How to control darkling beetles in broiler houses

Assigning greater priority to pest management can lead to financial benefits for poultry growers.

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Darkling beetles are a constant issue in broiler barns and can cause serious financial and performance losses for growers if infestations go uncontrolled.
Darkling beetles are a constant issue in broiler barns and can cause serious financial and performance losses for growers if infestations go uncontrolled.
(Life on White | Bigstock.com)

Assigning greater priority to pest management can lead to tangible financial benefits for poultry growers. 

As part of the 2021 Midwest Poultry Federation Convention, Dr. Cassie Krejci, a technical field specialist with MGK Co., spoke about the economic impact of darkling beetles, a common poultry house pest, and how to combat and prevent infestations. 


Cassie KrejciCassie Krejci, MGK Co. (Courtesy Cassie Krejci)

 

The darkling beetle and its impact 

For poultry growers, darkling beetle infestations in litter are a frequent problem. 

Darkling beetles come from invasive species of insects that feed on grains and prefer to gather in places with high temperature and moisture. A poultry barn is an ideal habitat for the pests. Larva, also called mealworms, gather under feed and waterlines. Pupa burrow into housing insulation and other hard surfaces. As adults, these beetles are active and can fly as far as a mile. 

In a poultry barn, Krejci said, a single pair of beetles can turn into a population of more than 5 million in as little as four months if uncontrolled.  

Beetles consume feed, create a biosecurity risk by spreading disease, destroy houses by boring into the house's walls, harm feed conversion rates and disturb the chickens in the house. In total, Krejci said the beetle causes significant economic losses for growers due to these destructive behaviors. She estimated every $1 spent on controlling beetles prevents $9 in losses. 

Best practices for beetle management 

Krejci advocated for using an integrated pest management control strategy containing four different planks: insecticides, physical controls, sanitation and cultural control. This plan creates a well-balanced approach that doesn’t rely on a single factor for success. 

Cultural control is manipulating the environment to keep an insect population from growing or flourishing. In broiler production, this is done by windrowing litter. The heating effect inside the windrows drives out mature insects and kills the population still inside the windrow. Putting insecticide on top of the litter can catch beetles escaping from the windrow. 

Physical control is physically removing or keeping insects from a certain area. Cleaning out the litter or caking out the litter as often as possible directly removes as many eggs, larvae, pupae and adults as possible. 

Sanitation is keeping the house clean. This means clearing out the mortalities, cleaning up spilled litter, and repairing active water leaks.

White Chickens In Poultry House 8Broiler houses make ideal habitats for darkling beetles, but the pest can be controlled economically through sanitation and insecticide use. (ugurerden | iStock.com)

 

Insecticides

Chemical insecticides form the final plank of the integrated pest management control strategy. Krejci said these substances are classified by their mode of action, or how they kill insects. Most insecticides used in beetle control act on the nervous system. Some are designed to target adults while others target juveniles. 

There are six classes of insecticides available. Four focus on adults and two on juveniles. Growers should focus on the active ingredients used in different insecticides and rotate chemicals to avoid creating insecticide resistance. 

Insect growth regulators, or IGRs, focus on the juveniles by preventing them from growing into adults and killing them. Krejci identified pyriproxyfen and novaluron as two of the more common IGR active ingredients used in the poultry industry. These are long-term chemicals which are good supplements to adulticide application. Using IGRs is also beneficial because it keeps the bugs from breeding and makes them easier to kill with adulticides. 

Resistance is a notable problem for litter beetle control because there are limited classes of insecticides available for beetle control. Resistance is the genetic ability of an organism to withstand a toxin. This is a trait that can be passed on to subsequent generations.

Switching products every two to three applications limits development of resistance. Insecticides are also applied to the entire floor of the house, rather than in bands, as a means of preventing resistance. Piperonyl butoxide, or PBO, is also used as a supplement to boost efficacy of insecticides. 

Insecticide application

Contact insecticides and an IGR should be applied to as much of the litter as possible before the birds arrive. About one gallon should be used for every 1,000 square feet, she said, and insecticides should be applied at the highest label rate possible to prevent resistance.

Insecticide should be regularly applied outside the house, too. This creates a preventive barrier, blocking beetles from wandering in. 

A program example

Krejci provided framework for a comprehensive beetle management program.

Before bird placement:

  1. Cleanout and windrow.
  2. Apply long-term insecticide to the floor.
  3. Add fresh litter.
  4. Surface spray on top of the litter two to three days before placement. Apply at the highest rate possible and apply about 1 gallon per every 1,000 square feet of treated area. 
  5. Spray the exterior areas including, foundations and walls and any areas around openings twice per year. 

While birds are in the house, growers can still act to control beetles. Krejci said it is possible to spray insecticide on stacked litter and windrows, apply it to exteriors and potentially fog or spray litter for increased control mid-flock.

Krejci placed the average cost of a pre-treatment beetle control program at approximately $125 per house per growout cycle. It is a worthwhile investment, she said, because doing nothing to control beetles will cost the grower far more over time. 

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