128 THE EARLY STAGES OF TABANID.^ 



and slightly caudad of these is a transverse series of closely placed, very long, 

 slender bristles. Length at least 25 mm.; abdominal spiracles with very much 

 elongated vertical rima, the upper and lower extremities slightly curved forward. 

 The long spines on dorsal abdominal segments either black-tipped or all pale, 

 without a black preapical ring; short spines in anterior dorsal series slender and 

 very uneven. A small but distinct tubercle just in front of base of middle leg in 

 addition to and some distance above the one bearing the paired hairs." 



Malloch's material, which v^as partly the same as that collected 

 by Hart in 1895, contained only one specimen of nigrescens (in very 

 poor condition). 



The prothoracic spiracle of the pupa has been figured by Malloch 

 (Plate 13, Fig. 156). 



Tahanus ohscuripes Ricardo. — An African species, occurring in 

 southern Nyasaland, chiefly on the plains in Portuguese territory to 

 the east and south of Mt. Mlanje, in October and November. 



A single male was bred by Neave from a pupa collected on Octo- 

 ber 1. The pupal aster, which is figured (Plate 15, Fig. 183, a, h) 

 somewhat resembles that of Tahanus laverani and has the same large 

 middle pair of hooks. The dorsolateral comb is reduced to a single 

 knob-like process. 



Tahanus {N eotahanusY^ ochrophilus Lutz. — A common Brazilian 

 species. On its early stages we possess some notes by Lutz in Rio de 

 Janeiro (1914). 



Larvae of this species were found in muddy or sandy soil below and 

 at the sides of a small brook with slowly flowing water. Large 

 quantities of sand had to be sifted to obtain them. As food, tubi- 

 fex was given. The full grown larvae measured 30 mm. Color 

 creamy white, integument shining and transparent, intestine reddish 

 or blackish. Tracheag silvery. Mandibles dark, serrate beneath. 

 Digestion slow, four to five days. Before pupation, contracted; in 

 spontaneous death, expanded. 



Culture in moist sand, but for observation purposes moss in glass 

 jars was preferred. The larvae have to be kept in the dark during the 

 intervals of observation. The pupal stage lasted about ten days. 



^^ The few species of Neotahanus of which early stages are known are here class- 

 ified with Tahanus. There is no doubt that the genus Tahanus could be subdi- 

 vided into smaller genera or subgenera but opinions on this point are not definite. 



