74 CULICID^ [CH. 



found amongst the family Culicidse itself. The predaceous 

 and cannibalistic larvae of Psorophora, Lutzia, Megarhinus, etc., 

 readily attack larva either of their own, or other species. The 

 larva of Lutzia is so effective that in Rio de Janeiro it has been 

 employed to destroy the larvje of the more dangerous Stegomyia 

 fasciata. The immature stages of many other aquatic Diptera 

 also prey on the Culicidse. 



Various predaceous Diptera, especiallythe Empidida, capture 

 mosquitoes along with other insects ; a blood-sucking fly, Simu- 

 lium, has been observed to kill mosquitoes by sucking the blood 

 out of them. A most curious case, however, is that of an 

 Anthomyid fly, Lispa sinensis, which has been seen to catch 

 and eat the larvae of mosquitoes in Hongkong. A Dolicho- 

 podid fly of Panama also attacks the larvae in a similar manner. 



Mites have frequently been seen attached to the bodies of 

 both the adult and immature stages of mosquitoes. In some 

 regions, e.g. Uganda, as many as 50 per cent, of the mosquitoes 

 may be attacked. The presence of these mites, however, does 

 not seem to affect seriously the health of the host, though no 

 doubt it may be weakened. Spiders undoubtedly destroy 

 large numbers of mosquitoes, and are amongst the most efficient 

 natural enemies of the adult insects. The jumping spiders 

 of the genus Salticus are very common in houses in the tropics, 

 and are a most valuable aid in the destruction of both mos- 

 quitoes and flies. 



Newts and the aquatic larvae of salamanders readily devour 

 mosquito larvae, and the latter are rarely found in pools 

 inhabited by these batrachians. 



In India the common gecko lizard destroys large numbers 

 of Culicidje in houses, and therefore should be encouraged 

 as it is quite harmless. 



Birds and bats, however, must be regarded as the most 

 important vertebrate enemies of the adult mosquitoes. The 

 smaller insectivorous birds, night-hawks, swifts and swaUows, 

 all devour enormous numbers of Diptera. More than 600 

 insects, mostly mosquitoes, have been counted from the stomach 

 of an American swift {Chcshtra pelagica). In addition aquatic 

 and shore-birds eat considerable numbers of the larvae. At 



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