Horse Fly

Subject: Loud & Fast; Scares the Dog
Location: Missouri, 60 miles from St Louis
September 30, 2013 2:31 am
Several of these show up around our house each spring-early fall. They will hover in place for a while, then take off really fast, zooming around for a while before suddenly stopping to hover in place. The hum/buzz of their wings is loud, my dog even refuses to go outside when he hears them. They fly very fast when they aren’t hovering (my grandpa started calling them ’bullet bugs’). I finally managed to catch one with a grocery bag so I could photograph it. If you can identify it, I’d love to know what this is that scares my dog (and if he has good reason to be scared!)
Signature: Cassie

Horse Fly
Horse Fly

Dear Cassie,
This is a Horse Fly in the family Tabanidae, and according to BugGuide:  “Females (but not males) suck vertebrate blood which they need to produce eggs.”  We are not certain of the species, but your individual resembles 
Tabanus calens which is pictured on BugGuide.  Your individual appears to be a male, which will not bite.  If you dog has had a bad experience with one or more females buzzing prior to biting, you dog might be remembering the experience.  Horse Flies generally feed on livestock, but when livestock is not available, other warm blooded prey, including humans, will suffice.

Thanks so much for that! I searched around for a while trying to find out what they are, but didn’t have luck. I’m usually better at identification when it comes to spiders (Love them so much).
Next time I get really good spider pics, I’ll be sharing them like I did my fishing spider before.

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