Subject: Short wasp? Weird bee? Sawfly? Just what is this guy?
Geographic location of the bug: La Jolla, California
Date: 09/19/2017
Time: 06:10 PM EDT
Hello there. I was wondering if you could identify this insect? I am terribly afraid of bees and wasps, so when I took a glance at it after stepping out of my mother’s car (about 6 meters away), I was in a hurry to get away from it. Upon closer inspection, my mother insisted it looked more like a moth than a bee (I have to disagree, but the wings do have peculiar patterns that bees, wasps, and the like usually don’t have, so I guess I could see it.)
It certainly did not fly like a butterfly- it hovered much like a bee or wasp would when it would fly, which is why I thought it was one until I saw the pictures she took.
This fellow was attracted to some yellow flowers we have right outside of our house, (the kind of flower is featured in one picture of the bug) if that means anything at all. Yet again, bees and butterflies also tend to hang out there, so I guess that’s nothing really important, although it lets you know this guy’s a pollinator.
Anyways, if you could help me identify this bug I would so much appreciate it. I’ve tried looking everywhere to find his species and have had no luck.
Thank you kindly.
How you want your letter signed: T.H.
Dear T.H.,
Mistaking this Bee Fly in the family Bombyliidae for a bee is quite understandable. It is quite a beautiful Bee Fly and we suspect it is the same species that visited the offices of What’s That Bug? this weekend in the Mount Washington neighborhood of Los Angeles, but alas, we were unable to get an image of it before it flew away. We have identified it as Poecilanthrax arethusa thanks to the Natural History of Orange County site. Unfortunately, other than providing a range, BugGuide does not have any species specific information on this gorgeous, and perfectly harmless, Bee Fly, but the genus page does credit D. Yeates with the revelation “Endoparasitoids of Noctuidae pupae.” We followed the provided link to ResearchGate where it states: “The recorded host range of Bombyliidae spans seven insect Orders and the Araneae; almost half of all records are from bees and wasps (Hymenoptera). No Bombyliidae have evolved structures to inject eggs directly into the host as is the case in many hymenopterous parasitoids. Bombyliid larvae usually exhibit hypermetamorphosis, and contact their host while it is in the larval stage. Bee fly larvae consume the host when it is in a quiescent stage such as the mature larva, prepupa or pupa.” The indicated hosts, the pupae of moths in the family Noctuidae, generally pupate underground. INaturalist has numerous Southern California sightings.