Aaron Ashbrook

Assistant Professor Louisiana State University

  • Baton Rouge LA

Dr. Ashbrook's research focus primarily on cockroach and bed bug management.

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Louisiana State University

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Biography

Dr. Ashbrook’s research focuses on urban and peri-urban pest insects, with an emphasis on bed bugs, cockroaches, termites, biology, behavior, and other structural pest issues in Gulf Coast environments. He uses field surveillance, laboratory bioassays, and recent studies to craft sustainable integrated pest-management strategies that protect homes and urban landscapes.

Areas of Expertise

Urban Pest Management
Pest Control
Biocontrol
Insect Biology
Insecticide Resistance
Insect Physiology
Insect Behavior

Research Focus

Urban Pest Insects & Integrated Pest Management

Dr. Ashbrook’s research focuses on urban and peri-urban pest insects, with an emphasis on subterranean termite biology, behavior, and insecticide resistance in Gulf Coast environments. He uses field surveillance, laboratory toxicology assays, and integrated pest-management modeling to craft sustainable control strategies that protect homes and urban landscapes.

Education

Purdue University

Ph.D.

Entomology

2020

Purdue University

M.S.

Entomology

2015

Grand Valley State University

B.S.

Biology

2011

Spotlight

3 min

The Asian Needle Ant (Brachyponera chinensis) Found in Southern Louisiana

In Louisiana, there are several ant species that are capable of stinging besides the red imported fire ant (Solenopsis invicta), such as the elongate twig ant (Pseudomyrmex gracilis), Comanche harvester ant (Pogonomyrmex comanche) and several species in the subfamily Ponerinae. The Asian needle ant (ANA) (Brachyponera chinensis) joins the list and has been confirmed in the state. Recent reports on the Asian needle ant by Mississippi State University extension entomologist, Santos J. Portugal and other urban entomologists in the region spurred the authors at Louisiana State University to investigate the presence of ANA in their state. By happenstance, two citizen scientists had reported sightings of the ant on iNaturalist at two Louisiana parks in August 2024 and June 2025. Therefore, on June 17, 2025, an LSU entomologist visited one of the parks to ground-truth the citing by collecting the ant, as he had prior experience with it. The Asian needle ant is a termite specialist, preferentially feeding on them, often living in close proximity with termite colonies and inside damp wood. To collect the ants, water-soaked wood was located in a forested area, broken open, revealing ANA, and they did not react aggressively to the disturbance. The ants immediately grabbed immature larva and retreated into crevices, not bothering the collectors at all. Upon retrieval, an LSU entomologist used a microscope at 40x to 60x magnification and the dichotomous key authored by MacGown (2003) to confirm that the collected specimens were ANA. It is important to verify the identity of invasive species submitted on citizen scientist projects as the images may not be of sufficient quality to get a positive identification. The ANA was discovered in the U.S. in 1934 while individuals were researching Argentine ants (Linepithema humile). Since the introduction of the ANA, it has spread to many states within the U.S., ranging from Wisconsin to Texas to the east coast. ANAs are medium sized (about 5 mm long) and slender. The species originated from Asia. Queens are slightly larger (6.5 mm) and look similar in appearance to workers. ANAs are black to dark brown in coloration, with light brown legs, mandibles and antennae. To distinguish the ant from other look-alikes, ANA has a large single petiole node that extends above the thorax or alitrunk, and a shiny mesopluron on the side of the thorax. ANA colonies are typically small in numbers, up to a few thousand individuals in large colonies. They are polygynous, meaning they have multiple queens. ANAs use a unique foraging behavior, where the worker carries another worker to a food resource, then drops off the worker to assist in food transport. ANAs do not form mounds, but instead nest in damp, high humidity areas, such as rotting logs, void spaces, under rocks and in leaf litter. They are typically found in forested areas. They also form multiple colonies within an area, which is called polydomy. ANAs swarm during the spring and early summer, although this time range may vary for Louisiana. People typically encounter the ants when they are working with wet wood or digging in moist soil. This is when someone may potentially be stung, although they are not aggressive. The sting is reported similar to that of a honeybee. Individuals who are allergic to stings may have a life-threatening anaphylactic response if stung by the ant, which requires medical attention. Wearing gloves is adequate protection from ANA stings while working with rotten wood or soil in infested areas. People who are sensitive to other insect stings should be aware of the potential for ANA stings and carry an approved rescue device for severe allergenic responses. In addition to feeding on termites, the Asian needle ant will feed upon beetles, craneflies, springtails and native ants found in their preferred habitats. Because of their ability to prey upon native ants, they can impact native species that deposit seeds in the soil, thus reducing floral diversity. Therefore, ANA is capable of reducing both native animal and plant diversity in infested areas. Article originally posted here.

Aaron Ashbrook

2 min

Springtime swarms: What you need to know about termite alates

As temperatures warm up across Louisiana, so does termite activity. Homeowners may soon begin to notice large swarms of winged insects in and around their homes. These are termite alates, also known as swarming termites. “Swarming is how termites establish new colonies,” said LSU AgCenter entomologist Aaron Ashbrook. “Seeing swarms around your home doesn’t necessarily mean you have an infestation, but it does mean termites are nearby.” Alates are the reproductive members of a future termite colony if they can successfully establish. Each spring, usually following a warm rain, these termites leave their established colonies to find new places to nest. Many alates are produced because a low percentage of them are able to establish a colony. After swarming, they shed their wings and pair off to begin new colonies, which is how they end up in homes. Louisiana’s warm, humid climate makes it an ideal environment for termites, especially the Formosan subterranean termite, one of the most destructive species in the United States. Termites can silently cause thousands of dollars in damage before homeowners know they’re there. Tips for homeowners: Don’t panic, but don’t ignore it. Seeing swarms outside is common, but if they're inside your home, call a licensed pest control professional. Look for signs. Discarded wings, mud tubes, water stains, moisture buildup, and soft or hollow-sounding wood can all indicate a problem. Reduce moisture. Termites thrive in damp environments and require moist wood to attack structures. Fix leaks and ensure proper drainage around your home. Schedule regular inspections. Annual termite inspections are recommended, especially in high-risk areas like Louisiana. “Termites can cause extensive structural damage to your home that may go unnoticed,” said Carol Friedland, director of LaHouse Research and Education Center. “Early detection and prevention can save homeowners a lot of stress and money.” The LSU AgCenter’s Department of Entomology and LaHouse Research and Education Center provide research-based guidance to help Louisiana residents protect their homes from termites and other structural pests. Learn more by searching for “termites” at www.LSUAgCenter.com. Article by Shelly Kleinpeter, originally posted here.

Aaron AshbrookCarol Friedland

Media Appearances

Here's how to protect the Baton Rouge bat population, plus how they benefit Louisiana yards.

The Advocate  online

2025-06-07

Aaron Ashbrook, an assistant professor for the LSU Entomology department, specializes in urban entomology. He recently hosted a seminar series at LSU AgCenter's LaHouse Research and Education Center for state sanitarians who expressed interest in the local bat population. Ashbrook's lecture focused on correcting misinformation about pollinator support, mosquito management and bat conservation.

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Termites aren’t just a threat to structures

The Eunice News  online

2025-05-30

“If we fill our raised garden beds with logs or large pieces of wood in addition to compost that has a high percentage of wood inside, we can inadvertently lure in termites,” said Aaron Ashbrook, an entomologist with the LSU AgCenter.

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Does your home have roaches? Here’s how to spot, kill and get rid of this common Louisiana pest

MSN  online

2024-08-09

There are many cockroach species, not just in the state but worldwide. According to LSU Assistant Professor of Urban/Pieri-Urban Entomology Dr. Aaron Ashbrook, the most common two species are the American cockroach and the German cockroach.

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Articles

Lethal disruption of the bacterial gut community in Eastern subterranean termite caused by boric acid

Journal of Economic Entomology

2024

The Eastern subterranean termite, Reticulitermes flavipes (Kollar) (Blattodea: Rhinotermitidae), is a significant pest, causing extensive damage to structures that amount to substantial economic losses. Boric acid is widely used for wood preservation due to its stability and broad-spectrum insecticidal properties, yet its impact on termite gut microbiomes and the implications of such effects remain understudied. Our study evaluates the dose-dependent mortality of R. flavipes upon being provided boric acid treated filter papers and investigates the resulting dysbiosis within the termite gut microbiome.

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Lethal and sublethal heat-exposure of bed bugs (Cimex lectularius L.) causes alarm pheromone emission and elicits a movement response in nearby recipients

Scientific Reports

2024

Many gregarious insect species use aggregation and alarm pheromones. The bed bug, Cimex lectularius L., emits an alarm pheromone (AP), a 70/30 blend of (E)-2-hexenal and (E)-2-octenal, when threatened. Bed bugs avoid temperatures above 43 °C, which are lethal to bugs and used commercially as spatial heat treatments to manage infestations. However, the interaction of bed bug AP in heat avoidance has not been investigated. The goal of this research was to: 1) determine if bed bugs emit AP as an alarm response to heat exposure, and 2) quantify the behavioral responses of conspecifics to AP emitted by heat-exposed bed bugs.

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Comparative Efficacy of a Fungal Entomopathogen with a Broad Host Range against Two Human‐Associated Pests

Insects

2022

Bed bugs and German cockroaches have adapted to thrive in human structures. In the present study, we use different techniques to expose bed bugs and German cockroaches to Beauveria bassiana, a fungal pathogen that only infects insects, to test their susceptibility to infection. The tests with bed bugs revealed that they were highly susceptible to fungal infections, no matter how we exposed them to the pathogen. The German cockroaches were only infected by fungi through certain routes of exposure. Fungal pathogens have the potential to control bed bugs but will require additional research and innovative technologies to be effective against cockroaches.

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