145 



in the use of material limed on the under side carried in a horizontal 

 position, but the results were not so satisfactory as when the material 

 was carried in a vertical position." 



The following extract from " Suggestions for Future Work," by 

 Austen and Bagshawe (5), is perhaps also worth noting. " Correct 

 conclusions as to the value of trapping and catching cannot be deduced 

 from a trial lasting only two or three months, in which but a handful 

 of natives are engaged ; the value of limed cloths and of nets in the 

 hands of expert fly-boys should be tested in a selected locality for at 

 least a year, and on a large scale. Some hundreds of natives should be 

 employed in the work, and a corps of, say, a dozen keen and energetic 

 fly-boys should be established in each village in a tsetse area. Payment 

 should be by results, but small rewards would suffice, and the system 

 should therefore prove inexpensive in working." 



It has been pointed out by Simpson (144) that in wide areas of 

 Tsetse-infested country, such as occur in the West African colonies, 

 systematic trapping of Glossina is impracticable. " Systematic 

 trapping with bird-lime," when tried by this author in the Gold Coast, 

 was " found to be less satisfactory than by means of nets. Four colours 

 of paper were used light brown, red, black waterproof, and green. 

 These were most satisfactory in the order given." 



A trap suggested by Dr. J. O. Shircore (140) for use against G. 

 morsitans, based on the known habits of this species, consists of a series 

 of revolving canvas screens, smeared with adhesives and placed on 

 routes known to be frequented by the fly. A later idea of the same 

 author (141) is that logs, covered with some adhesive substance and 

 propped on supports two or three inches off the ground, might act as 

 effective traps. We are unaware whether either of these suggestions 

 has yet been submitted to a practical test. 



OTHER METHODS OF CATCHING AND DESTROYING TSETSE-FLIES. 



A study of the tropisms, or physiological reactions, to which the 

 genus Glossina, like all other insects, is subject, would perhaps lead to 

 the discovery of an effective plan of campaign against these Diptera. 

 In endeavouring to construct serviceable insect-traps, it is always well 

 to bear in mind the special attraction exerted by light and by odours ; 

 in the case of Tsetse-flies investigations are needed to discover some 

 specially attractive substance. 



About ten years ago Dr. Andrew Balfour, C.B., C.M.G., had some 

 large Tsetse-fly traps constructed by the Andres Maire Company, with 

 a view to their being tested in Western Mongalla (Egyptian Sudan). 

 Writing in 1913 of the experiments that it was intended to carry out 

 with these traps, Dr. Balfour remarks 1 : 



" As regards methods of attraction, the following measures will be 

 tried : 



"1. Soaking the central bands or wicks in a mixture of water and 



either human or animal sweat. 

 "2. Placing a live animal in the trap .... 

 " 3. Soaking the central bands in citrated blood, and at the same 



time hanging up in the trap a piece of fresh meat from ox 



or buck with skin still adherent. 



1 Annals of Tropical Medicine and Parasitology, Series T.M. Vol. VII. no. 1, 

 p. 119 (March 31, 1913). 



(5979) K 



