Adult mosquito abundance began to rise in April, which is typical in the spring, but overall numbers remain low. Aedes sierrensis, a mosquito that breeds in treeholes, was first detected this year as an adult during April. It will continue to be present until autumn. Culex erythrothorax has not yet been collected in traps in 2023, although on average it is the most abundant mosquito in April. This…

The District conducts intensive surveillance for invasive Aedes mosquitoes during the summer months. The surveillance program mainly targets two container-breeding species, Aedes aegypti and Aedes albopictus, which have been increasing their range within California over the last several years. The presence of these mosquitoes is highly undesirable because they are aggressive human biters and also…