112 



This strain of S. metallica was maintained in the laboratory for seven 

 months without any visible effects resulting from the close inbreeding. 

 Isolated pairs did not breed rapidly ; the females fed reluctantly and 

 eggs were deposited at irregular intervals. The larvae were able to 

 develop both in a highly nitrogenous, dark brown medium, or in tap 

 water with a layer of sand at the bottom. The duration of the develop- 

 mental stages was as follows : — Egg, seven days ; larval, ten days ; 

 pupa, three days. Stegomyia luteoce])hala, Newst., was found in the 

 gutters of two bungalows at Accra ; the water was slightly turbid 

 and contained decaying vegetable matter. Ochlerotatus irritans, Theo., 

 occurred in small pools near the lagoon at Accra ; the water contained 

 about 2 '2 per cent, of salt. 0. sudanensis, Theo., together with larvae 

 of AnoijJieles costalis, Culex insignis and Uranofaenia annulata, was 

 found in crab holes along the sides of the stream at Sunyani ; the 

 water always contained much suspended matter. Culex pruina, Theo., 

 -and Eretmopodites inornatus were present in water containing decaying 

 vegetable matter, found in a hollow in the concrete foundation for the 

 erection of a pump. Culex insignis, Cart., occurred in crab holes 

 containing water with much suspended matter. C. ingrami, Edw., 

 was f ouncl in deep clear pools in the thick forest. C. consitnilis, Newst. , 

 was present in masses of filmy algae in clear water. Larvae and pupae 

 of Eumelanomyia inconspicuosa, Theo., occurred in clear water in the 

 hollow of a fallen tree. Mimomyia hispida, Theo., together with 

 larvae of M. plumosa and Uranotaenia alhoabdominalis, was found in 

 marshy ground along the edge of the stream at Sunyani., The position 

 of these species in Edwards' " Kevised Keys to the known larvae 

 of African Culicinae " {Bull. Entom. Research, iii, pp. 373-385) is 

 indicated as far as possible. 



Johnston (J. E. L.). A Summary of an Entomological Survey of 

 Kaduna District, Northern Nigeria. — Bull. Entom. Research, 

 London, vii, no. 1, May 1916, pp. 19-28, 2 figs., 2 tables. 



This paper describes an entomological survey of the Kaduna District 

 and the site of the future capital of Nigeria. Special attention was 

 paid to the presence of Glossina and the resulting trypanosome diseases 

 of cattle. Tsetse-flies were very scarce in the district, possibly owing 

 to the dry season, though a few examples of Glossina palpalis and 

 G. tachinoides were obtained. Stomoxys spp., especially S. nigra and 

 S. calcitrans, were abundant. Though it has been shown that Trypano- 

 soma nigeriense will develop in the gut of S. nigra, it is more probable 

 that cattle were infected by Glossina near the streams. Of the total 

 number of cattle examined, 12 '6 per cent, were infected with trypano- 

 somes and 26 per cent, with piroplasmata, while one sheep out of 12 

 examined showed piroplasmata. The trypanosome causing infection 

 was mostly of the T. vivax type. 



The commonest mosquito was C. nebulosa (.51 'SS per cent.), while 

 Anopheles costalis and Culex duttoyii ranked second (14' 19 per cent.). 

 The remaining 19'7 per cent, consisted of :■ — Stegomyia fasciafa, 

 S. simpsoni, S. sugens, S. africana, Culex decens, C. fatig%ns, C. tigripes, 

 C. annulioris, Ochlerotatus cumminsi, and Mansonioides uniformis. 

 Other blood-sucking flies and ticks collected, included :■ — Tabanidae : 

 Haematopota gracilis, Aust. ; H. lacessens, Aust. ; H. pertinens, 



