Platystomatidae (Diptera), Signal Flies

Platystomatidae (Signal flies) are distinctive acalyptrate flies, ranging from small (2.5 mm), slender species to large (20 mm), robust individuals. Body colours frequently have a distinctive metallic lustre. Face and wings are usually patterned with dark spots or bands and many bizarre forms of morphology occur in this family. Heads and fore legs, especially, may be oddly shaped, extended in various ways or with adornments, all of which serve to supplement agonistic (fighting, sparring and dueling) behaviour *.

Many genera of the family prefer shaded, densely vegetated locations, resting on the underside of foliage (pers. obs.) or displaying on the top-side (photo). The legs or the wings are often held up at an acute angle and waved around in signalling motions for sexual display as can be seen in the photograph of Peltacanthina albolineata below.

The biology of Platystomatidae is poorly known and our knowledge of the biology and immature stages (larvae) is even less well understood. Platystomatidae appear to have an association with ripe or rotting fruit, carrion, dung and other items of decay, where eggs are laid and the larvae develop. Some species are pests in things like peanuts and rooibos tea, where the larvae develop in the nitrogen rich root nodules.

The family is placed in the Superfamily Tephritoidea. There are about 120 genera Worldwide, including nearly 1200 species. The majority of species are found in the African and Australasian tropics, with lower numbers known from South-east Asia, Pacific and Indian Ocean islands, the Americas and finally reaching the lowers numbers in Europe and Central Asia.

* References

McAlpine, D.K. 1973. Observations on sexual behaviour in some Australian Platystomatidae (Diptera, Schizophora). Records of the Australian Museum 29(1): 1-10.

McAlpine, D.K. 1975. Combat between males of Pogonortalis doclea (Diptera, Platystomatidae) and its relation to structural modification. Australian Entomological Magazine 2(5): 104-107.

McAlpine, D.K. 1979. Agonistic behavior in Achias australis (Diptera, Platystomatidae) and the significance of eyestalks. p. 221-230. In: Blum, M. S. and Blum, N. A. (eds). Sexual selection and reproductive competition in insects. Academic Press, New York.  463pp.

McAlpine, D. K  1994.  Review of the species of Achias (Diptera: Platystomatidae).  Invertebrate Taxonomy 8(1): 117-281.

Whittington, A.E. 2003. Taxonomic revision of the Afrotropical Plastotephritinae (Diptera; Platystomatidae). Studia Dipterologica Supplement 12: 1-300.

Whittington, A.E. 2006. Extreme head morphology in Plastotephritinae (Diptera, Platystomatidae), with a proposition of classification of head structures in Acalyptrate Diptera. Instrumenta Biodiversitatis VII: 61-83.