207 



It is known that the parasites of puparia of tsetse flies are fairly 

 numerous and that in some areas they exert a considerable influence 

 in reducing their numbers. While various explanations have been 

 given for remarkable diminution in the numbers of Glossina in certain 

 districts without there being any marked diminution in the numbers 

 of game animals therein, the author suggests that the local extermina- 

 tion of the flies may be due to the activities of their parasites. This 

 process seems to be steadily proceeding in the district indicated, and 

 the question naturally arises how far it may be possible to increase 

 the influence of parasites, either by the introduction of new ones or by 

 breeding on a larger scale those already known to science. 



As the genus Glossina is now limited to the Ethiopian region, it is 

 doubtfid how far the parasites of other Diptera, brought in from other 

 lands, would seek out and destroy its puparia. It seems likely that 

 those obtained from the puparia of other Muscids, breeding under 

 more or less similar conditions, might do so, or other species naturally 

 parasitic on Glossina, but having a difi'erent geographical distribution, 

 might give greater success. For example, the Bombyliid, Villa lloydi, 

 Aust., parasitic on G. morsitans, has as yet only been found in Rhodesia, 

 and a second species of parasitic Mutillid, M. henefactrix, Turner, 

 only in Nyasaland. The parasites that occur on the west coast of 

 Africa are probably difterent from those in the east and south, the 

 insect fauna as a whole being difiierent. It is thought, therefore, 

 that the various species of tsetse-flies may each have different parasites, 

 which have not yet been discovered, and which might be interchange- 

 able. It is probable that some of the parasites of tsetse-flies, with 

 less powers of flight than their hosts, have been left behind in the 

 first foci inhabited by the flies ; this is particularly likely with Mutillids, 

 the females of. which are wingless. The advisability of enhancing 

 the value of the parasites already known to science, in particular the 

 Chalcids, is pointed out. These could readily be bred in the laboratory 

 on the puparia of their natural host, or, as these are rather limited, 

 on those of some of the common Muscids as alternative hosts. 

 Some research has been done in regard to suitable alternative hosts, 

 and though the work has been brought to a premature close, the 

 results show some promise and will be published later. 



BoRNAND (M.). L'Hypoderme du Boeuf et ses Consequences au 



Point de Vue 6conomique.— P;oces- Fer6. Bull. Soc. Vaud. Sci. 



Nat., Lausanne, liii, no. 198, 15th Sept. 1920, pp. 55-58. 



Almost 80 per cent, of the cattle of the Jura and the Alps are 



infested with the larvae of Hypoderma bovis. The author has never 



met with the larvae on cattle that remain in the plains during the 



summer months. It is particularly the young animals that are 



attacked, and the numbers of larvae found on one of these may be 



as many as 500. The financial loss caused by this fly in Denmark, 



Switzerland and Germany is enormous, since hides badly riddled 



by the larva lose half their value. 



Ludlow (C. S.). Siberian Anopheles. — Psyche, Boston, Mass., xxvii, 

 no. 4, August 1920, pp. 74-78. 



The new mosquitos here described from Siberia are Anopheles 

 lewisi and A. selengensis. 



