Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

Spring 2021 gathering in Louisiana, April 28-May 2. Here's how to add your images.

National Moth Week 2020 photos of insects and people.

Photos of insects and people from the 2019 BugGuide Gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Black fly - female

Black fly - Female
Brimfield State Forest, Hampden County, Massachusetts, USA
April 26, 2010

Images of this individual: tag all
Black fly - female Black fly - female

Moved from Flies.

I was swarmed by black flies in Brimfield State Forest on Saturday.

I think this is a Prosimulium but I'm not sure. If it's biting you it's female.

What details would you need to see to know for sure?

Is Rs forked or not? The branches can be very close together.

Simulium has basal R cell 1/4 or less wing length and Rs not forked.

Other Simuliini have normal length R cell (~1/3 wing length) and Rs not forked or only forked for a very short distance at the tip.

Prosimuliini have normal length R cell and Rs forked about half its length with branches possibly very close together.

I can almost imagine there being very close branches, but I guess I'll have to try harder for a perfectly dorsal shot next time. At least they're good at holding still!

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.