A hideous Giant Black Horsefly (Tabanus atratus) landed in the cab of the Camp Salmen truck the other day and went right for the back glass. It buzzed around back there, seemingly fixated on the space, daylight and freedom imminently apparent beyond the invisible barrier. Rather than chasing it around the cab, the door was simply left open at the next stop. The fly was still there a short while later, too stuck on stupid to look around and try something imaginative like flying out of the open cab, so since it couldn’t make up its mind, the intense heat that would quickly build up inside the parked truck certainly would.
One of the reasons they have the name they do are the poor horses they torment. Sometimes these poor beasts seem sadly resigned to the constant assault from the insect and barely bothered to flinch. The Black Horsefly can and will attack a human but it’s not common. They would probably rather do it to a quiet horse than a fidgety human with hypersensitive skin and swift hands on the ends of long, articulated arms. Plus horseflies aren’t too swift.
Like many other parasitic, stinging insects, it’s the female that is responsible for these vicious attacks and is after a blood meal for producing her eggs. Her brutal technique is to jab a sharp, serrated, piercing and cutting instrument into the flesh of her victim in order to draw blood and soak it up with a sponge-like mouth tool. This can be a time-consuming procedure, which is another reason they’d prefer a horse. Oddly enough, the male of the species is just as big, black and nasty-looking as the female but has a different set of mouth tools and instead, spends his days idly lapping up nectar and pollen from flowers, right along with the butterflies.
Horseflies lay their eggs in aquatic environments like a stream bank or a pond’s edge. Their larvae can also bite, but having yet to develop legs or wings to move about they’re not much of a threat. However, since the sweet things will cannibalize other horsefly larvae they tend to grow up alone and retain the antisocial attitude of a true punk.