The Lesser Mealworm Beetle is the most damaging pest to the poultry industry. It is the most common beetle found in broiler litter. These insects are a vector for a variety of poultry diseases, including Marek’s disease, are intermediate hosts for parasites, can transmit bacterial diseases such as Salmonella spp., and the larvae can cause significant and costly damage to poultry housing. There can also be human health risks associated with close contact and exposure to these beetles.
Poultry have difficulty digesting the beetle and larva. If eaten they are put at risk of ingesting harmful organisms, run the risk of intestinal obstruction and gut lesions and it will detrimentally affect their food conversion rate. Chicks are more likely to be infected by eating the larvae and it can lead to death in younger, weakly chicks.
The Lesser Mealworm is reddish brown is colour with a wide oval shape and is roughly 6 millimetres in length. The beetle is mainly nocturnal and thrives in warm, humid environments thus poultry litter is the ideal habitat for them. They feed on the litter as well as mould and feathers. They can also infest and consume dying birds, especially chicks. The female, which can have a two year life span, can produce up to 2000 eggs in a year and within as little as one week these larvae emerge. The larvae are quite active and mobile and can mature in approximately 40 days in the right environment.
Regular removal of manure and litter from poultry houses will help to control the beetle. Care should be taken with disposal of litter to prevent further spread of the infestation. It can be difficult to monitor and assess the extent of the infestation as adult and larvae make themselves inaccessible by burrowing and also by being nocturnal. Care should be taken to ensure that any infested food is not taken into housing. Physical barriers such as metal proofing structures can restrict the migrating of larva to pupation sites within the fabric of the building or using larvae resistant insulation material. Before repopulating houses cooling to sub-zero temperatures for a number of days will help control residual populations. There are a number of insecticides which can be used in the control of the Lesser Mealworm. It is advisable to consult your veterinary consultant on these products and work out a management system that works best for your situation.