Re: Where do mosquitoes go during the day in the summertime?

Female mosquitoes (the ones that bite), as well as males, usually find 
places to rest during the day. Males may swarm at dusk and females go on 
their blood-seeking missions utilizing carbon dioxide emissions of the 
victims to locate potential blood meals. I have seen huge numbers of 
female Anopheles crucians resting under wooden swamp walkways during the 
winter in Florida.  Some female mosquitoes (such as Aedes albopictus- the 
Asian tiger mosquito) will bite during the day, at least when it is cloudy 
or in the shade, so they are not always inactive in daylight hours.  
Others may cluster in tree holes or in vegetation.
References:

Aedes albopictus http://www.fact-index.com/a/ae/aedes_albopictus.html

Adult mosquito (CMMCP) http://www.cmmcp.org/adult.htm

Mosquitoes (University of Missouri Extension) http://muextension.missouri.edu/explore/agguides/pests/g07400.htm

Mosquitoes in Maricopa County  http://www.maricopa.gov/envsvc/WATER/VECTOR/mc-mosquitoes.asp