Beetles are everywhere. Not only are they all over the world, but they are also found in deserts, rain forests, mountains, and even on the ocean floor.
Many species of beetles have evolved to become masters of disguise with their colors and patterns. Their ability to blend into their surroundings makes them difficult for predators to spot.
This list is not exhaustive but it does include some of the most common species that people may run into when visiting their local forest or backyard.
ASPARAGUS BEETLES
Asparagus Beetle – Larva and Adult
There are two species of beetles that attack and cause economic damage to asparagus.
They are the common asparagus beetle, Crioceris asparagi (Linnaeus), and the spotted asparagus beetle, Crioceris duodecimpunctata (Linnaeus).
The common asparagus beetle is the more widespread of the two species.
COMMON ASPARAGUS BEETLE:
DESCRIPTION
The common asparagus beetle is 1/4 inch in length, has a bluish-black head, legs, and antennae tinged with the green, reddish thorax and the wing covers are marked by yellowish patches and reddish borders. The larva or grub of this beetle is dark gray to olive green with black legs and head.
INJURY
Both the larvae and the adults of the common asparagus beetle damage the asparagus plants. The overwintered adults emerge and begin to feed on the tender growing tips of newly sprouted asparagus. They eat out holes and cause a brownish discoloration of the tissue. The grubs will feed on the tender young tips and foliage. The plant growth is seriously reduced and proper root development is prevented causing a decrease in the size and quality of the crop.
LIFE HISTORY
Adult beetles overwinter in sheltered places such as piles of rubbish and heaps of old asparagus tops. They emerge from their shelter when the new shoots come up and begin feeding on the tender tips. They soon lay eggs on the young shoots. The eggs are elongate, oval, and deposited either singly or in rows of two to eight. Later in the season, the eggs are laid on leaves and flower stems.
The eggs hatch in 3 to 8 days and the grubs begin feeding on the tender tips. When the grubs mature, they drop to the ground and construct a small earthen cell where they transform into pale yellowish pupae. The adult beetles emerge from the pupae. There may be two or more generations a year depending on the climate.
SPOTTED ASPARAGUS BEETLE
DESCRIPTION
The spotted asparagus beetle is slightly larger and more robust than the common asparagus beetle.
The adults are reddish-orange with black antennae, eyes, and underside of the thorax. Each wing cover has six distinct black spots.
INJURY
This beetle is most injurious in the early season when the adults attack the growing tips and sometimes eat the buds of newly sprouted asparagus. The beetles also feed on foliage eating out irregular areas. The larvae cause little damage because they feed inside the berries.
LIFE HISTORY
The adult beetles overwinter in piles of debris. They leave their winter quarters about one week later than the common asparagus beetles and begin to feed on the tender young shoots. They do not deposit eggs until the plant begins to blossom, about three weeks after they’ve emerged. The egg is deposited singly on plants, usually those bearing fruit.
The egg is 1/25 inch in length, olive-brown, and attached to the leaf by one side. The grubs hatch in 7 to 12 days and are yellowish-orange in color with a black head and legs. The larva finds a berry and enters it at the blossom end.
Inside the berry, it feeds on the seeds and it may attack 3 or 4 berries before it is mature. When fully grown, it drops to the ground by a silken thread and spins a cocoon just under the soil surface.
MANAGEMENT
Cutting the shoots very clean and just below ground level every day or two during the cutting season will tend to remove the eggs of the common asparagus beetle before the larvae can establish themselves in a home garden patch. In small gardens gathering and destroying of the asparagus, berries will help to give control of the spotted asparagus beetle.
BLISTER BEETLES
Injury
Several species of blister beetles (“old-fashioned potato bugs”) feed on the foliage, buds, flowers, and fruits on a large number of plants.
They feed on many vegetables including beans, beet, cabbage, cowpea, corn, carrot, eggplant, melon, onion, pea, pepper, potato, pumpkin, radish, spinach, sweet potato, Swiss chard, and tomato. They also feed on young trees, vines, ornamentals, flowers, forage crops, and many weeds.
Only adults feed on the plants, but they are very voracious and can cause serious damage. Blister beetles are so named because their bodies contain an oil known as cantharidin which can blister skin if crushed on it.
Description
These insects are long, up to 3/4 inch, and are slender beetles with the prothorax narrower than the soft wing covers. Depending on the species, they are grey to black or have yellowish-white or grey longitudinal stripes.
They overwinter as a pseudopupa, enter a pupal stage in the spring, and emerge as an adult in swarms in late June or July, feeding on plants. Eggs are laid in clusters that hatch into strong-jawed larvae that eat grasshopper eggs.
The larvae molt four times, going through a series of changes in form. After the last molt, they enter the soil and turn into the hard-shelled, immobile pseudopupa for the winter.
Nonchemical Control
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- 1. In small infestations, pick off beetles and place them in a jar of kerosene. Wear a glove to keep from getting blistered.
- 2. Valuable plants can be covered with fine-mesh netting.
- 3. Controlling grasshoppers will reduce the blister beetle population.
Chemical Control
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- 1. Blister beetles are difficult to control with insecticides. Thorough coverage of the foliage will be of benefit
- 2. Recommended insecticides include methoxychlor, Rotenone.*
- 3. Read and follow all label directions. Observe the proper number of days to wait before harvest for each particular crop.
CIGARETTE AND DRUGSTORE BEETLES
DESCRIPTION
These two small beetles have become common household pests. The adult beetles may be seen at various times of the year, often in early summer.
They are good fliers and may accumulate on window or door sills when they try to make their way out of doors.
The cigarette and the drugstore beetle are very similar in appearance. Both are small, about 1/10 inch in length, reddish-brown oval-shaped beetles. The cigarette beetle has the head bent down nearly at right angles to the body giving it a humped back appearance when viewed from the side.
The drugstore beetle has the head deflexed, but not quite as much as the cigarette beetle. To distinguish between the two species, you will need to look closely at the antennae. The drugstore beetle has a distinct three-segmented antennal club, while the cigarette beetle does not have a distinct club.
The larvae of both are about 1/6 inch long when full-grown, whitish with the head dark brown to tan. Larvae are found in foodstuffs.
INJURY
Besides the nuisance factor of having beetles in the house, both species are considered stored food product pests. The cigarette beetle (Lasioderma serricorne) is destructive to cured leaf tobacco and tobacco products (especially those in storage) but also feeds on dried yeast cakes, seeds, dried botanical specimens, dried fish, leather goods, and even tapestry and upholstered furniture.
The drugstore beetle (Stegobium paniceum) feeds on almost anything of vegetable origin including a great variety of stored foods, seeds, breakfast cereals, and the like. It gets its name from the habit of feeding on almost all drugs found in pharmacies. Both species are often found infesting herbs and spices in the home, especially those that have been left on the back of a shelf in storage for long periods.
Condiments such as dried chili powder, hot peppers, and celery seed are a few of the items in which they are found. Also, such items as dried flower arrangements of seed pictures may harbor an infestation.
LIFE HISTORY
The adult beetles live from 2 to 4 weeks and during this time the females may deposit as many as 100 eggs. The eggs are often laid singly in foodstuffs. The larval period usually ranges from four to five months, but under very favorable conditions the development from egg to adult may occur in 6 to 8 weeks. When the larvae are fully grown, pupation occurs and they remain in this resting stage for 12 to 18 days. Here, in the Northeast, there is usually only one generation per year.
MANAGEMENT
Carefully examine all susceptible food and articles in the kitchen, pantry, or other rooms where you find the beetles. Look for the beetles themselves and the fine powder they leave after having fed. When the source of the infestation is found it should either be discarded or an effort made to eliminate the pests. In the case of a container of herbs or spice, discarding may be the most practical method of control. With a dried flower arrangement, it may be possible to use an insecticide to eliminate these insects.
In the closet or cupboard contents from nearby containers of susceptible products should be examined. If you are not sure of the status, transfer the contents to glass jars with tight-fitting tops. This is a good precaution because the eggs of the beetles, concealed in the product when the examination was made, may hatch later and lead to new infestations. Glass jars aid the viewer in a periodic examination of the food.
Food products stored over long periods often end up with an infestation. If possible, products should be purchased in quantities suitable for early use, or adequate containers should be employed. A household spray for crawling insects may be used to help control infestations of beetle accumulating on windowsills or door sills. Removing and cleaning up the source of the infestation is the best way to avoid future infestations and keep these insects under control.
FLEA BEETLES
INJURY
Adult flea beetles feed on the leaves of cabbage, tomato, tobacco, potato, cucumber, melon, grape, spinach, eggplant, and related crops.
They chew many holes in the leaves and a heavily infested plant may look as if a small shot had been fired into it.
The foliage may be very badly eaten on many garden plants causing the plants to die. Larvae feed on the roots and tubers of the host plants. In most cases, different kinds of flea beetles attack only closely related plants, but some are general feeders.
DESCRIPTION
The adult flea beetle is small – 1/16 to 1/5 inch long, oval in shape, and it varies in color from blue-green to black. These small jumping beetles have the hind femora enlarged. The larvae are delicate, whitish, slender cylindrical worms, not over 1/3 inch long with brownish heads and long legs.
LIFE HISTORY
After mating in the late spring, the female beetle enters the soil near the base of the food plant to lay her eggs. The eggs hatch in 5 to 8 days.
The larvae feed on the roots for 2 to 3 weeks. When the larvae are mature they enter the inactive pupal stage for 10-14 days. Adults emerge and a second-generation begins and sometimes even a third. The insect overwinters as an adult in the soil and emerges again in May or June to begin feeding on the next season’s crops.
MANAGEMENT
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- 1. Keeping down weeds on which the flea beetles may live in and around the garden is one way to keep them in check.
- 2. The insecticides carbaryl (Sevin), diazinon, methoxychlor, or rotenone are effective against these beetles on most vegetable crops. Other insecticides may be labeled for specific crops. Before using any pesticide, be sure to check the label to see if the crop you want to treat and the pest you want to treat for are on the label.
- 3. Physical barriers such as row covers may help to protect plants from early damage. Row covers should be put in place when transplants are set or seeds are sown. Row covers should be removed before temperatures get too hot in mid-summer (often after 4 to 6 weeks).
- IF NOT, DO NOT USE THE PRODUCT.
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- 4. Treatment should begin as soon as the first flea beetle appears.
- 5. Be sure to follow manufacturers’ directions when using any chemicals or pesticides.
LADY BEETLES
(Family: Coccinellidae)
DESCRIPTION and PROBLEM
Lady beetles, also commonly known as ladybugs or ladybird beetles, frequently become a nuisance in homes during the winter and early spring.
They are the familiar, small, hemispherical beetles generally reddish-orange, tan, or yellow usually with black spots. The two-spotted lady beetle, Adalia bipunctata, is a common species in this area. It is orange-red with one black spot on each wing cover.
In the fall the adult beetles congregate in protected spots to hibernate over the winter. In many cases, they find their way into the home for this purpose. Normally the beetles remain inactive throughout the cold winter months living on stored fat. However, in some homes, they may be sufficiently warmed to become active.
When this happens they are attracted to windows, especially those on the sunny side of the house, in an attempt to get outside. Activity increases with the return of warmer temperatures in the spring and during warm sunny periods during the winter. They may occasionally be found feeding on a source of sweet fluid such as plant secretions, cut fruit, or sugar syrups.
They do not cause much damage to foodstuffs or plants but are merely seeking a source of moisture and food. The beetles can leave a yellow stain on hands or fabrics if crushed or disturbed.
Before the homeowner takes serious action against ladybugs, he or she should be aware of their importance.
Ladybugs are beneficial insects, important in the biological control of several serious insect pests. Both the adult beetles and the larvae feed upon aphids, scale insects, and mealybugs that are serious pests of fruit trees, vegetables, and flowers.
Several species of ladybugs are collected and sold to growers for control of insect pests. Because of their important role in insect pest control, ladybugs should not be wantonly destroyed.
If they become a serious household nuisance, they may be eliminated by spraying or dusting their bodies with household formulations of malathion or another household spray for crawling insects or by spraying with pyrethrum aerosol spray. They may also be collected with a vacuum cleaner.
Be sure to empty the bag after vacuuming up insects (or they may come out in the storage closet). The beetles will disperse outside when warmer temperatures return in the spring in search of prey and egg-laying sites. They should no longer be a problem in the household during the summer.
SAP BEETLES
INJURY
Sap beetles bore into fruits about picking time, and are especially attracted to overripe fruits. They are more destructive on tomatoes where the beetles bore into the fruit through cracks or any damaged area on the tomato fruit.
In table corn, sap beetles are particularly noticeable on ears where there has been bird damage or where corn borers or corn earworms have been feeding. In the cornfield, if they are plentiful, they may enter by the silk on previously undamaged cobs. The sap beetles do not do the primary damage but feed on the sap exuding from damaged tissue. They do not bite or sting.
In some instances, these beetles have caused severe damage by contaminating fruit and vegetables especially raspberries, tomatoes, and table corn. Most sap beetles are found where to plant fluids are fermenting or souring as they are attracted to the odors of such things as ripe fruit, prepared food, soft drinks, alcoholic beverages, and fresh paint.
DESCRIPTION
Most sap beetles are small, 12 mm in length or less, and generally elongate or oval. Members of this family vary considerably in size, shape, and habits. Our most common sap beetle is also called the picnic beetle and the four-spotted sap beetle is a small dark beetle about 1/4 inch long with two yellow spots on each wing cover.
MANAGEMENT
Populations around homes and picnic areas are difficult to control. A spray of either the insecticide carbaryl (Sevin), Baygon, or malathion to lawns or picnic places will reduce the number of beetles present. However, food odors will attract more beetles from surrounding places.
Fruits should be picked and moved from the field as soon as possible to prevent overripening. Unmarketable fruits should be discarded rather than leaving them on the ground. If beetles are plentiful, a spray of malathion may be tried. Malathion may be applied within one day of harvest.
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