12 X. J. Ac.RlCULTURAl. ICx I'lCKI M KNT StATIOX, BULLETIN 348 



Furthermore, a knowledge of the species giving trouble will enable 

 one to trace them to the place in which they breed. 



To obtain this necessary acquaintance with mosquito species, it 

 is essential to become sufficiently familiar with the external anatomy 

 of the larvae and of the mature insects to read and understand the 

 artificial keys used in separating the different kinds. 



In determining the species of mature mosquito caught at a cer- 

 tain point, the locality is of little aid, for many species fly or are 

 wind-carried for long distances. It is necessary to become suf- 

 ficiently familiar with the characteristic marks to determine the spe- 

 cies by its appearance, regardless of the place in which it is found. 



To a certain extent the same thing is true of classifying the larva. 

 The inability of the larva to migrate is offset, to some extent, by the 

 ubiquitous breeding habits of certain species. In general, however, 

 ill woodland pools the woodland species are likely to be found. In 

 swamps the sw^amp species are likely to be prevalent. In reason- 

 ably clear water along the overgrown banks of streams, pools, and 

 small lakes the malarial species are likely to breed. In stagnant 

 pools in the open or about human habitations the house mosquitoes 

 are likely to be prevalent. In the salt-marsh pools the salt-marsh 

 species will be foimd. There is sufficient overlapping of one spe- 

 cies on the territory of another to keep the student constantly on the 

 lookout for the unexpected. 



To sum it up, while the mosquito exterminator can place some re- 

 liance, in determining the species of larva, on the place in which 

 it is found, the safe and satisfactory method is to become sufficiently 

 familiar with the different common species to recognize them at 

 sight. 



Adult or perfect mosquitoes can be successfully classified only 

 when they are killed without crushing. The condition best for de- 

 termination obtains when the specimen has just emerged from the 

 pupal shell and had time (24 hrs.) to harden. From that time for- 

 ward, the markings decrease in clearness through fading and rub- 

 bing until, in specimens that have been on the wing seven or eight 

 weeks, the really characteristic marks disappear, and determination 

 becomes difficult if not impossible. Regardless of the period in 

 adult life when the. mosquito is caught for classification purposes, 

 it should be placed, without touching with the hands, in a cyanide 

 jar or other gas-killing apparatus. As soon as dead it should be 

 emptied on a layer of very loose cotton. Unless it can be pinned 

 within twenty-four hours it should be placed in a relaxing box 



