Arizona is not typically thought of as mosquito country — but monsoon season changes everything. From July through September, the dramatic increase in standing water from summer storms creates ideal breeding conditions for several mosquito species. The most common in Arizona include Aedes aegypti (the yellow fever mosquito, which also transmits dengue and Zika), Culex quinquefasciatus (the southern house mosquito, which can carry West Nile virus), and Aedes albopictus (the Asian tiger mosquito). Mosquito activity in Arizona is strongly tied to temperature and standing water — they cannot breed without it, and they become inactive when temperatures drop below 50 degrees Fahrenheit.

Mosquitoes are most active at dawn and dusk, when temperatures are cooler and winds are calm. The Aedes species (yellow fever and Asian tiger mosquitoes) are unusual in that they are also active during the day, especially in shaded areas. Activity peaks in July, August, and September during monsoon season, then drops sharply in October as temperatures cool. In the Phoenix metro area, Pinal County Vector Control monitors mosquito populations and issues advisories when West Nile virus activity is detected. The best time to be outdoors without mosquito protection is midday in summer (when heat suppresses activity) and any time in winter.

The most effective mosquito control starts in your own yard. Eliminate all standing water — empty flower pot saucers, bird baths, clogged gutters, and any container that holds water for more than a few days. Treat ornamental ponds and water features with Bacillus thuringiensis israelensis (Bti) dunks, which kill mosquito larvae without harming other wildlife. Use EPA-registered repellents containing DEET, picaridin, or oil of lemon eucalyptus when outdoors. For persistent mosquito problems, professional yard treatments can dramatically reduce adult populations. Pest Control Bros serves Maricopa, Chandler, Casa Grande, Tempe, Gilbert, and Mesa — contact us for a free consultation.