American Spider Beetle

American Spider Beetle Scientific Name: Mezium americanum

American Spider Beetle Identification

Forget what you thought beetles looked like. The American Spider beetle looks more like a spider than a beetle. That is probably why it’s called the “spider” beetle. It is tiny – only about an eighth of an inch long – and has a dull, pear-shaped yellow, gold, brown, or red body with glossy black elytra (hardened forewing). Its body and legs are cream-colored. Although the American spider beetle, like all insects, has six legs, when viewed from above the antennae look like a fourth pair of legs (hence the spider-like appearance).

American Spider Beetle Habitat and Food Source

The American Spider beetle resides in North and Central America and Australia. They are thought to have originated in Africa.

This beetle is most likely to be seen in homes, and is considered one of about 30 species of beetles that are serious pests indoors for their food foraging habits. American Spider beetles may also be found in warehouses and stores. The American spider beetle is adapted to living in dry environments and cannot fly because its forewings are fused and hardened. These insects often breed in deposits of bird, pet, and rodent feces. They are also commonly found breeding in bat roosts. If nesting in attics or crawl spaces of homes where bird or rodent feces may be present, the beetle will usually move toward food sources elsewhere in the house.

American Spider beetles are scavengers. They specifically feed on grains and insect matter inside grains, and may lay and hatch larvae inside stored products in warehouses and stores. American Spider beetles also eat vegetables, seeds, animal feed, tobacco, cayenne pepper, dead insects, paper, beans, you get the idea:  they eat everything.

American Spider Beetle Life Cycle

Female American Spider beetles lay about 40 eggs at a time, often inside stored foods. She spins a silken spindle-shaped cocoon out of which young beetles change into adults over the course of about three months. The American Spider beetle molts three times before its pupa stage. Larvae “hibernate” in the cocoon then emerge in the spring as fully grown beetles. On average, the American Spider beetle goes through one or two generations per year.

American Spider Beetles and Humans

The American Spider beetle is considered an extremely annoying pest and nuisance to humans and should be exterminated upon detection. Not only does this species damage food products and create an unsanitary environment for food, it can also inflict structural damage as it infests wall voids and ceilings. American Spider beetles are not known to bite humans, and rarely come in close contact with them, but will readily enter areas where food is stored. American spider beetles are nocturnal therefore forage at night and are not often seen by humans.

American Spider Beetle Control

A professional will locate nesting sites and food sources of the American spider beetle first, then set to work eliminating both. It is most advisable to employ professional help as infestations are commonly very widespread.

1. Find out where the beetles are coming from: It is important to locate any bird, pet, rodent, or bat feces that may be the source of infestation. These must quickly be eliminated. Discard any trash, food products, even decorations that have been infested.
2. Insecticides: Most professionals will focus efforts on cracks and crevices in walls, ceilings, drawers, shelves, and other infestation sites. Exterminators most commonly use a compound known as a pyrethoid.
3. 3.       Dust pesticides are applied to penetrate wall voids on other difficult to reach places.

 DIY and Green Solutions for American Spider Beetle Control

Some small infestations, especially those that are caught early, may be able to be controlled using some do-it-yourself methods, but with this particular pest you are probably safest contacting a professional. Whether or not you employ professional services should be dependent on the scope of your American spider beetle problem. Keep in mind that the root of the problem may be another pest like rodents, birds, or bats and they should be eliminated first. Contaminated and infested foods should also be thrown out immediately.

1. Find out where the beetles are coming from: This is meant literally, not figuratively. It is important to locate any bird, pet, rodent, or bat feces that may be the source of infestation. These must quickly be eliminated. Discard any trash, food products, even decorations that have been infested. The American Spider beetle may be specifically attracted to moist areas, so focus on cleaning and drying any moist areas of your home.
2. Tidy Up!: Remove all clutter from your home. Clean any cabinets and shelves where contaminated food products were stored. Vacuum all infested areas then wash them with soap and water. Keep dried goods like cereals, rice, birdseed, and pasta in containers with close-fitting lids. Grains stored for long periods of time are most likely to be infested, so use older products before buying a significant amount of newer ones.
3. Insecticide:  Though not a “green” solution, insecticides are effective in controlling beetle populations. Pyrethoids have proven effective against the American spider beetle, but only after all breeding and nesting sites have been identified and eliminated.

American Spider beetles are relentless pests that, once in your home, are there to stay unless you take measures to get them out. Professional extermination is the best bet for getting rid of this pest. With this particular species, there is usually an underlying cause of the beetle infestation, which can be the most difficult part of extermination. Seek out the source of the infestation, then call a professional or try some do-it-yourself methods to get rid of the buggers.