151 



Malpighian tubules are given off at the junction of the 

 *' stomach " and the hind-gut ; the hind-gut consists of 

 an ileum, a colon, and a dilated rectum opening at the 

 anus. 



Embedded in the fatty body (in the haemocoele), above 

 the first pair of legs, there are two trilobed salivary glands ; 

 the ducts unite to form a common salivary duct which opens 

 into the base of the hypopharynx. The malaria germs 

 (sporozoites) are found in the salivary glands. 



The male mosquitoes have no mandibles, their maxillae 

 are very short, and the hypopharynx is fused with the 

 labium ; they cannot therefore pierce or "bite." 



How could you distinguish an Anopheline from a Culicine 

 Mosquito ? 



Their resting attitudes are different ; the Anopheline 

 rests with the body held out at an angle, and the proboscis 

 straight in front of the head ; the Culicine holds its body 

 parallel with the surface on which it rests, and the pro- 

 boscis is bent downwards. 



As a rule Anophelines have spotted wings, and the 

 maxillary palps and proboscis are about equal in length. 

 Culicines have palps shorter than the proboscis, in the fe- 

 male ; and longer than the proboscis, in the male. 



Briefly describe Stegomyia fasciata, and state what you know 



about its Habits and Life - History. 



Stegomyia fasciata, the Tiger Mosquito, is the carrier of 

 yellow fever. It is a small domestic species, always found 

 about houses. It is widely distributed throughout Southern 

 Europe, Africa, Asia, and North and South America, and 

 is very common in the West Indies. It is black with con- 

 spicuous white line markings on the body and legs. The 

 lyre-shaped white mark on the thorax is -at once its dis- 

 tinguishing feature. It bites chiefly during the daytime. 

 The black and oval eggs are laid singly or in chains in 

 clean or foul standing water, in puddles, water- barrels, 

 broken bottles, old tin cans, etc. The eggs can resist 

 dry conditions for weeks, for even so long as six months. 



