100 Species #45: March fly

[urbpan]

Alexis encountered this female March fly (I'm saying Bibio femoratus, see below for discussion) as it lumbered slothfully about the back yard.

First, to any Australian entomologists who may be reading this, no this is obviously not what is called a March fly in that country. What you call a March fly--a large fly that takes big painful bites of humans and other mammals--we call a horse fly. Second, since there are entomologists reading this, Australian and otherwise, I am taking a foolhardy risk in attempting to identify it to species.

But, hey, that's what I do. Last time I encountered flies that looked like this was almost exactly one year ago. I declared it a love bug, and made it #12 in my 50 more urban species project. As time has gone by, I've become dubious that I was seeing love bugs--they are subtropical insects, and aren't known to come to New England. Instead, having spent some time researching and looking at bugguide.net, I think these are red-legged March flies. They are in the same family as love bugs, but are known to live in the northeast.

They emerge from the ground in early spring, before many predators are active. They mate (rather conspicuously at times), feed on flower nectar and aiding pollination, lay eggs in the soil, and die. The larvae are entirely subterranean, feeding on organic material in the soil. Males and females have very different shaped heads, with large eyes almost taking up the male's entire head. The main difference, from a human perspective, between love bugs and March flies is that while many March flies may appear at once, they do not seem to occur in the plague-like numbers that distinguish love bugs.

Comments

[ndozo.livejournal.com]

But do these splatter on cars the way love bugs do? A friend driving down from Syracuse last week encountered so many bugs he had to stop and clean off the windshield. I said then they sounded like love bugs, but I thought they were just a southern thing. Maybe it was these guys?

[urbpan.livejournal.com]

It could have been, I guess. There are lots of different seasonal irruptions of insects that happen. I wouldn't guess what your friend encountered without seeing them.