written by: Amanda Rae Brucchieri
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​Back in the UMD Entomology Department where she previously earned her Master’s degree, Dr. Morgan Thompson is now a Postdoctoral Research Associate in the Burghardt Lab. Upon returning to the department, she shared some interesting findings from her doctoral research. At this week’s Colloquium, Dr. Thompson told three stories: undercover operation, eavesdropping plants, and phytochemical diversity. Altogether, these research tales earned her the prestigious title of PhD from Texas A&M University. 

written by: Jillian Stewart

What do you do with a drunken crayfish? If you’re in the Herberholz lab, you quantify how long it takes for the crayfish to get well and truly sloshed, and use it to model the impacts of social isolation on the nervous system.
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Crayfish are a valuable model for the nervous system, with which researchers are quite familiar. Their relatively large neurons are easy to work with and can survive outside the animal for several hours. The crayfish nervous system has been well mapped and the roles of individual nerves are often known (Venuti et al, 2021).

In addition to their nervous systems, crayfish exhibit simple social behaviours. Crayfish form linear social hierarchies by dueling with each other. These hierarchies last for about seven days, after which the crayfish forget who won and duke it out again. Dr. Herberholz and his lab at UMD’s Department of Psychology used these social systems to model how isolation affects the nervous system’s response to alcohol. They placed individual crayfish, some socially isolated for seven days and others communally housed, in a tank of water with alcohol in it.

Crayfish exhibit distinct phases of intoxication: for the first ten or fifteen minutes, they are unaffected. Then, they start to stand up tall on their tip-toes. Next, they perform an escape maneuver by flipping their tail repeatedly (image 1). Finally, the crayfish lands on its back and is unable to right itself. At this point, the crayfish is returned to fresh water and recovers in a couple hours. 

written by: M. Rho Ma

​Insects are both essential to ecosystems and a source of challenges for human health and agriculture. They pollinate crops, serve as food for other species, and contribute to nutrient cycling, but they can also act as vectors for diseases or suffer population declines due to human activity. Striking a balance between conserving beneficial insects and managing harmful ones is a pressing concern in entomology. The following research-in-progress talks by graduate students demonstrate how entomological research bridges the gap between ecological understanding and practical solutions, focusing on pesticide impacts, mosquito adaptation, and disease surveillance.  

written by: Michael Adu-Brew and Leo M Kerner
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​The United States Environmental Protection Agency (EPA) was instituted in 1970 and is tasked with matters of environmental protection. Its mandate is to provide clean air, land, and water, reduce environmental risk based on science, administer and enforce federal laws protecting human health and the environment, and promote environmental stewardship1 . As part of the UMD Department of Entomology seminar series, Mr. Keith Sappington – a Senior Science Advisor at EPA’s Office of Pesticide Programs – provided an overview on December 6 th , 2024 of the agency’s procedures for pesticide ecological risk assessment and how these procedures are used to assess risk to insect pollinators and endangered species.

The Hamby Lab works to encourage the use of Insect Pest Management (IPM) in agroecosystems, aiming to improve management tactics and create more sustainable alternatives. Their latest study, “Preventative insecticides reduce seedling injury, but do not increase yield in Bt and non-Bt corn grown in the mid-Atlantic” demonstrates that while preventive tactics, like neonicotinoid seed treatments and in-furrow pyrethroids, effectively manage pests, consistent pest pressure is needed to justify their use. 
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After evaluating the effectiveness of these preventative insecticide treatments in field corn production, their study finds that while damage can be reduced using these early season preventive measures, at the end of the season yield is not significantly increased. The take-home message from the study: These preventive measures do not pay off in all situations and insecticide use could be reduced. A more effective IPM approach incorporates pest pressure, using preventative insecticides where pests consistently occur and foliar insecticides for sporadic issues that spring up. Multiple non-chemical prevention strategies should also be used before resorting to chemical treatments.