Promachus bastardiiASILIDAE (ROBBER FLY) PAGE

A Web Page by Roy J. Beckemeyer

Last updated: 25 September 2008

Photograph by Roy Beckemeyer --- Promachus bastardii (Macquart) 1838 (male) photographed 14 June, 2006 in Sim Park, Sedgwick County, Kansas.  Note the yellow hairs on the fore tarsi.

"Robber flies (Asilidae) are a widely distributed group of predatory flies which largely inhabit semi-arid and arid regions of the world." - Lavigne et al, 1978







LINK HERE FOR IMAGES OF Mallophora orcina taken 23 August, 2008 at Ninnescah Field Station



This robber fly, Diptera: Asilidae: Asilinae: Asilini: Wyliea mydas (Brauer) 1885, is a  spider wasp mimic (Hymenoptera: Pompilidae: Pepsis) .  Photographed along the San Francisco River in Catron County, New Mexico, near the Highway 180 bridge just west of the town of Luna, NM and just east of the Arizona border.   A most impressive and beautiful asilid.  Photographed 30 July, 2007 by Roy Beckemeyer.  See Martin, C. H., 1975, "The generic and specific characters of four old and six new Asilini genera in the western United States, Mexico and Central America (Diptera: Asilidae)".  Occasional Papers of the California Academy of Sciences, No. 19, 107 pp. (p. 78-79).  





LINK HERE for Photos of Museum Specimens of Wyliea mydas Provided by Fritz Geller-Grimm 







Promachus albifacies

Left: Specimen of male Promachus albifacies Williston, 1885, from Kansas State University collection.  Determined by J. Wilcox [Madera Canyon, Sant Rita Mountains, AZ, 1 June, 1961 leg. Rh & EM Painter]







A Prairie Robber Fly / Info on Kansas Robber Flies / Images of Robber Fly Specimens / Links to Other Robber Fly Sites 

Diogmites angustipennis with preyA Prairie Robber Fly:

The photo on the right shows a Diogmites angustipennis with a captured honey bee (Apis sp.).  The robber fly is hanging from the grass by its fore legs and holding and manipulating the prey with the other 4 legs.  Photographed at Pawnee Prairie Park, Wichita, August 2000 using a Nikon 200mm Macro lens in natural light, Fuji 100 slide film.  I have observed these insects a number of times this month as they selectively worked flower stands in search of hymenoptera.  They actively move around, responding to the arrival of new insects at the flowers by changing position and facing them.  I watched one fly at, then away from a bumblebee (Bombus sp.), apparently deciding it was too big.  Once they have a bee or wasp, they fly off into the grass to feed.  When disturbed, they fly away, but never climb very high or fly very far, appearing to have a tough time carrying the load.  Click HERE for a sketch of this robber fly based on a photograph taken at this location, and HERE for a look at the same sketch used as the Cover Illustration for Volume 33 of The Prairie Naturalist (Published by The North Dakota Natural Science Society).




Diogmites angustipennis

Left: Diogmites angustipennis Loew 1866 [Sugarland, TX, 2 July 1933, det by J. Wilcox, leg. R. Nabours/C. Sabrosky], KSU collection.

Right: Diogmites misellus Loew 1866 [Edgartwon, MA, 1 July 1922, leg. C. W. Johnson, det. J. WIlcox], KSU collection.






Photo, above right: Diptera: Asilidae: Asilinae: Apocleini: Triorla interrupta (male), photographed by Roy Beckemeyer 15 June, 2006 at Konza Prairie, Riley County, Kansas.

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SOME ROBBER FLY IMAGES (Video views of specimens taken through dissecting scope eyepiece at various magnifications; habitus photos Nikon D100 with 200 mm macro lens and flash)

Efferia albibarbus maleEfferia albibarbus female




















Above: Left - Anterio-lateral view of head and thorax; Center - Lateral habitus; Right - Dorsal habitus; Stichopogon pritchardi - Microphotographs taken through dissecting scope with Nikon 990 digital camera with flash.


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