Bengalia is a genus of blow flies in the family Calliphoridae with one authority considering the genus to belong to a separate family Bengaliidae. These bristly and, unlike the greens and blues of most calliphorids, dull coloured flies, are especially noted for their relationship to ants. Little is known of their biology and life-cycle, although adults of many species are kleptoparasitic on ants and will snatch food and pupae being carried by ants or feed on winged termites. The apt name “Highwayman Fly” was given by an early observer of their way of robbing ants. Very little is known about their breeding habits. The genus is found in the Afrotropical and oriental region with one species from Australia possibly a recent introduction.
Description
Most of the species have a yellow or brown ground-colour, an antero-posteriorly compressed head, stout mouthparts, a projecting clypeus below the lower facial margin, and have a silent flight.
Behaviour
Bengalia flies are best known for their remarkable highwayman-like habit of robbing ant pupae from ants moving on ant roads. With respect to Bengalia depressa this habit is described as follows: “[The flies were] settling on blades of grass, stones, and other raised objects near the ant column. ... When any ant made a little circuit away from the main body, a fly would generally pursue it at a distance of about half an inch, but back away as soon as the ant turned towards it. ... Eventually Lamborn saw a fly stalk a minor ant carrying a pupa in its jaws. Suddenly the fly rushed forward and apparently pierced the pupa bringing the ant up with a sharp jerk. The two insects then had a tug of war with very little advantage to either side, until the ant apparently became annoyed and letting go of the pupa rushed at the fly, which escaped with the booty which it proceeded to suck. Then he saw a fly swoop down on the ant column and rise at once with a pupa and attendant ant, both of which it dropped after carrying them for about a foot. The ant, however, still held on and started to run off with its charge. The fly caught it again and this time rose three feet in the air and then dropped ant and pupa again. This time the ant left the pupa which the fly immediately seized and proceeded to suck.”
Species
Bengalia africana Malloch, 1927
Bengalia africanoides Rognes
Bengalia akamanga (Lehrer) Bengalia aliena Malloch, 1927 Bengalia asymmetria Kurahashi & Tumrasvin, 1979 Bengalia bantuphalla (Lehrer) Bengalia bezzii Senior-White, 1923 Bengalia calilungae Rueda, 1985 Bengalia chekiangensis Fan Bengalia chiangmaiensis Kurahashi & Tumrasvin, 1979 Bengalia chromatella Séguy, 1946 Bengalia concava Malloch, 1927 Bengalia cuthbertsoni Zumpt, 1956 Bengalia depressa Walker, 1858 Bengalia emarginata Malloch Bengalia emarginatoides Rognes Bengalia emdeniella (Lehrer) Bengalia escheri Bezzi, 1913 Bengalia fani Feng & Wei Bengalia favillacea (Walker) Bengalia fernandiella Lehrer Bengalia floccosa Wulp Bengalia fuscipennis Bezzi, 1913 Bengalia gaillardi Sourcouf & Guyon, 1912 - Synonyms:B. spurca Brauer & Bergenstamm, 1891, B. spurca Villeneuve, 1914 Bengalia gigas Macquart Bengalia hastativentris Senior-White, 1923 Bengalia hobbyi Senior-White, 1940 Bengalia inermis Malloch, 1927 Bengalia jejuna Fabricius Bengalia kanoi Kurahashi & Magpayo, 2000 Bengalia kuyanianus Matsumura Bengalia labiata Robineau-Desvoidy, 1830 Bengalia lampunia Lehrer Bengalia lateralis Macquart Bengalia latro Meijere Bengalia lyneborgi James, 1966 Bengalia martinleakei Senior-White, 1930 Bengalia minor Malloch, 1927 Bengalia nirvanella Lehrer Bengalia pallidicoxa Senior-White, 1946 Bengalia peuhi Villeneuve, 1914 Bengalia pseudovaricolor Kurahashi & Tumrasvin, 1979 Bengalia pygomalaya Lehrer Bengalia racovitzai (Lehrer) Bengalia recurva Malloch, 1927 Bengalia robertsi Kurahashi, 1987 Bengalia roubaudi Rickenbach, Hamon & Mochet, 1960 Bengalia semerunia Lehrer Bengalia seniorwhitei (Lehrer) Bengalia siamensis Senior-White, 1924 Bengalia smarti (Lehrer) Bengalia spinifemorata Villeneuve, 1913 Bengalia subnitida James, 1964 Bengalia surcoufi Senior-White, 1923 Bengalia taiwanensis Fan, 1965 Bengalia taksina (Lehrer) Bengalia tibiaria Villeneuve, 1926 Bengalia torosa Wiedemann Bengalia unicolor Senior-White, 1946 Bengalia varicolor Fabricius, 1805 Bengalia wangariae (Lehrer) Bengalia weii Rognes Bengalia wyatti (Lehrer) Bengalia xanthopyga Senior-White, 1924 Bengalia zhangi (Lehrer & Wei)