Weird happenings on a elm tree in a behind the scenes part of the zoo

I was called up to see a tree up in a non-public part of the zoo, which (the thought was) might have a hornet's nest in it. A hornet's nest in a tree is pretty obvious--either it's a big gray paper football, or it's hidden in a big dead cavity in the tree. This was a pretty small elm, with no big holes, no big paper nests, but plenty of wasps and hornets on and around it. However, there were other insects involved as well, such as this Calliphorid carrion fly.
( Collapse )