The Mosquitoes of New Jersey ii 



the lower lip of the chewing insect. It is grooved lengthwise along 

 its upper surface and forms a trough in which the delicate piercing 

 lancets lie and by which they are protected from harm. 



The lancets consist of six parts. The upper is a compound struc- 

 ture representing the labrum, or upper lip, and the epipharynx of the 

 chewing insect. The epipharynx is grooved lengthwise of its lower 

 surface in such a fashion as to form a complete tube when the 

 hypopharynx is laid against it from below. The hypopharynx is a 

 slender, flattened piece that fits closely against the open groove of the 

 epipharynx. Through the tube thus formed the victim's blood is 

 drawn into the mosquito's digestive tract. The next pair of lancets 

 are slender, sharp pointed rods which correspond to the mandibles, 

 or primary jaws, of chewing insects. The next pair of lancets, 

 which correspond to the maxillae, or secondary jaws, of chewing in- 

 sects, are also slender and pointed, but have slightly enlarged barbed 

 ends. Almost if not quite coincidently with the moment that the 

 skin is pierced, a small amount of saliva is injected through the 

 epipharyngeal groove into the wound and suction begins very soon 

 after that. The pumping portion, the foreintestine, regularly con- 

 tracts and expands, drawing the blood from the victim into the mos- 

 quito's body. Unless disturbed, the creature will continue to feed 

 until its abdomen is distended almost to bursting. 



According to the late Dr. Smith, the mosquito requires about 

 three minutes to complete its meal and then flies away to rest in 

 some convenient spot until the blood is digested. 



Structure and Classification 



Speaking from the standpoint of mosquito suppression, it would 

 be difficult to overestimate the value of a knowledge of mosquito 

 species. Not only are the methods to be employed determined di- 

 rectly by the habits of the specific species, which are troublesome, 

 but a true estimate of the results of the work cannot be reached 

 without this knowledge. If the troublesome mosquitoes in a given 

 locality are really salt-marsh species, a knowledge of that fact 

 would prevent the useless expenditure of time and money on control 

 of local breeding. If, in spite of all work which a municipality can 

 do, it is overrun with mosquitoes, a knowledge of the species con- 

 cerned will enable one to determine whether their presence means 

 the failure of local work to control breeding or whether the munici- 

 pality has a visitation of mosquitoes bred outside its boundaries. 



