cantaloupes, cucumbers, and squash are most seriously damaged. Caterpillars feed first on foliage. As the insect grows, it begins feeding on fruit. Pickleworms do the greatest damage to growing vine tips and blossoms early in the season. Larvae are initially white with black spots and have dark heads. There is a dark indention on each side on the back of the head. Larger larvae are up to 3/4 inch long and are green. Sawdust-like excrement produced by larvae can easily be seen extruding from damaged fruit. Winter is spent in the pulpal stage in a silken cocoon on crop refuse in subtropical regions of the United States. Pickleworms usually appear in early July. The adult is a moth with a wingspread of about 1 inch. Wings appear fragile and are marked with pale yellow centers and yellowish-brown margins.
Potato Tuber worm
This caterpillar does significant damage feeding on exposed potatoes in the field, riddling them with narrow, silk-lined burrows. Adults are small, narrow-winged, grayish-brown moths with a wingspread of 1/2 inch. Moths tend to fly in late afternoon and evening. Females deposit single eggs on foliage of tomatoes, potatoes and related plants, or on exposed tubers of Irish potatoes. Eggs hatch into pinkish-white or green caterpillars with brown heads. When full grown, caterpillars are about 1/2 inch long. Larvae mature in about three weeks and pupate in gray, silken dirt-covered cocoons on the outside of the tuber. A brush of long dark scales protrudes at the end of the body. Moths deposit clusters of two to seven eggs on fruit, vines, buds, and leaves. There are at least four generations per year in The US. Cultural control is possible by planting for early maturity and destroying plants immediately after harvest, thus preventing movement of the pest to later crops. To prevent damage, potatoes should be kept covered with soil before harvest, and harvested potatoes should be stored in insect-proof areas. Also, vines should be cut, raked, and burned two or three days before harvesting. There may be several generations of this insect per year.
Squash Vine Borer
This borer can be very destructive to squash and pumpkin plants. By boring into a vine near the base, this thick, white, wrinkled brown-headed caterpillar causes entire plants to wilt. The larva overwinters 1 or 2 inches in the soil within a dark, dirt-encased cocoon and molts into a pupa in the spring. Within two or three weeks after molting, the 3/4-inch-long pupa has worked its way to the soil surface and emerged as an adult. The adult squash vine borer is a moth with a wingspread of about 1-1/2 inches. The front wings are covered with metallic, greenish black scales. Hind wings are transparent. The abdomen is ringed with red and black. Squash vine borer moths look and act like paper wasps. Females lay red eggs near the base of plant stems. Eggs produce smooth, white caterpillars that bore into the center of the vine a few days after hatching. Small piles of green excrement and wilting of whole vines are signs a plant is infested with squash vine borers. There are two generations of this pest each year. Damage is usually noticed in early June and again in early August.
Tomato Hornworm and Tobacco Hornworm
Tomato and tobacco hornworms feed on tomatoes, peppers, potatoes, and related plants. These green worms are 3 to 4 inches long and can defoliate young plants. Mature tomato hornworms can be distinguished by eight L-shaped, white markings along each side of the body and a bluish-black horn near the rear end of the insect. Tobacco hornworms are decorated with diagonal white bars and have a red horn. The white cocoons of a parasite are usually attached to the worm. Pupae of both species are mahogany brown and are found in the soil. In both species, adults are large, gray moths with mottled front wings. Hind wings are lighter. Two thin, zigzag lines run across the midsection of each hind wing of tomato hornworm moths. There is a dark area between these somewhat obscure lines on the wings of tobacco hornworm moths. On both species, five or six yellowish-orange spots can be found along each side of the body. Moths of both species have a wingspread of 4 to 5 inches and fly mainly around dusk. Females lay eggs individually on plants. Eggs are spherical and greenish-white. This insect overwinters as a pupa.
True Armyworm
This caterpillar is sometimes present in very high numbers. Armyworm epidemics can result in the destruction of large areas of vegetation. This pest attacks grasses, corn, and some legumes. Damage usually starts at the edge of a field. Larvae feed at night and may move in hordes. Armyworms are capable of consuming corn plants up to 8 inches tall. This insect stops feeding and overwinters as a partially grown larva. It resumes feeding in the spring. Armyworms are dark greenish-brown worms up to 2 inches long with white stripes down the sides and back. The insect pupates just below the surface of the soil.
Yellow striped Armyworm
This caterpillar is a daytime feeder. It is capable of doing significant damage to young tomato plantings, pepper fruit, and, occasionally in August, to sweet potatoes. Its presence is sporadic, however. Overwintering as pupae in the soil, yellow striped armyworms emerge as moths in the spring. Adults are brown, black, and white moths with a 1-1/2 inch wingspread. The moth's forewings are marked with a diagonal band that runs from the front to the rear of the wing and a smoky white stripe along the outside edge of the wing. Hind wings are white with a dark edge. Eggs, covered with scales from the female's body, are laid in clusters on foliage, trees, and buildings. Larvae are dark green with a yellowish-orange stripe along each side and black spots on their abdominal segments. There are several generations a year.
Beetles
Adult beetles are usually hard-bodied insects with thick forewings. The young are grubs, borers, or wireworms. Often adults feed on different host plants than do larvae, although both stages may be destructive to vegetables.
Asparagus Beetle
There are two beetle species that feed on asparagus -- the asparagus beetle and the spotted asparagus beetle. The spotted asparagus beetle (which is reddish-orange and black) is more destructive in asparagus production areas. Asparagus beetles are more troublesome in The US. The asparagus beetle is metallic blue with six yellow areas on the wing covers. Beetles are about 1/4 inch long and have a narrow, red head and thorax. This pest overwinters in protected areas and first appears each year in early April along the edges of fields. Adults gnaw tender asparagus buds and lay eggs on developing spears. Eggs are very dark, bullet like, and laid in rows. Processing plants sometimes reject otherwise edible spears because eggs have been laid on them. Eggs hatch within a week of the time they were laid. Sluggish, humpbacked, slate-colored larvae with black heads feed and grow on asparagus ferns for about 10 days. The pulpal stage is passed on the soil. A week or so after pupation, adults emerge and the cycle is repeated. There may be as many as five generations in a year. Asparagus is the only vegetable this insect attacks.
Bean Leaf Beetle
Adult bean leaf beetles range in color from red to yellow. The insect's markings may also vary, but bean leaf beetles generally have a dark triangular mark on the front of the wing covers, six black spots in the center of the back and a black edge around the outside of the wing covers. This insect is about 1/4 inch long and is long-lived. Adults will drop from foliage when disturbed. Bean leaf beetles feed on foliage, making round, and regular holes. This pest also attacks the stems of young plants at or slightly below ground level. Females lay eggs in the soil near the base of plants. From the eggs hatch slender, white larvae that feed on the roots of bean plants. Bean leaf beetles spend the winter as adults in trash near bean fields. There is one generation, possibly two, per year. Beans, peas, cowpeas, and soybeans are common host plants; however, this pest will also feed on corn, some clovers, and many weeds.
Blister Beetle
Several species of blister beetle feed on vegetables. The black, striped, and margined blister beetles are the most commonly seen. Blister beetles are slender, rather soft insects with a narrow thorax. The tip of the abdomen is exposed beyond the wing covers. Adults are black or gray and sometimes have narrow, yellow or gray stripes or edges on the wings. Adult beetles are ravenous feeders and are capable of destroying plants. The winter is passed as larvae in the soil. Larvae are about 1/3 inch long and yellow. Blister beetle larvae are beneficial in that they feed on grasshopper eggs. The pulpal stage also is spent in the soil. Adults emerge from the soil in midsummer and feed in groups for about five weeks. The beetle's body contains oil called cantharidin that causes blisters if the insect is crushed against tender skin. Yellow eggs are laid in holes in the soil in clusters of 100 or more. It appears there is one generation per year. Blister beetles will attack most types of vegetables but seem to prefer potatoes and tomatoes.
Colorado potato beetle
This insect is perhaps best known as the common yellow- and black-striped potato bug. This pest is, however, a beetle and not a true bug. Both adults and larvae feed on the foliage of potatoes. While potatoes are preferred, this pest also attacks tomatoes, eggplant, peppers, and horse nettle. Adults are about 3/8 inch long and 1/4 inch wide and very convex in shape. Black and yellow stripes run lengthwise along the insect's back. Females lay clusters of 20 or more yellowish-orange eggs on the underside of leaves. A single female beetle can lay over 500 eggs over the course of her four-week life. From the eggs come red, hump-backed, soft-bodied larvae decorated with two rows of black spots along each side of the body. Larvae begin chewing on leaves immediately after hatching. Larvae also feed on the fruit of tomatoes and eggplant. In two or three weeks larvae grow to a length of 1/2 inch, and then enter the soil to pupate. Seven days later adult beetles emerge from the soil, feed for a few days, mate, and lay more eggs. This insect overwinters as an adult in the soil. There are at least two generations per year.
Cowpea Curculio
This insect most commonly attacks black-eyed and Crowder peas. Adults are black, humpbacked snout beetles about 1/4 inches long. The adult female chews a hole in a pea pod and inserts an egg into the developing seed. This small puncture is difficult to see, and damage may go unnoticed until the crop is harvested. Eggs hatch into small, white, legless grubs with yellowish-brown heads. The grubs destroy the peas in a pod. There is at least one generation per year. Hot, dry weather appears to retard development of this pest. Adults overwinter in refuse around fields. Damage may be avoided by alternating from year to year the site where peas are planted.
Flea Beetle
The many different species of flea beetle attack a variety of vegetables. Species that attack potatoes, tomatoes, and eggplant are the most troublesome, but flea beetles also damage corn and sweet potatoes. Flea beetles are so named because of their enlarged hind legs and jumping ability. Adults are 1/16 to 1/18 inch long and usually black with brown legs and antennae. Eggs are laid in the soil at the base of plants. Larvae commonly feed on roots, often riddling them with tunnels or eating off rootlets. The pulpal stage is spent in the soil. These insects overwinter as adults in trash around field borders and in ditch banks. There are three or more generations per year. Round holes chewed in leaves are the most obvious damage caused by flea beetles. On small plants, this "buckshot" damage can result in plant death. On larger plants these feeding sites provide a good entrance for several blights and wilts.
Japanese beetle
These beetles are metallic green or greenish-bronze, 1/2 inch long with red wing covers, and are decorated with white spots near the tip of the abdomen. They commonly are found in June and July on fruit, deciduous trees, and vegetables. Japanese beetles also are frequent and persistent pests of sweet corn and beans. The insect spends the winter in the soil as a white grub about 3/4 inches long. Beetles emerge from the soil in midsummer and on warm, sunny days swarm to plants, where they eat the foliage, flowers, and fruit. Female beetles then return to grassy areas to lay their white, spherical eggs in the soil. Grubs feed on decaying vegetation and grass roots. Pupation occurs in the soil. There is only one generation each year.
Mexican bean beetle
The brown Mexican bean beetle is decorated with 16 black spots arranged in three rows across its back. Beetles are 1/3 inches long, convex, and resemble lady beetles. Adults overwinter on the ground among leaves and trash near fields where beans were grown. When warm weather arrives in the spring, they leave their overwintering sites and feed on beans for a week or two. Females lay lemon-colored eggs in groups of 25 or more on the underside of leaves. Eggs hatch about 10 days after being laid and yellow larvae with six rows of black-tipped, branched spines on their backs appear. Larvae, which are 1/3 inch long when full grown, feed for two to five weeks, and then enter the pulpal stage. The yellow pupa is attached to a leaf. Traces of the last larval skin can usually be found where the pupa is attached to the leaf. There are three or four generations per year. Both larvae and adults feed on leaves, usually on the underside. Damaged leaves have a skeletonized or lace-like appearance. Sometimes stems and pods are damaged. The insect attacks all kinds of garden beans, cowpeas, and soybeans.
Spotted Cucumber Beetles
(Also called the Southern Corn Rootworm)
In its adult form, this insect feeds on over 200 different plants. It may be found on beans, cucurbits, corn, potatoes, asparagus, cabbage, peas, beets, tomatoes, and turnips. It feeds on foliage and new shoots, leaving small holes in foliage. It also gnaws holes in fruit. This insect overwinters as a 1/4 inch long, yellowish-green beetle decorated with 12 black spots. The beetle's head and antennae are black. Females deposit eggs at the base of grass and corn plants. Adults are up to 3/4 inch long when full grown. These larvae, called corn rootworms, tunnel in the roots of plants. This tunneling action can result in severe stunting of corn plants and sometimes kills plants. There appears to be two generations per year.
Striped Cucumber Beetle
These 1/5-inch long beetles are yellow and are decorated with three wide black stripes. Striped cucumber beetles damage plants by feeding on leaves, stems, and fruit. They also carry the organisms that cause bacterial wilt of cucurbits and cucumber mosaic. Adults lay yellow eggs at the base of plants. Larvae, which are white and 1/3 inch long, feed on the underground parts of plants or on fruit that touches the soil. There are at least two generations per year. In addition to cucurbits, striped cucumber beetles feed on beans, peas, and corn. The most severe damage is caused to small plants.
Vegetable Weevil
Larvae and adults of this insect feed on foliage and exposed roots of potatoes, turnips, turnip greens, kale, and mustard greens. Late fall and early spring crops are most severely damaged. Adults are gray snout beetles 1/3 to 1/2 inch long. Two white markings on the rear half of the wing covers form a V shape. Eggs laid in the crowns of plants produce green, slug-like larvae. These grubs are about 1/2 inch long when full grown. This pest goes into a resting stage from June to September.
Wireworms
These beetles do the most severe damage to root crops such as Irish and sweet potatoes, although they injure other vegetables as well. There are many different species of wireworms. Adults are hard-shelled, dull colored beetles, ranging from 1/2 to 1-1/2 inches in length. Beetles are tapered toward both ends and appear streamlined. Adults are also known as click beetles because they snap and flip over when turned on their backs. They have a loose, flexible joint just ahead of the wings. Females lay eggs in the soil around the roots of grass plants. The eggs produce yellow to reddish-brown, tough-bodied larvae that are commonly called wireworms. Larvae range in size from 1/2 to 2 inches when full grown, and most are cylindrical and slender. Some wireworms are almost flat. Larvae feed on underground parts of plants. The pulpal stage is spent in the soil. It takes over a year to complete the life cycle of a wireworm. Wireworm damage is most severe on land not previously planted in row crops.
White Grubs
There are several species of these pests. Adults are hard-shelled, light brown to almost black beetles from 3/4 to 1 inch long. These insects are sometimes called May beetles and June beetles. They commonly feed at night on the foliage of trees and hide in the grass and lay eggs during the day. The spherical, pearly white eggs produce white C-shaped grubs with brown heads. Grubs feed on grass roots and other crops. The pulpal stage is spent in the soil. Among the common white grubs are the larvae of the green June beetle. Larvae feed mainly on organic matter in the soil. Grubs uproot young plants as they move about in and on the soil. Vegetables should not be planted in soil that was in sod the previous year until the soil has been treated to control white grubs as some grubs live two to three years.
White fringed Beetle
Among the many vegetables attacked by white fringed beetles are Irish potatoes, sweet potatoes, beans, and cabbage. Adults, which emerge in June and July, are dark gray beetles about 1/2 inches long, with a white margin or fringe on their sides. White, oval eggs are laid in a gelatinous mass on objects on or near the ground. Grubs are shite, legless, and 1/2 inch long when full grown. Grubs feed on the underground parts of many kinds of plants. The pulpal stage is spent in the soil, while the insect overwinters in the grub stage. There is one generation per year.
This Article is several days of research followed by another few days of writing. Hopefully this information will allow you to be careful and save your plants from insect damage. - Bird
