92 THE ANIMALS AND MAN 



proved that mosquitoes are the conveyers and distributors 

 of the germs of malarial fever (see Chapter XII). Only 

 certain kinds of mosquitoes, however, are malaria-carriers. 

 These all belong to the genus Anopheles; they may be 

 distinguished by the possession of spotted wings, as most of 

 the innocuous kinds have the wings clear. There are a few 

 innocuous or non-malarial kinds with spotted wings, how- 

 ever, but no malaria-carrying kinds with wholly clear wings. 

 The malaria-bearing kinds have the maxillary palpi long in 

 both male and female, while in the other kinds the females 

 have short palpi (fig. 37). Other kinds of mosquitoes are 

 certainly the distributors of the germs of yellow fever, and 

 the same kinds convey a terrible tropical disease called 

 elephantiasis. 



The most effective remedy against mosquitoes is to pour a 

 little kerosene on the surface of the pool in which the larvae 

 and pupae live. The kerosene will spread out and form a 

 thin, oily film over the surface of the water, and no winged 

 mosquito will be able to emerge alive through this film, 

 contact with kerosene being fatal to almost all insects, and 

 and especially so just after a moult. 



For full accounts of the life of mosquitoes see "Mosquitoes," by 

 Dr. L. O. Howard or "Mosquito Life" by Evelyn G. Mitchell. 



CATERPILLARS 



Caterpillars are the larvae of moths and butterflies. While 

 larva is the entomologist's name for the young of any kind 

 of insect that has a complete metamorphosis, most persons 

 call the larvae of different kinds of insects by different names, 

 as grubs for the larvae of beetles, maggots for those of many 

 flies, wrigglers for those of mosquitoes, slugs for those of 

 saw-flies and caterpillars for those of moths and butterflies. 



Most caterpillars are readily distinguishable by the five 

 pairs of short, blunt, fleshy abdominal legs which they 

 possess in addition to the three pairs of jointed thoracic legs. 



