Missouri Master Naturalists- Springfield Plateau Chapter

Friday, August 25, 2017

Horse Fly


We wrote about the bolete mushrooms on the glade in the last blog..  The day suddenly turned ugly as I was writing on the mushroom.  I heard a menacing buzz and felt a sharp pain on my back.    From then on for the next 20 minutes I had a dark Horse Fly  circling me and landing between my shoulder blades every minute biting me through my tee-shirt.  Swatting at it with my slouch hat had no effect as it followed me for a hundred yards.

Usually in encounter them on the creek and getting about 20 feet from their territory gets them off my case.  Not so this time as it followed me for several hundred yards through the woods, constantly buzzing and when silent it had landed and was biting through my sweat soaked tee-shirt.

Horse Fly - REK
I generally love nature in all forms.  We watch timber rattlesnakes by the garden and nudge them on their way.  We transfer spiders out of the sinks and haul rat snakes out of our attic at intervals.  When possible I capture insects, cool them in the refrigerator (thank you Barb for your tolerance) and photograph them alive before releasing them back to nature.  However I have to admit that I thoroughly enjoyed putting a pin through this bugger.

In the last blog I said we were "Blood Brothers" but not exactly, more like blood siblings.  Only the female bites, acquiring blood as a high-protein food needed for egg production.  I would happily take out a hard boiled egg or even a piece of last nights beef dinner for her but she is very specialized and wants only mammal blood.  Horse, deer or me, it makes little difference to her.

"The better to bite you with, my dear!" - REK
Adults wide ranging as this one was 150 feet above the creek bed.  The larvae live mostly in wet soil along the margins of streams and ponds.  While adult females feed on vertebrate blood, usually of warm-blooded animals, males and a few female species visit flowers.  Their larva are mainly carnivorous.  The female is well equipped to draw blood from the thick hide of a horse or the thinner skin of the primitive bipeds that came across the land bridge 13,000 years ago to provide an alternative blood source.
Wikipedia with annotations
"The bite is effected by stabbing with the mouth parts and slicing the skin with scissor-like movements of the finely serrate, knife-like mandibles and smaller maxillae. After capillaries are ruptured, anti-coagulant saliva is pumped out through the hypopharynx, and the blood is lapped up using the labella." from Bugguide
I have to admit that after my experience on the trail it gave me great pleasure to pin this Horse Fly for the upcoming Master Naturalist training where we will be using it for insect taxonomy.  It is not about revenge.....OK, maybe a little.
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Horse Fly in Wikipedia
More on the Tabanidae Family,  commonly known as horse flies, and deer flies