Investigating the effects of invasive grasses on Aedes aegypti behavior: Laboratory and field study findings

Invasive grasses may often displace native grasses, depleting their essential resources and reducing their diversity, richness, and abundance. As invasive grasses spread, insect vectors including mosquitoes may be impacted. Invasive grasses, such as Megathyrsus maximus thrive in moist and shaded habitats and can provide shade and resting sites that can be favorable for mosquitoes. This may influence the vector species abundance, distribution, and behavior, potentially elevating the risk of disease transmission. This study examines how native and invasive grasses may influence the behavior of Aedes aegypti, vector of yellow fever virus and other diseases. While a preliminary field study found no significant difference in Aedes aegypti oviposition site choice in response to native grass, invasive grass, or tap water infusions, these data may be unreliable due to a small sample size resulting from extreme temperatures and a reduced mosquito population. We repeated the field studies with a larger sample size and during the fall months which traditionally have peak mosquito activity in South Texas. Laboratory studies performed under controlled conditions to monitor flight behavior using a choice assay. Results will be discussed. The results from this study will provide valuable insights and contribute to understanding the impact of invasive grasses on mosquito populations. This information can help in effectively managing and mitigating the spread of both invasive grasses and the associated risks of disease transmission.