Kitchen shelves and pantries provide a welcoming environment for many small insect species. Undisturbed packages of grains, fruits, meats and cheeses are a food source for adult insects and developing larvae. Food may become contaminated as it sits on the grocery store shelf. You may not notice these moths, beetles or weevils until after you have brought the food into your home
Carpet beetles, cabinet beetles and larder beetles belong to the Dermestid beetle group. Adult beetles measure 1/8 to 1/4 inch and have scaly or hairy multicoloured bodies. The larvae are scavengers that feed on stored animal and plant products in the kitchen. They measure up to 1/4 inch long and have long hairs protruding from their reddish-brown bodies. Cabinet beetle larvae feed on cereals and other stored grain products. Carpet and larder beetle larvae prefer animal products, such as meat, cheese or dead insects. Both adult and larval carpet beetles will feed on food that has spilt into crevices.
Grain weevils, such as the granary weevil and rice weevil, infest stored whole grains. The adults eat the outside of the grain kernel and lay eggs in the inner part of the kernel. The white, wormlike larvae hatch four weeks later and feed on the inside of the kernel. An adult weevil measures about 1/8 inch long and has a long snout. Granary weevils are dark brown or black and wingless. Rice weevils, which have wings, have dark red or black bodies with four reddish or yellow spots on the wing covers.
Indian Meal Moth
If your stored flour, birdseed, candy or dried fruit contains fine webs or clumps, the Indian meal moth may be present. This moth has a 3/4 inch wingspan with grey and copper wings. The legless, greenish- or pinkish-white larvae measure up to 1/2 inch long. According to the North Dakota State University Extension, an infestation often originates in dry dog food. A few days after the female lays eggs in stored food, the larvae hatch and begin to feed on and spin webs in the food.
Sawtoothed beetles and confused flour beetles are also known as bran bugs. These beetles and their larvae feed on cereals, seeds, rice, dried fruits and other plant products. Adult beetles can chew through boxes and other food packaging. According to the University of Nebraska Cooperative Extension in Lancaster County, bran bugs are among the most common insects in the pantry. The adult sawtooth beetle, which measures 1/10 inch long and has a flat, elongated brown body, lays its eggs in food. Three to five days later, the whitish larvae hatch and develop inside the food. The confused flour beetle, which has similar habits, has a reddish-brown body with ridged wings.
Store flour, rice and other foods in airtight glass, metal or plastic canisters. Cardboard boxes or plastic bags are not suitable, because some insects can penetrate these containers. Regularly clean shelves and crevices in cupboards. To salvage lightly infested foods, The University of Nebraska Extension recommends heating the food product in an oven for 60 minutes at 60 degrees Celsius. Before spraying with pesticides, remove contents from the shelves. Spray lightly with pesticides labelled for indoor use, and allow the spray to dry before placing food on the shelves.