Tuesday: 26 January 2010
The deer remains I described last week have attracted some unbearably cute midwinter insect opportunists. These are fairly tiny flies, 2 or 3 mm, and these photos are the best out of three attempts over the past week. Perhaps there is a sufficient variety to give some impression. Alternative suggestions are welcome - these were fairly difficult to match up with the photos of others.
This first species was certainly pert enough, with their outsized antennae pointed boldly forward and upward (note the hairlike aristae). And they run about the bones with amazing speed, even in the cool fifty degree weather.
The antennae bring me to Prochyliza maybe xanthostoma, aka skipper flies. Apparently they’re also called waltzing flies, because the males hold each other’s forelegs while dancing around in a circle. It must have been a little too cool for courtship posturing because I didn’t catch them doing this.
I notice that a number of the photos at Bugguide were obtained at carrion bait, which sounds like an interesting idea.
I’ve only managed to get these poor photos, a week ago, when temperatures were in the sixties, and I’ve been sitting on them since, an almost impossible task for me. It’s been colder and/or rainy since, and they haven’t made an encore appearance. Maybe we’ll get some warmer days and I’ll keep trying for a better set.
Both Acaplytratae: (top) Piophilidae (Tephritoidea), (bottom) Sepsidae
This first species was certainly pert enough, with their outsized antennae pointed boldly forward and upward (note the hairlike aristae). And they run about the bones with amazing speed, even in the cool fifty degree weather.
The antennae bring me to Prochyliza maybe xanthostoma, aka skipper flies. Apparently they’re also called waltzing flies, because the males hold each other’s forelegs while dancing around in a circle. It must have been a little too cool for courtship posturing because I didn’t catch them doing this.
I notice that a number of the photos at Bugguide were obtained at carrion bait, which sounds like an interesting idea.
 | No mention is made of waltzing here, but there was a considerable amount of interaction among these equally tiny insects, as you see to the left. They fly at each other and then spread their wings while doing a little grappling behavior. Cute! The closest I can come here, assuming these are flies at all, is Sepsis spp. Also called black scavenger flies, they are equally attracted to rotting meat, and worse! It was the presentation of the wings with their pigment spots, along with the wasplike body shape, that suggests this ID. For all I know they could be wasps, but in the lower left photo there’s a hint of a flyish head. |
I’ve only managed to get these poor photos, a week ago, when temperatures were in the sixties, and I’ve been sitting on them since, an almost impossible task for me. It’s been colder and/or rainy since, and they haven’t made an encore appearance. Maybe we’ll get some warmer days and I’ll keep trying for a better set.
Both Acaplytratae: (top) Piophilidae (Tephritoidea), (bottom) Sepsidae
