Variability of wings pattern of the locusts from the tribe Bryodemini Bey-Bienko (Orthoptera: Acrididae)

Abstract

Variability of the pattern of distribution of dark pigment and colouring of the wings Bryodemella tuberculatum (Fabricius, 1775), Bryodema luctuosum (Stoll, 1813), B. gebleri (Fischer-Waldheim, 1836) and Angaracris barabensis (Pallas, 1773) were studied. It was found that the pattern on the wings in the species of B. tuberculatum, B. luctuosum, B. gebleri is species-specific, but subjected to considerable variability. The most extreme variants, with clear contours are well distinguishable; however, forms with transitional morphological features fuzzy boundaries of the patterns were detected. Among the species of B. tuberculatum, B. luctuosum, B. gebleri, a vague resemblance to variants of the patterns on the wings was noted. It is possible that in this case «the law of homologous series» established by N.I. Vavilov in 1920 is demonstrated. According to this law, the variability of the closely related genera and species goes in common (parallel) way. Within the genus Angaracris Bey-Bienko,1930, the pattern and coloration of the wings is most strongly affected by the variability. However, the available material including published data from China allow creating transitional rows from most aberrant to typical forms. The opinion is expressed about necessity of taxonomic revision of the genus Angaracris.