AUBURN, Ala. — Whenever Dylan Brown flies out of Atlanta to visit his family in California, he likes looking out the window, especially at the poultry houses that dot the Southeastern region of the country.
“I’m thinking that each poultry house I fly over most likely has poultry litter beetles, since I haven’t met a poultry producer yet who doesn’t have the pest,” said Brown, who is a post-doctoral student in the Auburn University College of Agriculture’s Department of Entomology and Plant Pathology.
Brown’s interest in the poultry litter beetle recently earned him a $5,000 grant from the Alabama Agricultural Experiment Station for a project titled “Combating Insecticide Resistance in Poultry Litter Beetles: Toward Sustainable, Scienced-Based IPM Solutions.”
This marks the first year that graduate and post-doctoral students have been eligible for the AAES internal grants program.
“It definitely felt great to get some funding for a project I really care about and that can make a real impact on poultry farmers in the Southeast,” Brown said. “It’s also a nice confidence booster when a panel of experts believes your project is worth supporting financially. If I continue in academia, the grant writing process itself was highly beneficial. It’s great that the college decided to provide this opportunity for graduate students to get funding for their own projects.”
Brown is originally from Riverside, Calif., and said he rarely went anywhere outside the state before coming to Auburn.
“Although I didn’t come from a traditional agricultural background, I have always been enamored by agriculture, which motivated me to go to the University of California, Riverside, for my undergrad and eventually master’s as well,” he said.
He was able to join an entomology lab throughout his undergrad that developed strategies to combat a devastating grape pest (the glassy-winged sharpshooter) throughout the wine counties in California.
After working with insecticide resistance during his undergrad and master’s, Brown wanted to gain a deeper understanding into the molecular genetics behind the development of insecticide resistance.
Pesticide resistance in all pests, including insects, is one of the biggest challenges farmers and healthcare experts are facing, he said.
“I really wanted to see if I could find an ‘Achilles’ Heel’ at the molecular level to reduce resistance development while still controlling pest populations,” Brown said. “As it turned out, Dr. Nannan Liu was one of the world’s leading experts in the molecular genetics behind insecticide resistance in important insect pests, which is what brought me to Auburn University.”
About two to three years into his Ph.D., he said. Liu became the interim head of the Department of Poultry at Auburn.
“During that time, multiple faculty members informed her about how disruptive poultry litter beetles can be to the poultry industry due to their ability to transmit many deadly pathogens to the birds, and the structural damage they can have on poultry houses,” Brown said.
“We reached out to more poultry experts and farmers who told us that poultry litter beetles can get out of control and that some of the insecticides they were using didn’t seem to be having much effect. When I dug a little deeper, I found that very little work had been done on the resistance status of this beetle, and I believed a project investigating this could really help farmers in the region.”
Poultry beetles can eat just about anything that is remotely edible, including chicken feed, manure, broken eggs, other insects and chicken carcasses, Brown said. Since they eat and develop in poultry house filth, they can pick up pathogens like E. coli, salmonella, avian flu and any other harmful pathogens within the poultry house.
Unfortunately, the birds’ instincts are to eat the moving insects rather than their stationary chicken feed. which can lead to the mechanical transmission of pathogens throughout poultry houses. The larvae also like to pupate in undisturbed locations so they will migrate to the walls of houses and burrow into insulation which can lead to higher energy costs for producers.
“The poultry beetle can be an elusive pest that likes to spend most of its time under poultry litter or in cracks and crevices,” Brown said. “Poultry producers can remove all the litter in a consistent manner to reduce beetle populations, but this can be costly and time intensive.
“The common control technique is to apply insecticides in-between flocks, but due to the beetle’s cryptic nature, it is hard to ensure the insecticide contacts the beetles. Another emerging problem is the development of insecticide resistance. which was largely unknown throughout the Southeast. The beetle’s cryptic nature and the development of insecticide resistance could make some insecticides useless against these beetle populations.”
While there was some research out of New York, Texas and Arkansas several years ago suggesting the development of insecticide resistance by poultry litter beetles to some chemicals, not much research has been done since then on the topic, Brown said.
“There seem to be fewer insect toxicologists throughout the U.S. and those who are here have yet to really research this important pest,” he said. “Farmers were using multiple classes of insecticides with some anecdotal evidence that some worked while others didn’t, but a full comprehensive look at it had never been completed until now.”
Brown’s research project was created to address the fundamental issue of which insecticides are no longer effective in controlling poultry litter beetles. Understanding which insecticides these beetles have developed resistance towards can help farmers change to more effective insecticides and stop using the less effective ones.
“Insecticides aren’t cheap, so if we can help farmers avoid spraying insecticides that no longer work and change them out for insecticides that do work, then we can both save farmers money and control the beetle populations.”
Brown and Liu are working now to publish their findings in science journals and create Extension publications that can be used by producers to know which insecticides work and which ones don’t.
“We are also in contact with farmers who let us collect some of their beetles to test, and we’ve let them know which insecticides are still effective,” Brown said. “Our research suggests that these beetles are resistant to most of the insecticides that we tested that are approved for use in poultry houses, so there still is a lot more work that needs to be done to ensure we can effectively control this pest. However, I believe this project has established a solid foundation for future research.”
Liu, now an endowed professor with the Auburn University Department of Entomology and Plant Pathology, said the research being conducted by her and Brown is especially timely because insecticide resistance in the poultry litter beetle is becoming an increasingly serious challenge for the poultry industry across the Southeastern United States.
“As producers continue to rely on chemical control, resistance has reduced the effectiveness of many commonly used insecticides, leading to higher production costs, pest outbreaks and increased risks to poultry health and biosecurity,” she said. “Despite the economic importance of this pest, there is still limited information on the extent of resistance and the molecular mechanisms underlying it.”
By identifying resistance patterns and mechanisms, Liu said this project will provide critical information needed to develop sustainable, science-based integrated pest management strategies and resistance-monitoring tools that can benefit poultry producers throughout the region.
“As Dylan’s mentor and co-PI, my primary role is to provide scientific guidance, technical training, and professional development throughout the project,” Liu said. “I have worked closely with him on experimental design, data analysis, interpretation of results, and dissemination of findings through publications and presentations.
“Drawing on my experience in insect toxicology, insecticide resistance, and integrated pest management, I have helped ensure that the research is conducted rigorously and that project objectives are achieved on schedule. Equally important, I view this project as an opportunity to help Dylan develop into an independent scientist by strengthening his research, communication, and leadership skills while preparing him for a successful career in agricultural and pest management research.”
