Fatal attraction: Exploring the interaction between Aedes japonicus mosquitoes and the fly poison plant

Aedes japonicus is a mosquito species that has recently invaded Eastern North America and Europe. Despite its potential as a vector for pathogens such as West Nile and La Crosse viruses, this species remains understudied, and no control strategies have been developed to limit its populations. Since phytophagy significantly influences mosquito biology, including survival and reproductive success, we investigated the plants that Ae. japonicus feeds on in the wild. Notably, we observed this species landing on Amianthium muscitoxicum (fly poison), a toxic perennial commonly found throughout the Appalachian Mountains (USA). This observation led us to explore the following questions: 1) Does Ae. japonicus feed on fly poison? 2) Does the plant’s nectar affect mosquito survival? 3) Is Ae. japonicus a nectar thief or a pollinator of fly poison? 4) What olfactory cues emitted by the plant can Ae. japonicus detect and potentially be attracted to? Through laboratory and field assays, we found that Ae. japonicus uses fly poison as a carbohydrate source and can act as a pollen carrier, but the toxic properties of the nectar negatively impact their survival. We also determined that several volatile organic compounds emitted by the plant are detected by the mosquitoes and may mediate attraction. The consequences of feeding on a toxic plant on mosquito population dynamics and pathogen transmission will be discussed.