Just walking around my yard and photographing the things that I notice is teaching me so much these days. I often don't realize what I'm seeing until I get inside, download the photos, and take a closer look. This post describes a case in point....
As I was looking over the asters in my front garden one evening in late July (and wishing this species bloomed before late September!), I noticed an odd insect "knot" down in a dark recess of leaves and stems. As I tried to get a little closer to figure out what I was actually seeing, the "insect knot" flew a foot or two sideways, into an area with much better light, resolving itself into a robber fly with something in its grasp. I dutifully took a couple photos, then moved on to find other interesting subjects around the yard.
Like all robber flies, hanging thieves have piercing mouthparts. Once they capture their prey, they inject saliva, filled with digestive enzymes, into the unfortunate insect, let the saliva liquify the insides of said insect, and suck their juicy meal back out.
This final photo is focused on the prey, the wasp, rather than on the predator, the robber fly.
The balance of nature is a complex thing. The caterpillars eat the plants. The paper nest wasps eat both the plants (nectar) and the caterpillars. The hanging thieves eat the paper nest wasps. Hanging thieves lay their eggs in the ground. It's not known for sure what their larvae eat, but they are presumed to be predaceous on other soil invertebrates.
Have you seen any hanging thieves around your garden?