124 



HEPORT OF THE ENTOMOLOGICAL SECTION 



Marked 



differences 



between lar\al 



stage of 



T. kiiigi and 



T. ticniola 



Description 

 of larva of 

 7'. kitii^i 



I left Khai'toum on April 28, and on my return on May 30, the majority of these larvoe 

 were dead — one, however, had completed its life-cycle and seven were still living. Six 

 of these seven pupated during the next three weeks but died as pupae. The pupal period is 

 probably about six days, for one which pupated on May 5 appeared to be mature on 

 May 11, when it perished. 



One empty pupal case was taken under a stone in the bed of the Khor Arbat stream — 

 the fly must have crept up the stone through several inches of running water before 

 gaining the air. 



Although this tabanid in its adult form closely resembles T. taeniola, Pal. de Beauv., 

 in its larval stage it differs markedly from that species. The larva is admirably adapted 

 for clinging to stones in rapidly running water, its unusually long pseudopods, armed with 

 powerful hooks, being retractile and capable of being used as suckers. None of the 

 tabanid larva; which I have seen hitherto have possessed an anal proleg. 



Besides the seven specimens mentioned above as having been taken in the act of 

 ovipositing, two more were caught sucking blood from camels. No males were seen. 

 Descriptionr: — 



Egg. — Length, 2 nun. Colour white, becoming darker as the embryo within develops. 

 Spindle-shaped. 



Mature larva (Plate V., figs. 11, 13-15). Length, 35 mm. Colour, pale grey to dusky- 

 grey to deep chestnut-brown. Mandibles, dark brown to black, long and powerful, 

 slightly serrated. Anterior margins of meso- and meta-thoracic segments dark. A smooth 

 shiny pale area ou the dorsum of each thoracic segment — on the prothorax this 

 area is concave anteriorly, convex posteriorly and with parallel sides ; on the meso- and 

 meta-thoracic segments it appears to the naked eye diamond-shaped, though sometimes 

 it is actually hexagonal. On the venter of the prothorax are two shiny pale longitudinal 

 areas, each bearing several long black hairs arising from a single pore ; a similar but 

 larger area is striated on each of the meso- and meta-thoracic segments, bearing two 

 similar tufts of hair. On either side of the meso- and meta-thoracic segments are three 

 longitudinal areas not extending to the margins of the segments, longitudinally and deeply 

 striated. On the anterior margins of the meso- and meta-thoracic segments on either side 

 are four paler lines extending backwards to form the divisions and edges of the three 

 striated areas. On the anterior third of each abdominal segment except the eighth is 

 a ring of pseudopods, eight in each ring — two dorsal, two lateral, four ventral — except on 

 the first segment where the dorsal pair is wanting. The dorsal pseudopods are never well 

 developed, and, with the exception of those on the fifth, sixth and seventh segments, 

 unprovided with hooks. The lateral and ventral pseudopods are very long and liear at 

 the apices long, strong hooks, chestnut-brown in colour, sometimes darker at the tips. 

 On the median pair of ventral pseudopods on the fourth, fifth and sixth segments these 

 hooks form a complete circle, but on the remaining pseudopods bearing hooks the circle 

 is incomplete. Immediately below these hooks is a row of tiny spines. Immediately 

 behind the ventral pseudopods on the first to the seventh segments inclusive is a shiny 

 striated area. On the venter of the eighth segment, anteriorly placed to the anus, is a 

 pseudopod equal in size and similar to the ventral pseudopods on the other segments, 

 and bearing an incomplete circle of hooks. Scattered over the surface of the larva are 

 occasional black hairs. The siphon, when exserted, is shorter than the eighth segment, 

 and bears a number of black hairs. The dark appearance of the larva is due to tiny dots 

 of pubescence arranged closely together, except on the shiny areas mentioned above. 



The skin of the larva frequently bears scars of old wounds. 



