Steps in Controlling Darkling Beetles

— Written By James Parsons and last updated by

First reported as a pest in deep litter houses in the early 1950’s, the darkling beetle, Alphitobius diaperinus, has become a major pest in poultry houses.  Also called litter beetles, lesser mealworms or “black bugs”, these insects are most troublesome in turkey and broiler houses where deep litter and open floor housing provide an ideal habitat for the beetles to survive and reproduce.

 Each poultry company has its own program for controlling darkling beetles and use a variety of products.  Robert Rowland, Ken Macklin, Gene Simpson, Jim Donald and Jess Campbell, in a past issue of Poultry Times, presented the following keys to successful beetle control. 

Rotate between the different classes of chemicals at least every two flocks.  If one product is used for an extended period of time, resistance to it will build in the beetle population and that chemical will no longer be effective.

Do not be too hasty in judging any particular chemical to be ineffective.  The number of beetles killed in the first 24 hours is not the best indication of effectiveness.  Some insecticides will kill the beetles in just a few hours; others may take a few days to begin killing the beetles and continue killing the beetles for the entire growout.  When the birds are 4-5 weeks old, look under several feed pans and see how many beetle adults and larvae you find.  If you only find a few beetles and larvae, you have good control.

Apply the label recommended amount of each pesticide.  Using less than the recommended amount will lead to increased resistance to the insecticide.

If you are seeing large populations of beetles, apply your insecticide before placement of each flock.  This will keep the beetle population under control in every flock.

Apply insecticide using as little water as possible.  It is best not to exceed 12 gallons of water in a 500-foot long house.  Change your nozzle tips to a flat fan, 04-08 nozzle tip to get a fine mist, instead of a course spray application.

Apply insecticide in a 3-foot wide band under the feed lines and a 3-foot wide band along the walls, including the footing, and 2 feet up onto the wood above the footing, instead of the entire house.  Focusing the insecticide applications in areas where the beetles are living will offer much better control.

Add one packet of citric acid or PWT to each Organophosphate or Pyrethroid insecticide tank mix before applying the material.  These insecticides kill more beetles when they have an acid added to the tank mix.

Apply insecticide on top of the litter after caking out, or on top of fresh shavings after clean out. The beetles crawl on top of the litter as they are making their way to the feed line areas after bird placement.  If you apply the insecticide to the bare floor, the results will not be as good.

After caking or clean out, apply insecticide to any litter stored in the litter storage shed.  This will help prevent the beetles from migrating right back into your houses.