Alphitobius

Pronunciation

How to pronounce Alphitobius: //ælˈfɪtoʊˌbaɪəs//

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Summary

Alphitobius diaperinus, commonly known as the lesser mealworm or litter beetle, is a cosmopolitan pest insect primarily affecting poultry facilities and stored grains. Known for its distinctive shiny appearance and potential health risks, it serves both as a nuisance in agriculture and, in certain contexts, as a source of feed and human food.

Physical Characteristics

The adult lesser mealworm beetle is roughly 6 mm long and widely oval in shape. It is shiny black or brown with reddish brown elytra, variable in color among individuals and changing with age. The body surface is dotted with puncture-like impressions, and the antennae are paler at the tips with tiny, yellowish hairs. The elytra have shallow longitudinal grooves. Larvae resemble other mealworms but are smaller, measuring up to 11 mm long when mature, tapering and segmented with three pairs of legs toward the front end, and initially whitish, darkening to yellow-brown as they mature.

Identification Tips

One can identify Alphitobius diaperinus by its shiny black or dark brown coloration, oval shape, and the distinctive reddish brown elytra. The presence of shallow longitudinal grooves on the elytra and the punctured appearance of the body surface are also helpful identification features. Additionally, larvae can be distinguished from other mealworms due to their smaller size and different coloration stages.

Habitat

Lesser mealworms thrive in warm, humid environments, often found under loose bark, in tree holes, caves, rodent and bird nests, grain processing and storage facilities, and poultry housing and litter.

Distribution

This species has a cosmopolitan distribution, known to occur nearly worldwide. It may have originated in Sub-Saharan Africa and was likely introduced to North America from Europe.

Diet

The beetle consumes a variety of organic materials, including litter, bird droppings, bat guano, mold, feathers, eggs, carrion, and the eggs and larvae of other insects. It is known to engage in cannibalism and can affect sick or weakened live animals.

Life Cycle

The adult female lays approximately 200 to 400 eggs, sometimes producing up to 2000 eggs throughout her lifetime. The larvae emerge within a week and take 40 to 100 days to reach maturity. Typically nocturnal, both larvae and adults become most active at dusk. Pupation occurs alone in secure spots after reaching maturity across 6 to 11 instars.

Reproduction

The female beetle lays her eggs in litter, droppings, grain stores, or cracks in structures every few days throughout her life, which lasts generally up to one year, and up to two years in captivity.

Predators

Natural predators include certain protozoa, spiders, and other insect species. Additionally, it is noted that cannibalism may occur within this species.

Ecosystem Role

As a decomposer, the lesser mealworm plays a role in recycling nutrients in the ecosystem by feeding on organic waste. However, it is also a significant pest in poultry farming and grain storage, affecting ecological interactions by outcompeting native species.

Economic Impact

This species can cause economic damage in the poultry industry by damaging housing structures and consuming feed, contributing to higher heating costs and weight gain issues in birds. Additionally, it has implications for food storage industries due to its pest behavior in stored products.

Health Concerns

The lesser mealworm can cause various health issues in humans due to the production of benzoquinone compounds that are irritating and potentially carcinogenic. Consumption by poultry can lead to intestinal obstructions and gut lesions.

Collecting Methods

• Hand collection from infested areas
• Use of traps to capture adult beetles
• Monitoring in poultry litter and storage facilities

Preservation Methods

• Preserving in alcohol or ethanol for scientific study
• Drying or freeze-drying specimens for display

Similar Taxa

• Tenebrio molitor (common mealworm)
• Alphitobius laevigatus (another species under the same genus)

Misconceptions

The larvae of the lesser mealworm are often confused with the larvae of other similar mealworm species, particularly due to the common use of the name 'buffalo worms' in marketing.

Tags

• lesser mealworm
• pest insect
• agricultural pest
• food source
• decomposer
• Alphitobius diaperinus