Invasive Aedes

Invasive Aedes Mosquitos in Fresno County

The invasive mosquito Aedes aegypti is distinct from many of our regular species in its aggressive daytime biting, tendency to enter and remain in homes, and capability of transmitting a number of imported tropical diseases. Aedes aegypti is known as the “yellow fever mosquito” and has been detected in Fresno County in a variety of areas since first appearing in 2013 in the cities of Madera and Clovis.

How to Identify an Invasive Aedes aegypti Mosquito

Aedes aegypti is a small, black and white mosquito. It may be active around dusk and dawn, but bites most often during the day and typically occur indoors. This aggressive type of mosquito is capable of transmitting a variety of imported diseases including the Zika virus.


Aedes aegypti is capable of transmitting a number of pathogens, including yellow fever virus, Zika virus, dengue virus, and chikungunya virus.  While none of these pathogens are regularly found in the United States, there is a risk that a traveler could return from abroad with an active infection and introduce the pathogen into the local aegypti population.  Illnesses associated with the Aedes aegypti have not been reported in Fresno County.