GLOSSINA INVESTIGATIONS IN NYAS ALAND. 33 



best method of dealing with captured specimens of Thyridanthrax abruptiis, a 

 Bombyliid fly parasitic on G. morsitans, in the hope of elucidating its life-history. 

 From these pupae, which were set aside after having been kept with a succession of 

 Bombyliids, no less thai^ 41 Mutillids, 19 males and 22 females, have emerged to date 

 (16th October), apart from nine Bombyliids which may or may not be the outcome 

 of the experiment, and only 11 tsetses, five males and six females. 



Seeing that the Mutillids are now emerging in such numbers from pupae obtained 

 near Monkey Bay, it is not a little remarkable that only two parasites, one a Mutillid 

 and the other a Bombyliid, have emerged from pupae obtained within the proclaimed 

 area, though in all 368 living pupae were found in various localities within the area. 

 Their comparative rarity there has been confirmed by an examination of the 4,192 

 cases obtained at the same time, none of which showed evidence of parasitism. 



A second Mutillid Parasite.^ 



Several specimens of an entirely different species of Muiilla have recently emerged 

 from pupae found at Monkey Bay many weeks ago, though in two cases only is the 

 precise date available. These pupae were found on 22nd May, and from one of them 

 a male MnlUla emerged on 9th October and from the other a female on the following 

 day. The remaining pupae parasitised by this insect were found before 2nd June, 

 and the parasites, four females and four or five males, emerged between 16th August 

 and 9th September. 



The males of the new species present a close general similarity to the males of 

 M. glossinae, though differing in build, being much slighter ; but the females present 

 a totally different abdominal pattern, in addition to being smaller. Their specifiiQ 

 difference is shown by the total neglect of the females by the males of M. cjlossinm^ 

 which seize instantly any newly emerged female with the right pattern, for no court- 

 ship takes place. The new species exhibits in both sexes a far greater restlessness 

 and activity than M. glossinae, the males of the former taking to flight on the slightesfc 

 chance of escape, whereas the males of the latter species rarely do so unless they feel 

 a sudden stir of air. As a preliminary to coitus the male M. glossinae grips the female 

 round the neck with his mandibles, girdling her body with his legs. The attitude 

 in the case of the new male is different, for he secures his partner with his mandibles 

 round the abdominal pedicle. As with other species of Mutilla, the males of both 

 attempt at times to bear away the female on the wing, a habit probably playing an 

 important part in ensuring the distribution of the species. 1 have several times 

 taken males and females together in the air, and on one occasion found two in coitu 

 on a blade of grass standing in the lake some little way from the shore, whither the 

 female could only have been transported by the male. 



There is good reason to hope that morsitans pupae have been experimentally 

 parasitised by these insects also, for a number of them to which females of the Mutilla 

 have had access exhibit at a point midway between the poles the tiny shining and 

 rather sticky patch which one sees sometimes also in the case of pupae parasitised by 

 M. glossinae. 



[*This species is described on p. 93 by Mr. R. E. Turner as Mutilla henefactrix, 

 sp. nov. — -Ed.] 



(C250) . c 



