172 THE EARLY STAGES OF TABANIDiE 



Scholtz (1850) reports that he has found the pupae, together with 

 those of Tabanus autumnalis and of Hccmatopota pluvialis in the 

 neighborhood of Breslau in June, 1850, at the edge of a pond cov- 

 ered with Zewwa, the water of which was polluted from manure piles 

 surrounding it. The pupae were found near the edge under a thick 

 mass of moist Lemna, together with Stratiomys — and Syrphus — 

 pupae ;^° the flies hatched after a few days. 



Tabanus ustus Walker. — An African species, observed by Neave in 

 enormous numbers around a pool in a nearly dry stream bed, on the 

 plains in Portuguese territory, southern Nyasaland. 



One male and three females were bred in the laboratory at the end 

 of October apd beginning of November. The larva, of which the 

 terminal segments are figured (Plate 5, Fig. 66), resembles that of 

 Tabanus biguttatus, but is less pigmented. 



The upper hooks of the pupal aster are considerably larger than the 

 remainder. The spines of the dorsolateral comb are much reduced, 

 especially in the male. 



The pupal aster of the male and the dorsolateral comb of both sexes 

 are figured (Plate 14, Fig. 177, a, b, c). 



Tabanus variabilis Loew.^ — An African species, not rare near Mt. 

 Mlanje, southern Nyasaland, on wooded streams in the neighborhood 

 of the mountain in October and November, occasionally later. 



The larvae were found in this locahty by Neave, in abundance. 

 They are entirely different from those of Tabanus atrimanus, being 

 almost colorless, though in quite mature individuals the base of the 

 syphon and the syphon itself are of an orange color. The most strik- 

 ing peculiarity of this larva is, however, the presence of a distinct 

 papilla of a dark color on each side of the anal segment. This is 

 easily recognizable in life and distinguishes this species from any 

 other seen by Neave. The anus is also unusually prominent. 



The pupa is also remarkable for its dark coloration, especially on 

 the dorsum of the thorax. The aster is characterized by the large 

 horizontally extended middle pair of hooks, and its outline is there- 

 fore entirely different from that of the closely allied Tabanus atri- 



30 See also pp. 72 and 91. 



