A neighbor contacted Tempe Neighborhood Services (TNS) about an unusually large number of paper wasps (a.k.a. hornets) being present. We have noticed this ourselves, and have literally suffered the sting of it (they don't take kindly to being grasped, even if all you want is to pick that zucchini). It's possible that the absence of a hard freeze this winter allowed the queens to overwinter.
In any event, TNS would like to let everyone know that property owners are responsible for the hornet nests on their properties. BUT, general application of insecticide will not get rid of the hornets - the nests must be destroyed.
In my experience, this species of hornet is not particularly aggressive (ref. killer bees), but they do deserve respect and proper distance. Also, the workers return to the nest in the evening and they are relatively quiescent after dark. I have destroyed several in our yard over the years, some with canned insecticide sprays designed for this purpose (direct application to the nest by shooting a jet of insecticide), but more frequently by spraying a strong enough jet of water from the hose to soak the nest and break it apart. (If it's located in a bush or something, I expose the nest with a loooong pole.)
Doing it yourself is a risky proposition, so if you have any doubts about doing it or are highly allergic to insect stings, hire a professional. There's plenty of them out there and eradicating hornets from your property is not a difficult task for them.
