Bumble-sized white-faced bee-mimic fly. Botfly?
June 2, 2010
Saw several of these large bee-mimicing flies feeding on a flowering tree. Looked through 9 pages of bee mimics on WTB and didn’t anyone quite like it.
The bristly hairs on the back end seemed botfly-like to me, but google hasn’t turned up a winner there either.
Thanks for your help,
This is a Tachinid Fly, Belvosia borealis, and we matched it quickly to a photo on BugGuide. According to BugGuide: “Larval stages are parasitoids of other insects. Almost every order of insects is attacked by tachinids, including a few types of non-insect arthropods. Some tachinids are very specific and others can parasitize a wide variety of hosts. The most common hosts are caterpillars.” BugGuide also indicates: “Most tachinids deposit their eggs directly on the body of their host, and it is not uncommon to see caterpillars with several tachinid eggs on them. Upon hatching the larva usually burrows into its host and feeds internally. When fully developed it leaves the host and pupates nearby. Some tachinids lay their eggs on foliage; the larvae are flattened and are called planidia; they remain on the foliage until they find a suitable host.“
Their hosts would have to be something pretty meaty considering the size of the fly, will keep an eye on that tree this season and see what else grows there.
Thanks very much.