Lesser Mealworm Beetles in Poultry and Game Bird Facilities'

While they can be found in several types of poultry production systems, these insects are most troublesome in turkey, broiler, and pullet houses where deep litter and open-floor housing provide an ideal habitat for the beetles to survive and reproduce.

 

 

 

These beetles have a high reproductive rate, are vectors of pathogens that cause disease in poultry, and can significantly damage building structures. They can also be difficult to control, may migrate from litter disposal sites to urban housing where they are a nuisance, and when numerous may consume poultry feed.

 

Litter beetles can carry pathogens that cause disease in poultry, including fowl pox, E. coli, Salmonella spp., Marek’s disease, botulism, coccidiosis, New Castle disease, avian leukosis virus, and infectious bursal disease virus. Beetles may also be intermediate hosts of Choanotaenia infundibulum (chicken tapeworms) and cecal worms. Consumption of large numbers of beetles may have adverse health effects on birds, especially young birds.

 

In addition to potential pathogen transmission, litter beetles cause extensive damage to building insulation in poultry houses. This occurs when larvae bore into the insulate to pupate while avoiding subsequent predation by adult beetles and vertebrate predators like mice.

 

 

 

Like other poultry pests, such as flies, litter beetles are also known to invade neighboring homes, especially if litter is removed from heavily infested houses. Lawsuits against poultry operations relating to litter beetle infestations have been filed in response. Care must be taken to properly control these pests to protect not only the birds but also the environment and neighboring areas.

 

 

Beetles have four life stages: egg, larvae, pupae, and adult. The life cycle from egg to adult is dependent on environmental conditions (such as humidity and temperature) and farm conditions (such as food and water availability) but generally ranges from 35 to 90 days.

 

 

 

Larvae are yellowish brown and resemble centipedes or wireworms. Larvae can be found clustering together under manure or litter, feed sacks, or feed storage areas. Pupae are ¼ inch long and an off-white to light-brown color as they age. While larvae and adults are generally found together, pupae are in lower, compressed litter, dry manure, soil, or insulation. Adults are ¼ inch in length, elongate, and a shiny black or brown depending on age. Adults may be found with larvae or actively crawling on walls, edges of doors or windows, or beams. A female beetle has the potential to lay more than 2,000 eggs in the manure and litter, especially under feed and water lines. Adults can live more than three to 12 months and will continue to produce eggs throughout most of their lifetime at one-to five-day intervals.

 

 

 

Litter beetles are not found in equal numbers throughout the poultry house. Instead, they tend to clump together in areas that are favorable—in general, areas that are protected and have adequate moisture (damp but not very wet) and food and looser and deeper litter such as under feeders. If objects are not available, beetles may be found around the edges of caked litter.

 

 

Litter beetles will often be found in groups under protected areas in the poultry house. Under feeders is a common place to locate them. 

 

 

Litter beetle populations should be monitored to evaluate when to control and to provide feedback on how well implemented control practices are working.

 

 

Visual inspection can begin when birds are placed in the house until they are removed. Beetle numbers can be counted by digging 2 to 3 inches into the litter; under feeders, cracks, and crevices; around equipment; in insulation; and under dead birds.

 

 

Cup sampling is an alternative method of monitoring. In this case, six one-cup samples from under feeders and six one-cup samples from by walls are taken. Sampling should occur when flocks have been in buildings for two to three weeks and again between three and five weeks. If greater accuracy is needed, samples can be taken more frequently (weekly or biweekly). Beetles from these samples should be counted and recorded, and if numbers significantly increase between the first and second samples or consistently over time with more frequent sampling, control should be considered.

 

 

Traps can be used to monitor litter beetles. These are made of 2-inch-diameter PVC pipe. Each trap should be 10 to 12 inches long with a roll of 8-by-11-inch corrugated cardboard inside. Traps should be staked down to prevent birds from moving them. At least three traps should be evenly distributed throughout the house, avoiding wall edges or other areas of densely packed litter. As with hand counting and the cup method, ideally, the traps should be removed or replaced, and beetles counted weekly or biweekly. If beetle and larvae counts cannot be made at the time that the traps are collected, the cardboard can be placed in a plastic bag and examined later.

 

 

Litter beetle traps can be used to monitor beetle numbers. The key is to be consistent and record numbers over time.

 

 

An integrated pest management (IPM) plan should be used for effective litter beetle control. IPM control plans can be developed after identifying and understanding the pest life cycle and establishing a monitoring plan. Control plans include a combination of cultural (prevention), mechanical or physical, biological, and chemical methods to improve control based on the pest’s life cycle and reduce harm to animals, people, and the environment.