CARRIERS OF FILARIA IOQ 



of such streams could only be undertaken where there 

 was a large settlement. 



(2) Mansonoides uniformis requires for its development 

 and greatest activity a high temperature and a moist 

 atmosphere, just the conditions under which mosquito- 

 proof houses are least popular. Mosquito nets and 

 mosquito-proof houses are the only satisfactory method 

 of preventing the infection where it is absolutely neces- 

 sary that such a site has to be chosen for a habitation. 

 This mosquito is a dangerous carrier of filariasis in small 

 settlements on the banks of large rivers and lakes. 



During the daytime the mosquitoes rest amongst the 

 vegetation, and the vicinity of the house should therefore 

 be kept as clear as possible from long grass and bush. 



Fumigation of the inhabited rooms of houses from 

 shortly before to two hours after dusk with burning 

 pyrethrum will very much diminish the number of 

 mosquitoes which enter the houses. 



(3) Stegomyia pseudoscutellaris (fig. 48) closely re- 

 sembles S. scutellaris, but the thoracic markings are 

 more extensive, especially laterally, and the abdominal 

 bands are incomplete. The larvae are also similar, but 

 the spines on the penultimate abdominal segment are 

 different. In habits the imago differs, as it is a pure day 

 feeder and the larvae are found in brackish water near 

 the coast, whilst S. scutellaris is a jungle mosquito in the 

 main, and feeds at night even more than in the day. 

 It does not occur in Fiji. 



Destruction of larvae is not easy, as thorough drainage 

 of low-lying land near the coast is difficult. Bahr in 

 closed places had some success with copper sulphate, 

 i gr. to 437 gallons, but it is only larvicidal to the freshly 

 hatched larvae ; the more mature larvae can thrive in the 

 solution if vegetable food is abundant. 



