I'm concerned because I haven't seen any bees (or other beneficial insects--ladybugs, lacewings, etc) in my garden this summer. I have an organic lawn and vegetable garden and don't use any chemicals, but I know that there are people in my neighborhood who have their yards sprayed for mosquitoes (I've seen yard signs for Mosquito Joe). I have a wide row of raspberries in my garden and by this time I'm usually picking a full quart every day. This year I'm barely picking half a pint and it's obvious that the berries are poorly pollinated (small and not fully developed). Could backyard mosquito spraying be killing bees?
Insect populations are frequently locally abundant or sparse, and this may vary from year to year. It sounds as if this year the bee populations in your area are less than previous years. This is not necessarily true for the entire state or region. There have been many anecdotal comments among entomologists stating there appears to be a decrease in beneficial insects populations in landscapes receiving repeated mosquito sprays to the plants. My experience with mosquito management is very limited and my knowledge of application techniques and practices are also limited. I suspect that the daytime applications of mosquito control products to properties use a pyrethroid (broad spectrum insecticide) and this could have impacts on a variety of insects. However, without knowing when applications are made it is difficult to say if neighborhood applications are having an impact on pollinators. There are rules those companies should be following to minimize impact on pollinators and the great majority of those companies follow the rules. Applications to manage mosquitoes has occurred for years and typically occurs at night. Basically, I am unsure why you are seeing a decrease in beneficial insects and pollinators this year and there are a number of factors that can influence their abundance besides human impact (weather, plant variety and availability at crucial stages, etc...). A method to improve insect abundance in your landscape is to have variety of plants. This diversity brings in a variety of insects which in turn will attract more beneficial arthropods. I also suspect factors other than pollination can affect berry yield, but what those are I am unsure. Hopefully next year will have a greater number of insects visiting your plants.