William F. Lyon
|Common Name||Scientific Name|
|Cigarette Beetle||Lasioderma serricorne (Fabricius)|
|Drugstore Beetle||Stegobium paniceum (Linnaeus)|
Both cigarette and drugstore beetles infest a wide variety of foods, especially dried plant and animal products. In addition to being common stored-product pests, these beetles also become a homeowner nuisance by flying on windows and doors in heavy populations. Cigarette beetles may feed on pyrethrum powder strong enough to kill cockroaches, and drugstore beetles often feed on poisonous rodent baits containing strychnine. They also may chew through furniture fabric, books, manuscripts, and similar materials. They do not bite or sting humans or pets, spread disease, or feed on or damage the house.
Adult cigarette beetles are yellowish- to reddish-brown, oval-shaped, and about 1/10-inch long. The head is bent downward sharply, nearly at right angles to the body, giving a humpbacked appearance when viewed from the side. The wing covers (elytra) are smooth, and the antennal segments are uniform and saw-like (serrate). Adult drugstore beetles are reddish-brown, more elongated, and about 1/10-inch long. The head is deflexed, but does not result in a distinct humpbacked appearance. The wing covers have faint lines running lengthwise (striated), and the antennae have three enlarged segments at the tip. Eggs of both beetles are pearly white, and are not easily seen with the naked eye. When fully grown, both beetle larvae are C-shaped (grub-like) and about 3/16-inch long. Cigarette beetle larvae are creamy white and covered with long, yellowish-brown hairs. They have a brown head and legs. Drugstore beetle larvae are similar but do not have the fuzzy appearance.
|Cigarette Beetle: Adult, Side View, Larva|
|Drugstore Beetle: Adult, Side View, Larva|
Female cigarette beetles lay about 30 eggs in a period of 3 weeks. Eggs hatch in 6 to 10 days. The larval stage lasts from 5 to 10 weeks with larvae shunning light. The pupal and prepupal periods last 2 to 3 weeks and are passed in a cell. The life cycle lasts from 70 to 90 days, and there may be 5 to 6 overlapping generations per year in warm localities with only one generation in the more temperate regions. Adults are strong flyers and active in subdued light at temperatures above 65 degrees F. Adult beetles may live from 23 to 28 days. In temperate climates, beetles begin swarming in May and again in August. Overwintering may be passed in the larval stage, with some adults not too resistant to cold hibernating in crevices. In warehouses, the life cycle may be completed in 52 days.
Female drugstore beetles lay eggs singly in foodstuffs. The larval period ranges from 4 to 5 months, with the pupal stage lasting from 12 to 18 days. The complete life cycle requires 7 months. Larvae form a little round ball or cell which becomes its cocoon, and in which it pupates. Some have succeeded in rearing the beetle from egg to larvae in 2 months, with 4 broods per year in warm summer months. In cool climates, there is one generation per year.
Cigarette beetles commonly infest dried tobacco and tobacco products - hence their name. They also infest raisins, figs, dates, ginger, pepper, nutmeg, chili powder, curry powder, cayenne pepper, paprika, yeast, drugs, legume seeds, barley, cornmeal, flour, soybean meal, sunflower meal, wheat, wheat bran, rice meal, beans, cereals, fish meal, peanuts, dry yeast, dried flowers, leather, woolen cloth, and bamboo. They also may damage the leaves and bindings of books when feeding on the paste, or overstuffed furniture when infesting the straw, hair, etc.
True to their name, drugstore beetles feed on many drugs in the pharmacy, such as laxative teas and even strychnine. They also infest almonds, peanuts, paprika, red pepper, alfalfa meal, cornmeal, flour, milo, wheat, wheat bran, wheat germ, dry dog and cat food, bread, birdseed, beans, coffee beans, fish meal, spaghetti, instant chocolate, powdered milk, books, manuscripts, dried flowers, certain fillers and fabric coverings of furniture, leather, museum specimens, and other foodstuffs.
The simplest and most effective control measure is to locate the source of infestation and quickly get rid of it. Use a flashlight or other light source to examine all food storage areas and food products carefully. Dispose of heavily infested foods in wrapped, heavy plastic bags or in sealed containers for garbage disposal service, or bury deep in the soil if practical and regulations allow. If the infestation is detected early, you may solve the problem.
At the time of purchase, carefully examine foods such as pancake flour, flour, cornmeal, raisins, dry dog and cat food, old tobacco, ginger, dates, red pepper, rice, and macaroni. Check the packaging date to establish freshness. Examine broken and damaged packages and boxes to avoid bringing these stored-product pests accidentally into the home. Purchase seldom-used foods in small quantities to prevent storage periods of one month or more, especially during the warm summer months. Store susceptible foods in insect-proof containers of glass, heavy plastic, or metal, ideally with screw-type lids, or store in a refrigerator or freezer. Use older packages before new ones, avoid spillage in cabinets, and always keep food-storage spaces clean. Properly ventilate the storage area to discourage these moisture-loving pests.
Lightly infested or suspect foods with questionable infestations can be heated in a shallow pan in the oven at 120 degrees F for 1 hour or at 130 degrees F for 30 minutes; placed in a deep freeze at 0 degrees F for 4 hours; or heated in a microwave oven for 5 minutes. Heat-treat dried fruits or vegetables by placing in a cheesecloth bag and dipping in boiling water for 6 to 10 seconds. Seeds saved for planting may have the germination reduced by super-heating or cooling. Sifting the food material will remove possible insect fragments, and any remaining will not cause harm if consumed. After insects are killed, contaminated food might be used outdoors during the winter months for bird feed.
Careful sanitation is the best method to avoid stored-product pests. After removing all food, food packages, utensils, dishes, etc. from the cupboard, shelves, or storage area, use a strong suction vacuum cleaner with proper attachments to clean all spilled foods (cornmeal, toaster crumbs, bits of pet food, raisins, etc.) from the cracks and crevices behind and under appliances and furniture. Pull out heavy appliances from the wall and scrub with soap and hot water. The ability of these insects to find a small amount of food is amazing. After shelves are thoroughly dry, cover with clean, fresh paper or foil before replacing with food or cooking utensils. Pheromone trap/lures are commonly available from: Insects Limited, Inc., 10540 Jessup Blvd., Indianapolis, IN 46280. The phone number is: 1-800-992-1991.
The use of insecticides is discouraged around food materials. Insecticides are supplementary to sanitation and proper storage. Household insecticides have no effect on insects within food packages. For extra protection, some treat seeds or grains before storage with dusts or sprays of synergized pyrethrins labelled for this use. (Follow label directions and safety precautions.) If the problem becomes severe and widespread, contact a reputable, licensed pest control operator who has the training, experience, equipment, and insecticides to get the control job accomplished safely.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-6181