256 W. A. LAMBORN. 



A Species of Bombyliid fly {Thyridanthrax abrupfus, Lw.)* a striking-looking insect, 

 quite distinct from the Villa lloydi found also to be parasitic on morsitans pupae 

 in Rhodesia, has been bred out from morsitans pupae here, three specimens having 

 been obtained. The first of these insects was discovered in early May in a jar 

 containing a number of tsetse pupae which had been buried beneath the earth. 

 The pupa-case of the Thyridanthrax was found on the surface, and I therefore 

 concluded that perhaps the pupa, having escaped notice, had been in the earth all 

 along and had no connection with the tsetse pupae. But since this I have been 

 keeping my pupae in rice to prevent them from rolling about when the boxes are 

 moved, and in these I found two more of the Bombyliids a short time ago, their puparia 

 being far removed from the tsetse pupae which they had originally occupied. The 

 empty tsetse puparia difier in no way from those from which tsetses have emerged, 

 other than in the absence of the cuticle which is found in the latter. 



This Bombyhid is by no means uncommon in the fly area, especially at Lingadzi, 

 so that I have been familiar with its appearance almost from the very first. I am 

 endeavouring to proceed further with an investigation into its habits. 



Within the last few days two nice-looking Chalcids [Stomatoceras micans, Wtrst.], 

 large insects with black markings on the wings, have emerged from tsetse pupae 

 through an opening situated in each case close to the tubercles at the posterior 

 end of the puparium. These also are thriving in captivity, but unfortunately appear 

 both to be of the same sex. 



In connexion with the question of Chalcids, I found in April in cattle droppings 

 a large number of pupae of a little Muscid [Musca sp. nov. ?] common in houses 

 in this country, and having bred out numerous small Chalcids [Spalangia sp.] from 

 them, endeavoured to parasitise tsetse pupae with them, but without result, so far 

 as I have yet been able to judge. 



A fourth species of parasite, an apterous insect,f has also been bred out 

 from a tsetse pupa. 



Examination of the living pupae recently collected, 1,143 in all, affords evidence 

 as to the probable parasitism of a small number, small marks Hke punctures being 

 visible with a high power lens, and a study of the empty cases found at the same 

 time, numbering 9,762, has afforded some statistics thereon, for owing to their 

 chitinous nature and the sheltered positions in which they are placed it appears 

 to be some time before the empty cases suffer by exposure. By far the greatest 

 number of cases (no less than 8,543) had given exit to perfect flies ; for though 

 there is no means of diflerentiating between normal pupae and those parasitised 

 by Bombyliids, the latter seem to be in so small a minority as to be almost neghgible 

 from the statistical point of view ; 351, or 3| per cent., showed that they had been 

 parasitised by Mutillids, the features characteristic of which have already been 



* [This species was bred from a G. morsitans pupa in Southern Rhodesia, in November 

 1912, by Mr. R. W. Jack. In Nyasaland, it was found in Mombera's district by 

 Dr. H. S. Stannus, and in North Nyasa by Dr. J. B. Davey. It has also been received 

 from Embu, Mt. Kenia, British East Africa {G. St. Orde Brown) and Minna, N. Nigeria 

 {Br. J. J, Simpson). — Ed.] 



t [This is a new and remarkable Chalcid, which will shortly be described by 

 Mr. J. Waterston under the name of Eupelminus tarsatus. — Ed.] 



