Subject: Fly in the forest
Geographic location of the bug: Olalla, Washington
Date: 03/07/2018
Time: 09:00 PM EDT
Your letter to the bugman: Hi. This fly was sitting on a coltsfoot leaf in the forest on a chilly day (maybe 48°). I love the brown hairs on his thorax. What is he?
How you want your letter signed: gardenjim
Dear Gardenjim,
Though the wings on your individual are smokier than we are used to seeing on a Drone Fly, we believe that is a correct identification for your fly. The wing veination pattern on your individual matches that of this Drone Fly pictured on BugGuide as well as that of this Drone Fly pictured on BugGuide. The Drone Fly is an Old World species that has naturalized in North America and it ranges from coast to coast. The larva of a Drone Fly is known as a Rat Tailed Maggot.
Update: Cesar Crash of Insetologia provided a comment and correction. This appears to be a species of Hover Fly in the genus Brachypalpus from the same subfamily as the Drone Fly and there is an undescribed species posted to BugGuide from the same region as this sighting.
The wings don’t have the stron curve in the R4+5 of the Eristalines:
http://drawwing.org/insect/eristalis-tenax-wing-0
strong*
But it seems tha Brachypalpus spp. and their kin are Eristaline without this:
https://bugguide.net/node/view/718306/bgpage
https://bugguide.net/node/view/11726/bgpage
Thanks for the correction Cesar. The Drone Fly seemed close, but not quite right. BugGuide does have this undescribed member of the genus Brachypalpus pictured that is from the same general region as the posted sighting.
This is Brachypalpus alopex to be specific. The undescribed species is boreal and east of the Rockies.
Thanks for that information. We have updated the posting.