254 W. A. LAMBORN. 



and 10 females having been bred out. The tsetses which have emerged from the 

 1,143 living pupae which I have obtained since 10th April number 54 males and 

 71 females. 



The appearance presented by a pupa-case from which a Mutillid parasite has 

 emerged seem to me characteristic and unmistakable, though, a contrary opinion 

 has recently been expressed (Eminson, quoted in Bull. Ent. Ees., v, p. 382). On 

 taking such a case in the fingers there is, owing to the presence of the Mutilla cocoon 

 within, a sense of greater solidity than when a fly has emerged, and it is possible by 

 gentle pressure to crumble away the wall of the puparium so as to obtain the cocoon, 

 a light chestnut-coloured structure composed of several layers of a very tough 

 silky-looking material. The orifice of exit is usually much smaller and has a serrate 

 edge, instead of the larger clean-cut fracture produced by the emergence of the 

 fly, owing to the parasite having nibbled out a circular cap, and one can always 

 see the walls of the cocoon within. In the course of time the cocoon tends to shrink, 

 the result being that it draws in with it the margin of the hole of exit in the 

 pupa-case, so that this is no longer circular but somewhat oval, a condition never 

 seen in the case of a normal puparium 



There has been no difficulty at all in dealing with the Mutillids in captivity, for 

 all, except two, one of which was accidentally drowned, are still alive now, one or two 

 of the earliest specimens being several weeks old. The original male placed in a 

 box with the female shortly after the emergence of the latter manifested the greatest 

 excitement, running about with its antennae on the ground on the track of the 

 female, which it overtook after a considerable chase and immediately seized, pairing 

 taking place almost at once. It is noteworthy that in the course of the chase it ran 

 repeatedly very near to the female, but being of! the fresh track did not detect it, 

 the sense of sight being evidently of very little help to it in the matter. 



Various pairs have been kept in captivity in jars containing a number of tsetse 

 pupae buried in earth, in the hope that the females would sooner or later parasitise 

 them. This expectation seems likely to be fulfilled, as on 30th May the first female, 

 which, emerged so long ago as the 3rd of that month, was actually witnessed 

 ovipositing in one of the pupae. As the manner in which oviposition was effected 

 presented features of interest, I jotted down at the time a full note concerning it, 

 which I now transcribe : — ^At 5.45 p.m., on coming into camp from a day's trek, 

 I removed from inside a box, which had been closed all day, a jar containing the 

 Mutilla female, no. 1, and a number of tsetse pupae, mostly buried in earth, though 

 one or two were on the surface. On the top of one of the latter the Mutilla was 

 seen. It remained still a few seconds, then precipitately vanished beneath a lump 

 of earth, as is their habit when alarmed. In a few minutes it came out into the open 

 again cautiously, and after examining with its antennae some pupae near the one 

 on which I had first seen it, started, with its head facing the tail end of the pupa, to 

 whittle away with its jaws at a point midway between the two poles with such 

 energy as to rock it. Its antennae were crossed and below its head. After five 

 minutes' work in the horizontal position it gradually raised itself vertically, with 

 its head down on the pupa, supporting itself against the side of the jar, so that a 

 full view of its movements with a lens could readily be obtained. Extremely fine 

 movements of the jaws in and out took place with great rapidity and with such 



