+ Introduction
+ History
+ Morphology
+ Terminology
+ Phylogeny
+ Distribution
+ Ecology
+ Biology
     + Immatures
     + Foraging
     + Prey
     + Courtship
     + Oviposition
     + Mimicry
+ Collecting
+ Determination
+ Photography
+ References

Information on Robber Flies

HULL (1962): "As regard mimicry in this family, it seems less well marked than is found in the Syrphid flies or butterflies. Melin (1923) does not accept the existence of mimicry in the Asilidae, but in this I believe that he is mistaken. Species exhibiting mimicry increase in hot, humid latitudes and may be quite lacking in the temperate lands. Shelford (1902) calls attention to a species of Laphria Meigen resembling the Hymenopteron Salius seriocosoma; and also Hyperechia fera Wulp resembling the bee Xylocopa latipes. An African species of Hyperechia Schiner was noted by Marshall (1902) to closely resemble the bee Xylocopa flavorufa.

Hyperechia bifasciata from Africa Xylocopa caffra from Africa
Hyperechia bifasciata from Africa Xylocopa caffra from Africa

The Amazonian species of Dasyllis Loew, which resembles bees of the group Eulaema and the various species of Diogmites Loew and Blepharepium Rondani, which resemble some species of wasps, may be considered examples of mimicry. The small asilid Megaphorus clausicella Macquart from the southern United States is a good mimic of Megachile bees. These examples are generally regarded as falling in the principle of synaposematic mimicry, or mimicry of aggressive resemblances. Both Shelford (1902) and Poulton (1925) have made contributions on this subject. Agressive mimicry favors aggression and offers a measure of protection from certain enemies. Some species produce a loud buzzing sound in flight not unlike some bumblebees. The curious Chilean asilid Lycomya germainii Bigot has for its model the Hymenopteron Elaphroptera scoliaeformis Haliday.

Dasyllis haemorrhoa from Brazil Eulaema cf. bombiformis from Brazil
Dasyllis haemorrhoa from Brazil Eulaema cf. bombiformis from Brazil
The American series of mimics from the southwestern states copy the tarantula huntung wasps of the genus Pepsis Fabricius. These noteworthy insects are large, with black or blue-black bodies and wings strikingly colored a yellowish brown. Besides the robber fly Asilus midas Brauer, the series contains Mydas xanthopterus Loew, two large staphylinid beetles, and a large, conspicuous ichneumonid-type wasp. In southern Arizona Blepharepium secabilis Walker occurs in company with a similarly colored sphecid wasp upon which it preys; the wasp is a little larger than the fly.
Cryptic coloration exists in some forms. Desert species especially tend to match the sandy background and many Laphriini and species of the Atomosiini and species of Andrenosoma Rondani match the bark on which they rest.
Death feigning has been observed in some captured asilids and has been remarked by Teale. I have noted that Proctacanthus milbertii Macquart may remain in catalepsy from several seconds to several minutes. How often this state is reached or occurs under natural conditions isnot known.



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Compiled by: F. Geller-Grimm