McGregor Vector Ecology Lab

More about the McGregor Vector Ecology Lab

One of the primary goals of the Arthropod-Borne Animal Diseases Research Unit is to protect United States livestock from endemic vector-borne diseases. We currently have three important vector-borne viruses of livestock that we study, which include bluetongue virus, epizootic hemorrhagic disease virus, and vesicular stomatitis virus. Outbreaks of these pathogens can result in morbidity and mortality to livestock and significant economic impacts for ranchers and livestock producers. In the McGregor lab, we aim to protect livestock from these diseases by better understanding the vector insects that spread them, Culicoides biting midges. We have several ongoing ecological research projects to better understand the interactions of these biting midges with their environment and hosts. You can read about a few of those projects below. Ultimately, we hope to use this information to improve our ability to collect, monitor, and control these vectors.

If you’re interested in learning more about the work going on in the McGregor lab or potentially joining us, please email the head of the lab, Bethany McGregor, at Bethany.McGregor@usda.gov

 

Phenological patterns of Culicoides populations in the Great Plains

 

Photos taken by Bethany McGregor at a field site on the Konza Prairie Biological Station showing seasonal changes in a larval habitat.

In order to control a group of vector insects, it’s important to understand both where and when they are on the landscape. In order to get at the “when”, we are studying the phenology, or seasonality, of midge populations on sites associated with diverse larval habitats and host populations. We are looking at the abundance patterns of both larval and adult midges throughout the year to better understand community dynamics and improve our ability to predict when vector-borne disease outbreaks may be more likely.

 

Culicoides host associations 

Photo taken by Bethany McGregor at the Konza Prairie Biological Station where managed bison and cattle herds present a unique opportunity to study Culicoides host associations.

Female biting midges require blood in order to develop eggs and this blood feeding behavior is what can lead to the transmission of diseases. Understanding which midge species are feeding on animals that are susceptible to vector-borne diseases can give us valuable information on which species may be contributing to the spread of diseases and may help us to better target control strategies towards those species. We are studying host associations using several tools including blood meal analysis to find out specifically which host animals midges are feeding on in the field using the blood they’ve ingested and also game camera studies to better understand host use of environments where midges are produced.

 

Characterization of Culicoides larval habitats

Photo taken by Bethany McGregor of water filled hoofprints, which are a unique habitat that can support development of some Culicoides species.

Culicoides larvae develop in semi-aquatic habitats, often at the soil-water interface of places like organically enriched ponds, streams, and springs. Unfortunately, specifics on the larval habitats associated with many Culicoides species are still poorly understood. We have ongoing projects characterizing the midge communities associated with different habitat types, management styles, water and soil chemistry metrics, and microbial communities. If we can better understand where midges develop, we can better predict which habitats may produce significant midge populations which could help us to better target vector control strategies.