Hi Chandlergardner,

Palo Verde beetles emerge during our summer monsoon season and can be a frightening sight on warm evenings. The larvae, which are a huge 3" whiteish grub, live inside the roots of trees for several years before maturing into the black adult beetle. The holes they leave in the ground are about the size of a quarter in diameter. They seem especially attracted to the imported Mexican Palo Verde tree, but will munch on nearly any non-native tree or shrub species including Mulberry and Ash.

Another insect that active during the monsoon season is the cicada. They produces the loud buzzing you hear in trees this time of year leave 1 inch diameter holes in the ground. Female cicadas lay their eggs on branch tips which causes die-back.

The best management for these insects is to keep your trees as healthy as possible. Deep, infrequent watering and minimal pruning will enable plants to resist attack by these pests.

Here is a link that might be useful: Palo Verde Borer Beetle

you may be able to control them with neemseak nematodes
go to www.arbico.com
it is in tucson az