76 THE MOSQUITOES OF NEW JERSEY 



ties. It seems, however, to move as an individual rather than in consider- 

 able bodies and the increase in numbers is gradual ; there is no sudden 

 appearance of a swarm overnight. So the disappearance is equally 

 gradual, isolated specimens remaining in town until early October and 

 in the field much later. 



The adults die off gradually as winter advances and hibernation is in 

 the egg stage. The eggs are deposited singly on the surface of the water 

 and sink to the bottom, or they may be placed at the edge of a low pool 

 or in the moist mud of a depression from which the water has evapo- 

 rated. The length of adult life is probably considerable, but no definite 

 experiments were made and the period of nearly three months is based 

 upon field observations only. At all events it is not a brief one and is 

 reckoned by weeks rather than days. 



DESCRIPTION OF THE LARVA 



Larva varies greatly in size, measuring from 6-8.5 mm. (.24-.34 

 inch), exclusive of anal siphon. Figures opposite drawn from large 

 sized larva. Full grown specimens yellowish or grayish throughout, but 

 when young almost white, except head, which is yellow. Head is broad- 

 est immediately below eyes, tapers anteriorly and is rounded in front. 

 Six small hair tufts of four or five hairs each on anterior of vertex ; one 

 at base of each antenna, others more central, one pair to rear of other. 

 Maculation of head varies immensely, though always symmetrical; 

 Fig. XXV shows some of forms, all common and may be present in a 

 single lot. By far the commonest form, however, is that shown in the 

 Fig. XXV ; defined brown patch in center of anterior part of vertex 

 and another smaller in center or posterior part of vertex, on a yellow 

 ground color. Entire lots often have this form of maculation ; as there 

 are no other species with similar markings, it usually identifies larva. 

 In young and half grown larvae heads wholly pale yellow, save for 

 slight mark in center. Antenna rather short, curved, thickest at base, 

 tapering apically ; surface set with stout spines, color yellow, becoming 

 darker toward apex. The apex has one long and one short spine, two 

 bristles and a small joint. Tuft situated on shaft one-third from base; 

 consists of six or eight hairs. Rotary mouth brushes dense, orange col- 

 ored, have hairs pectinated in more central part. Mentum triangular, 

 with from twelve to fourteen small teeth on each side of apex. Mandible 

 and maxillary palpus normal, latter with stout basal joint not shown 

 in drawing. 



Thorax broader than long, angulated at sides, with rather small- 

 sized tufts arising from angles. 



