Pantry Pests

 
Cigarette Beetle & Drugstore Beetle
cigarette_and_drugstore_beetle.jpgDescription: Adult cigarette beetles are yellowish to reddish brown, oval-shaped, and about 1/10 inch long. The head is bent downward sharply, giving the body a humpbacked appearance when viewed from the side. The wing covers (elytra) are smooth. The antennae are uniformly serrate (saw-like).
 
Adult drugstore beetles are reddish brown, more elongate, and about 1/10 inch long. The head is bent downward but does not result in a distinct humpbacked appearance. The wing covers are striated (faint lines running lengthwise). The antennae have three enlarged segments at the tip. 
SymptomsCigarette beetles commonly infest dried tobacco and tobacco products. They also infest raisins, figs, dates, ginger, pepper, nutmeg, chili powder, curry powder, cayenne pepper, paprika, 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 have been known to damage the leaves and bindings of books when feeding on the paste and overstuffed furniture when infesting the stuffing (hair, straw, etc.).
 
Drugstore beetles will feed on many drugs, including poisonous substances such as belladonna and strychnine. They infest almonds, peanuts, paprika, red pepper, alfalfa meal, cornmeal, flour, milo, wheat, wheat bran, wheat germ, dry dog food, bread, beans, coffee beans, fish meal, spaghetti, instant chocolate, powdered milk, books and manuscripts, dried flowers, and certain fillers and fabric coverings of furniture.
 
Life Cycle: Both beetles can live from two to four weeks, and during this time, females can lay 30 to 100 oval, whitish eggs in foodstuffs. The eggs hatch in 7 to 20 days. Larvae reach maturity in 30 to 50 days, and then pupate in a silken cocoon covered with bits of the material on which they fed. The pupal period is 8 to 10 days long. The life cycle can be completed in 40 to 50 days under ideal conditions. There are usually three to six generations of cigarette beetles and one to four generations of drugstore beetles each year. The beetles can fly but usually hitchhike in infested materials distributed by man.
 
Larvae of both species are C-shaped grubs about 3/16 inch long when mature. 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. 

Rice Weevil

rice_weevil.jpgDescription: Adult weevils are about 3/32 to 1/8 inch long (2-3mm). The adult rice weevil is a dull reddish-brown to black with round or irregularly shaped pits on the thorax and four light reddish or yellowish spots on the elytra (wing covers). The adult weevil can fly and is attracted to lights. The larval stage is legless, humpbacked, white to creamy white, with a small tan head. The maize weevil is very similar to the rice weevil, but larger.

Habitat: Rice weevils are usually found in grain storage facilities or processing plants, infesting wheat, oats, rye, barley, rice, and corn. Although not often found in the home, they are sometimes found infesting beans, birdseed, sunflower seeds, dried corn, and too a lesser degree macaroni and spaghetti. Rice weevils do not bite, nor do they damage wood or furniture.

Life Cycle: The adult female rice weevil lays an average of 4 eggs per day and may live for four to five months (producing 250-400 eggs). A single generation can be completed in around 28 days. The eggs hatch in about 3 days. The larvae feed inside the grain kernel for an average of 18 days. The pupal stage lasts an average of 6 days (5-16 range). The new adult will remain in the seed for 3 to 4 days while it's cuticle hardens and matures. 

Sawtoothed Grain Beetle

sawtoothed_grain_beetle.jpgDescription: The adult is a small, active, brown beetle, 2-3mm long, with a flattened body and six saw-toothed projections on each side of the thorax. The larva is yellowish-white, about 2-3mm long, with a brown head. The abdomen tapers toward the tip.

Habitat: The sawtoothed grain beetle is one of the most widespread of all stored-product pests and can originate at the manufacturing, storage or retail levels. They may occur in both food products in the pantry area as well as in other adjacent rooms. Foods that may be infested include cereals, flour, pastas, dried fruits, dried meats, candies, and other similar packaged goods. As with other pantry insects, it is the larvae do most of the damage, yet it is the adult that is most commonly encountered. The adult can readily enter sealed cardboard boxes and soft plastic packages.

Life Cycle: The adult beetles usually deposit their eggs in the food stuffs they infest. A single female can lay from 45 to 250 or more eggs which hatch in 3 to 17 days depending on the temperature. The larva is yellowish white with a brown head and measures 1/8 of an inch in length when fully grown. The larval period lasts from 2 to 10 weeks after which they pupate by sticking together small bits of the food material to form a protective covering around their bodies. The pupal stage lasts from one to three weeks after which the new adults emerge. The adults are long-lived and have been kept alive for over 3 years. Under ideal conditions the life cycle is completed in about 30 days.