Thread subject: Diptera.info :: Ball-Head Fly From Swarm
Posted by Stephen on 06-11-2006 00:27
#1
Flies are usually scarce by November in West Virginia, but we had a warm and sunny day and the March Flies were swarming.
Talk about a mis-named family?March was eight months ago! What an interesting ball-like head!
As I watched, the flies would light on the dead leaves on the ground, or occasionally on a stick. Several times I saw what I presumed were two males in a territorial skirmish, pushing each other, etc.
Male March Fly, right? Genus Bibio?
Photo taken today, West Virginia USA, in woodlands. Length 7.3 mm from the front of the eyes to the rear of the abdomen.
Edited by Stephen on 06-11-2006 04:18
Posted by Stephen on 06-11-2006 00:28
#2
A more detailed view of the front of the fly.
Posted by Stephen on 06-11-2006 01:40
#3
I was surprised to see this two-parted design for the eyes, but when I got home I read about it in a field guide description of Bibio flies.
Edited by Stephen on 06-11-2006 04:16
Posted by Robert Nash on 06-11-2006 11:17
#4
This curious division of the eyes in this instance with smaller facets below (am I right?) is also found in Simuliidae and in the Gyrinidae (Coleoptera) or whirligig beetles where beetle, presumably sees above and below the water on which it gyrates the but that is all I know.Excellent photos :p:p also showing the prominent apical processes on the fore tibiae which distinguish this genus from
Dilophus in Ireland, although I see Arnett :p:p and Nearctica.com list 6 North America genera:
Bibio,
Bibiodes,
Dilophus,
Hesperinus,
Penthetria,
Plecia. Arnett lists 78 North American species. The oddly named love bug (see glossary vernacular names is in this last genus.
Slainte Robert
Edited by Robert Nash on 07-11-2006 10:50
Posted by Robert Nash on 06-11-2006 11:40
#5
The eye form is, I see, associated with swarming. A quick google search led to
Zeil, J. (1983). Sexual dimorphism in the visual system of flies: the free flightbehaviour of male bibionidae (diptera).
J. Comp. Physiol. 150, 395-412.An extract can be read at :-
Extract
http://www.spring...4m5281848/
Posted by Stephen on 07-11-2006 21:34
#6
Thanks, Robert! I have long wanted to photograph the double-eyes of Gyrinidae. Since I always try to photograph live creatures, I'm sure it will be a challenge.
Thanks for the citation--what amazing research with the two movie cameras! I understood a little less than half of the synopsis.
Anyhow, with so many March Flies here, I guess if I keep my eyes open long enough I will eventually find a female to photograph, or better yet, a pair.
During the last two days I took a number of pictures of the males pushing each other around, on the ground, but so far these action pictures aren't very sharp!