Posts Tagged ‘Tabanus calens’

I don’t think so!

March 25, 2019

A horse fly, possibly Tabanus calens, was spotted after a long photowalk at Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA. This individual is a female, as indicated by her eyes.

Males have eyes that meet along a seam down the middle of the head (holoptic eyes); females have eyes that are well-separated. Source Credit: Benjamin A. Coulter, member of the BugGuide group on Facebook.

21 SEP 2016 | Occoquan Bay NWR | horse fly (female)

A wider view shows the horse fly is perched on my Honda Civic, just above the handle of the driver’s side front door. Male horse flies don’t bite; females bite, painfully!

Adult horse flies feed on nectar and sometimes pollen. Females of most species are anautogenous, meaning they require a blood meal before they are able to reproduce effectively, if at all. Much like male mosquitoes, male Tabanidae are not ectoparasitic and lack the mouth parts (mandibles) that the females use in drawing the blood on which they feed. Most female horse flies feed on mammalian blood, but some species are known to feed on birds or reptiles. Some are said to attack amphibians as well. Source Credit: Horse-fly, from Wikipedia.

21 SEP 2016 | Occoquan Bay NWR | horse fly (female)

I shooed the fly away from the front door handle, but she didn’t go far. She landed on the Honda logo on the trunk of my car — still too close for comfort! I’m happy to report I was able to get into my car without being bitten.

21 SEP 2016 | Occoquan Bay NWR | horse fly (female)

Copyright © 2019 Walter Sanford. All rights reserved.

The real monsters of Huntley Meadows

September 19, 2014

Longtime residents of eastern Fairfax County, Virginia USA may recall reading about the “Mount Vernon Monster” that reportedly roamed the region during the late 1970s. Although I have neither seen nor heard the monster, I jokingly reply “Bigfoot” whenever people pass me at Huntley Meadows Park and ask whether I shot any good photographs. But seriously, folks — there are real monsters at the park, including horse flies and robber flies.

The following photos show two horse flies, possibly Tabanus calens, spotted during recent photowalks along the boardwalk in the central wetland area. Both individuals are females. Male horse flies don’t bite; females bite, painfully!

Adult horse flies feed on nectar and sometimes pollen. Females of most species are anautogenous, meaning they require a blood meal before they are able to reproduce effectively, if at all. Much like male mosquitoes, male Tabanidae are not ectoparasitic and lack the mouth parts (mandibles) that the females use in drawing the blood on which they feed. Most female horse flies feed on mammalian blood, but some species are known to feed on birds or reptiles. Some are said to attack amphibians as well. Source Credit: Horse-fly, from Wikipedia.

Horse fly (female)

17 September 2014. Photo 1. Horse fly (female).

Males have eyes that meet along a seam down the middle of the head (holoptic eyes); females have eyes that are well-separated. Source Credit: Benjamin A. Coulter, member of the BugGuide group on Facebook.

Horse fly (female)

17 September 2014. Photo 2. Horse fly (female).

The next gallery shows another female horse fly spotted along the boardwalk on 15 September 2014.

The last photo shows a Red-footed Cannibalfly (Promachus rufipes), a species of robber fly spotted near the beginning of the boardwalk.

Red-footed Cannibalfly (Promachus rufipes)

10 September 2014. Red-footed Cannibalfly (female).

Robber flies feed mainly on other insects. (Whew, that’s a relief!)

The fly attacks its prey by stabbing it with its short, strong proboscis injecting the victim with saliva containing neurotoxic and proteolytic enzymes which very rapidly paralyze the victim and soon digest the insides; the fly then sucks the liquefied material through the proboscis. Source Credit: Asilidae, from Wikipedia.

There are “approximately 1,040 species of robber flies in approximately 100 genera in our area.” Source Credit: Family Asilidae – Robber Flies, from BugGuide. Thanks to Mike Powell, fellow wildlife photographer and blogger, for identifying the species of robber fly shown above!

Copyright © 2014 Walter Sanford. All rights reserved.

Beauty and the Beast

February 8, 2014

Beauty. Beautiful dragonflies. Make more, please!

The following photos show a mating pair of Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum) spotted during a photowalk through Huntley Meadows Park. The male is on top; the female on the bottom. The female is a heteromorph.

19 September 2013. Close.

19 September 2013. Close.

Blue-faced Meadowhawk dragonflies (mating pair)

19 September 2013. Closer.

19 September 2013. Closest.

19 September 2013. Closest.

The Beast. Blood-sucking pests. Go away and leave me alone!

Horse flies, possibly Tabanus calens, tormented me at times when I was hunting Blue-faced Meadowhawk dragonflies at Huntley Meadows Park. Male horse flies don’t bite; females bite, painfully!

18 September 2013. Male horse fly (Tabanus calens).

18 September 2013. Horse fly (male).

Males have eyes that meet along a seam down the middle of the head (holoptic eyes); females have eyes that are well-separated. Source Credit: Benjamin A. Coulter, member of the BugGuide group on Facebook.

20 September 2013. Female horse fly (Tabanus calens).

20 September 2013. Photo 1. Horse fly (female).

20 September 2013. Photo 2. Horse fly (female).

20 September 2013. Photo 2. Horse fly (female).

The back-story: On 19 September 2013, I was hunting Blue-faced Meadowhawk dragonflies at a place along the boardwalk that had been a lucky spot for a few days. An especially aggressive horse fly forced me to flee to a new location on the boardwalk. Seconds later, I spotted the first mating pair of Blue-faced Meadowhawks I had ever seen! So as it turns out I’m indebted to horse flies, in a weird twist of fate.

Thanks to Ben Coulter for identifying my tormenters and for explaining how to recognize male- and female horse flies — now I know which ones to beware of!

Copyright © 2014 Walter Sanford. All rights reserved.


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