This year a number of persons reported to me that when their neighbors started with mosquito and tick control pesticide applications, they no longer have bees or butterflies in their yards. Even if they have lots of bee and butterfly friendly flowers, or lots of clover - they now rarely or never see bees and butterflies. This has also been my experience.
As I reported last year, this is because mosquito/tick services use pesticides that are highly toxic to bees and butterflies. The applicators hold pesticide sprayers at waist height that spray insecticides out at high volume, and usually walk along a property 's perimeter spraying. Looks like leaf blowers blowing out pesticides!
Typically pyrethroid and cypermethrin insecticides (e.g. made by Fendona) are used. These are broad-spectrum (kill many species, including bees), microencapsulated, long-lasting (up to 90 days) pesticides, and applications are usually every 3 weeks. So it's actually an over-application of the pesticides.
I observed an applicator walking along a neighbor's yard perimeter applying the insecticides at waist height directly into my hedges (yes, it is obvious to the applicator that they are on my property). As he walked along, I could see the hedges violently shaking from the high volume application.
By the way, that is a deliberate non-target application of pesticides, which is against the law in my state. But it's what these companies do with impunity - go look at their web-site photos. By the way, pesticide contamination of adjacent properties will always be a problem in suburban yards with this kind of application.
Bees are pollinators, and unfortunately they are in serious decline in the United States. Pesticides are a big cause. Pesticides, including pyrethroids, also have numerous health effects on humans - none of them good. Especially worrisome is exposure during pregnancy or in young children.
Interestingly, others and I have also noticed that bird species that were common in our yards no longer visit once a neighbor starts with the mosquito and tick pesticide applications. Hummingbirds, gold finches, black-capped chickadees, juncos, robins, song sparrows and other birds - all are now missing from yards.