A Note on Simulium bancrofti, Taylor, with the Description of a new Species of Simulium (Dipt.)

Abstract

Simulium bancrofti, Taylor (Plate V, figs. 1–5).Head : Width of the frons slightly less than half that of the whole head ; antennae short, about two-thirds the width of the head ; first three segments cyathiform, the first slightly broader than long, a little less than half the length, and slightly more than half the width of the third ; second segment one-third longer than wide ; segments 4–7 inclusive approximately the same length ; the fourth a little wider than segments 5–7, which are all of about the same width ; penultimate longer than 4–7 individually ; apical segment moderately long and somewhat cone-shaped. Palpi five-jointed ; first joint cyathiform, with an apical row of four bristles, the two outer ones longer than the second segment ; the latter oblong, its sides nearly parallel, also with an apical row of bristles of about the length of the inner two on the first segment ; first and second segments together half the length of the third, the latter somewhat obovate, tapering slightly distally ; fourth almost pear-shaped, tapering basally, shorter than the third (11 : 14) ; fifth fusiform, tapering to a blunt point at both extremities and very little longer than the third, with a few scattered hairs, especially on its apex. Legs : fore femora and tibiae dilated ; first tarsal joint tapering very slightly at its base, a little more than half the length of the tibia (27 : 46), outer edge with a dense fringe of spinules, except on its basal fifth, apex with a stout spine on its outer apical angle ; base of second joint narrower than apex, lower surface with numerous spinules, especially on the distal two-thirds, apex with two stout spines, one on either side ; third and fourth joints cyathiform, the former one-third longer than the latter ; fourth with a deep median depression for almost half the length of the tarsus, forming the socket of the fifth ; third joint with numerous spinules on its distal two-thirds and an apical row of moderately long spines, the outermost the longest ; fourth joint sparsely covered with fairly long hairs, apex with four long, stout bristles, two on either side of the base of the fifth joint ; the latter pear-shaped, a little more than twice the length of the fourth, with a few fairly long hairs on its distal half ; claws short, almost straight, not toothed. Mid leg with the tibiae dilated, with a long, stout, external, apical spine ; first tarsal joint not dilated, a fringe of spinules along its outer margin and a few scattered ones over its ventral surface ; second joint with the spinules on the outer margin increasing in length and stoutness apically ; third joint similar to that of fore leg and without spinules ; fourth and fifth similar to those of fore leg ; joints 2 to 5 distinctly hairy.