Currently viewing the category: "Thick Headed Flies"
What's That Bug? does not endorse extermination

Thick-headed fly
July 11, 2010
Thick-headed fly
Sure thought this was a smallish wasp, but finally found out it’s a thick-headed fly. Thought you might like a picture.
Sara
NJ

Thick Headed Fly

Hi Sara,
As we were working on your post, we realized we needed to create a new category for Thick Headed Flies.  We will need to search through our archives to see if we have any older postings of Thick Headed Flies in the family Conopidae, but this might be a first for our website.  We believe your specimen may be in the genus
Physocephala, which BugGuide describes as “adults feed on flower nectar  Females usually oviposit on hosts (mostly bumble bees and wasps) during flight. Larvae become internal parasitoids (usually kill the host).”  There is additional clarification of the life cycle on BugGuide:  “P. tibialis has been reported to parasitize workers of the bumble bee Bombus bimaculatus. Adults apparently alight and inject an egg into the abdomen of their host while in flight.  A study in Alberta showed that bumble bees parasitized by P. texana had the same lifespan as unparasitized individuals (Otterstatter et al, 2002; …).

Ed. Note: A previous posting of a Thick Headed Fly from 2009 was added to the new category.


What's That Bug? does not endorse extermination

Thick-headed fly
July 25, 2009
Here is a photo I took today. Went to Buguide. It was identified as a conopidae, species unknown. Posably physoconops, or physocephala.
Terry Sincheff
Mound, MN

Thick Headed Fly

Thick Headed Fly

Dear Terry,
Thanks so much for sending us your photo of a Thick Headed Fly.  WE are linking to the BugGuide information page that states:  “The adults are usually found on flowers.  Food  Larvae are endoparasites, chiefly of adult bumblebees and wasps. Adults take nectar.

What's That Bug? does not endorse extermination