Controlling darkling beetle populations in poultry houses is important, because beetles destroy insulation, eat feed and carry disease. Robert Rowland, director of Ivesco technical services, has a masters of science degree in entomology and has over 15 years of experience designing and implementing insect and rodent control programs for poultry companies. Rowland spoke at USPOULTRY’s Production & Health Seminar. He said that beetle populations inside broiler houses are higher than before, and he explained why.

Built-up litter, with long intervals between house clean outs, gives beetles more habitat. The deeper the litter, the more beetles it can support. Darkling beetles are nocturnal, today’s low light levels, used for at least the last half of the growing cycle, means more active time for beetles, and more rapid population growth. Finally, years of using the same insecticides without rotating has selected for resistant populations of beetles. Rowland said that 75 percent of USA broiler complexes have beetles that are resistant to pyrethroids.

Robert Rowland, director of Ivesco technical services,
said that 75 percent of poultry complexes have
darkling beetles resistant to pyrethroids.

According to Rowland, there are only two classes of insecticide that are approved for use in poultry houses in Australia, and the industry there struggles to control darkling beetles, because of resistance to these two chemical classes that has built up over the years. In the USA, we are in somewhat a better position with four classes of chemicals approved for use; organophosphates, pyrethroids, spinosyns and boric acid. Sevin was widely used in poultry houses in the USA in the past, but it is no longer approved for this use.

In order to maintain the effectiveness of the insecticides that the U.S. poultry industry has access to, Rowland said that it is important to rotate the chemical used every two to three flocks. Broiler and turkey integrators follow similar rotations to maintain the effectiveness of coccidiostats, and wormers are rotated for all sorts of poultry and livestock for the same reason.


Rowland says to always follow the manufacturer’s instructions for mixing the insecticide, but he recommends making the most concentrated solution on the label. He recommends using the smallest amount of water that will do the job. It is important to adjust the ph of the water, he said that organophosphates and pyrethroids work best in acidic solutions, but spinosyns should have an alkaline solution. Rowland said that he can spray a 20,000 square foot house with six gallons of solution using his back pack sprayer. He said that it is best to use a spray nozzle that has a flat spray pattern and sprays a mist, not a stream. He recommends an 05 to 08 size nozzle. Rowland said that you should never mix insecticide with disinfectants.

When birds are in the house, the beetles will spend most of their time under the feed pans. If the beetle population is relatively high, beetles will be found along the walls of the house as well. Rowland recommends doing most of the spraying under the feeders and along the walls. He said that the best time to spray for beetles is within six hours of the birds being caught so that you can spray before taking litter out of the house. Rowland said that he is aware of at least four lawsuits involving beetles migrating from spread litter into the houses’ of neighbors. If you do in-house composting of litter between flocks, Rowland also recommends spraying the pile of litter after the windrow has been formed. Whether the windrow is sprayed prior to inhouse composting or if the litter is sprayed right after the birds leave the house, insecticide should be sprayed again within four days of the arrival of new chicks.

The number of beetles in the house can be checked to see if you are effectively controlling the population. Rowland checks for beetles when the flock is around two to three weeks old and again when it is four to five weeks old. He takes around six one-cup samples under the feeders and six one-cup samples along the walls. He dumps that samples from under the feeders together and uses a relative numerical scale to rate how many beetles are in the combined sample, and he does the same for the samples from along the wall. If the number of beetles increases from flock to flock, then he knows that his control methods need tweaking. The idea is to have fewer beetles, better feed conversion, healthier birds and less damage done to your poultry house.