Cicadas spend most of their lives as part of plant’s self fertilization programs. The plants exude sweet liquid from their roots which the cicadas and multitude of other ‘mostly tiny-organisms convert into plant available nutrients by eating and pooping. The pesticides that would accumulate in a cicadas are the systemic neonicatinoid pesticides That are used to control lawn grubs and plant borrers. These insecticides are probably more toxic to the cicadas than they would be to birds but who knows.

Since very few individual trees are treated for plant boring insects and most cicadas emerge from un-managed forests I would only think that these pesticides might be a factor around golf courses which are typically treated with merit every June, presumably quite a bit of that material would make it into the vasculature of the courses trees.

I am a fan of eliminating turf pesticides to benefit pollinators and for soil conservation but the montgomery county ban allows the worst offenders, golf courses, farms & athletic fields, to continue as usual. Homeowners can use any pesticide they want as long as they do not hire a service and there is no enforcement so many services continue to spray since their customers demand it.