135 



various Blow-flies, such as Calliphora, Liicilia, Sarcophaga, Chrysomyia, 

 etc., these would be distributed a few days before emergence of the 

 parasites, being either scattered by hand in the Glossina haunts, or 



, placed in small masses lightly covered with humus to protect them 

 from predators. This method, applied to permanent breeding grounds 

 of limited extent, would, in Roubaud's opinion, undoubtedly offer an 



appreciable check to the increase of Glossina. 



Some years ago it was urged by Austen and Bagshawe (5) that it 

 would be well worth while to endeavour to establish the various 

 American species of the genus Spalangia (Family Chalcididae) in a 

 Glossina morsitans area, and to watch the result. One of these minute 



, Hymenoptera (Spalangia muscidarum) " has been bred in large numbers 

 from the puparia of Stomoxys calcitrans," and, with other species of the 

 same genus, " also attacks the pupae of other flies, including Musca 

 domestica and Lyperosia irritans." 



As to the possibility of obtaining assistance from Hymenopterous 



i parasites in reducing the numbers of G. palpalis, it must be admitted 



, that recent statements by Fiske (54) are not encouraging. Writing 

 with reference to the islands and shores of Lake Victoria, in Uganda, 

 this author says : " The parasitism of puparia of Glossina palpalis in 

 good breeding grounds by Hymenoptera was found to be absolutely 

 negligible. The only instance encountered was on Wema Island, 



i where in a catch of 203 puparia, three were found attacked by a small 

 gregarious Chalcid. A percentage of parasitism at this point of 1 5 



; was thus indicated. At other points near at hand enough more 

 unbroken puparia were collected and examined to make a total of 1 ,775, 

 and not another parasitic specimen was found. From other points, 

 first and last, more than 3,000 living puparia were collected and 

 examined, making some 5,000 in all, and no other case of parasitism 

 was encountered. 



" Occasionally empty shells are found with small round holes such 

 as are left by Hymenopterous parasites in emerging, but except at the 

 one point noted above, examination of such shells has never disclosed 

 the characteristic (and unmistakable) exuviae of such parasites. The 

 selected breeding grounds of the species are practically absolute 

 protection against this class of destructors. 



" The parasite discovered on Wema bred with the greatest freedom on 

 puparia of Glossina in confinement. About one month was required 

 for the generation. It could be an enemy if it would, but its instincts 

 lead it elsewhere than in the breeding places of Glossina in search 

 of prey." 



PARASITES OF THE ADULT FLIES. The parasites that attack Tsetse- 

 flies in the adult state may be divided into external parasites and 

 internal parasites. 



So far as we are aware, the only external parasites hitherto recorded 

 are those met with in Northern Nigeria by Dr. J. W. Scott Macfie. 

 Writing in 1913 with reference to the Ilorin Province, Dr. Macfie says 

 (94) : " On a few specimens of both G. palpalis and G. tachinoides, 

 taken during the months of May, June and August, minute red mites 

 were found attached to the abdomen, thorax or legs. They were 

 easily detached by the point of a brush, and in one instance the mite 

 voluntarily left the tsetse-fly and was found crawling over the floor of 

 a store-box. They were of two distinct types, and although at the 

 same seasons other mites were common on such insects as mosquitos, 



