Untoward effects of mosquito spraying
The answer depends on the product that they use to spray for the mosquitos and how they use it. The product label will tell you if the active ingredient is harmful to wildlife such as pollinators and birds. You can find a lot of information on pesticides on the National Pesticide Information Center website: http://npic.orst.edu . If the product is toxic to pollinators, the homeowner can take measures to reduce harm to pollinators. Examples include: 1. Not spraying flowering plants. 2. Removing flowers from plants prior to spraying. 3. Spraying at night when bees are not active.
Of course the best thing for the bees is to not spray at all or to use a product that is least toxic to pollinators.
This MSU Extension publication (E3245) contains a table of common insecticide active ingredients and their relative toxicity to bees: https://www.canr.msu.edu/uploads/resources/pdfs/Minimizing_Pesticide_Risk_to_Bees_in_Fruit_Crops_(E3...
This MSU Extension article also has some good info on how to protect yourself from mosquitos: https://www.canr.msu.edu/news/what_can_i_do_about_the_mosquito_super_emergence