Simulium sp. B

The number and arrangement of gill filaments are similar to those of S. sp. A. However the larva can be distinguished from that of S. sp. A by the deep postgenal cleft, almost reaching the posterior border of the hypostoma, and a thick covering of unbranched and two­ and three­branched setae on the abdomen (Fig. 2 J).

All 3 larvae were analyzed for major landmarks. The centromere regions are not expanded. The IIS arm has the ring of Balbiani located basally and the bulge located somewhat centrally (Figure 1 K).