44 MALARIA 



The movements of Anopheline larvae are very much 

 more jerky than the Culicine, the wriggling motion 

 of the latter being wormlike. The former are also 

 not so easily seen as the latter, probably due to their 

 horizontal position in the water. On wading into a 

 swamp there may be no larvae visible, but on turning 

 around and looking into the muddy water caused by 

 wading, the larvae are plainly seen, i.e. distinctly out- 

 lined against the now yellowish background. 



A close examination of the feeding Anopheline larvae 

 will show that the head is turned dorsally and the 

 smaller organisms (animal and vegetable) near the sur- 

 face form the main objects of diet. The Culicine larvae 

 usually feed on organisms deeper down and in the 

 edges of the pools, after going down in search of these 

 objects. 



The Pupae. - -The pupae, or nymphs (Fig. 20, c), of 

 all mosquitoes are very similar. In all cases, instead 

 of the single posterior breathing apparatus of the larva, 

 there are present a pair of breathing trumpets located on 

 the thorax, i.e. anteriorly. The position of these trum- 

 pets in the two groups of mosquitoes is different and 

 fairly distinctive, i.e. they are located farther forward 

 on the thorax in Anophelinae, near the middle, and open 

 broadly in this group, being more slender and relatively 

 longer in the Culicinae. 



In position also the two groups differ somewhat, i.e. 

 the Anopheline pupae hang more horizontally and the 

 heavier head end is relatively longer. 



