742 MOSQUITOES OF NORTH AMERICA 



somewhat swollen ; vestiture deep bronzy brown ; long hairs on end of long joint 

 and the last two joints long and abundant, deep brown with a pale reflection in 

 certain lights. Antennae plumose, the last two joints long and slender, pilose, 

 the others shorter, blackish ; hairs of whorls long dense, brownish black. Color- 

 ation similar to the female. Abdomen elongate, depressed ; dorsal white bands 

 broader than iu the female; lateral ciliation dense, fine, pale yellow. Wings 

 narrower than in the female, stems of the fork-cells longer, but still shorter 

 than their cells ; vestiture less abundant. Posterior tibise with a fringe of rather 

 long dense hairs. Claw formula, 3.1-3.1-1.1. 



Length : Body about 5 mm. ; wiag 4 mm. 



Genitalia (plate 27, fig. 183) : Side-pieces more than twice aB long as wide; 

 apical lobe well developed, prominent, continued broadly along side-piece to 

 basal lobe, which is conically prominent and bears numerous setae, a stout 

 hooked spine with an attendant group of smaller spines. Clasp-filament slender, 

 moderate, slightly expanded in middle, notched towards apex and bearing a few 

 fine Betas, a long articulated terminal spine. Harpagones with a stout, thick, 

 nearly straight columnar base with two small setse on inner side, bearing an 

 articulated terminal filament, short and widened in the middle. Harpes ellipti- 

 cal, concave, curved, inner margin thickened and revolute, tip pointed and curved 

 outward. Unci approximate, revolute, forming a large basal cone. Basal 

 appendages remote, bearing four or five stout terminal setse. 



Larva, Stage IV (plate 120, fig. 413). — Head rounded, widest through eyes; 

 antennffi rather small, uniform, minutely spinulated; hair-tuft small, situated 

 before middle ; both pairs of dorsal head-hairs single, ante-antennal tufts in fives. 

 Lateral abdominal hairs in twos on second to sixth segments. Tracheal tubes 

 broad. Lateral comb of eighth segment of about twenty-five scales in a patch, 

 the single scale shortly fringed laterally, with a long sharp apex, as long as 

 body of scale. Air-tube rather less than three times as long as wide, slightly 

 tapering outwardly ; pecten of evenly spaced teeth reaching slightly beyond mid- 

 dle of tube, followed by a single small tuft of about five hairs. Anal segment 

 longer than wide, with a large dorsal plate that reaches to near the ventral line ; 

 dorsal tuft a long hair and tuft on each side ; ventral brush vsdth small tufts pre- 

 ceding the barred area; anal gills long, tapering, pointed, equal. 



The adults flew later in the season than those of Aedes puMatus and showed 

 more of a tendency to enter the house. The larvis were obtained the next season 

 from eggs laid by captured females, so that it is probable that there is but a 

 single annual generation with hibernation in the egg state, the larvas breeding 

 in the early spring pools, but perhaps not emerging so early. They were not 

 found in nature. Dr. Dyar says : 



"This species appeared rather late in the season, no examples being seen 

 till the end of June, after which it became fairly abundant. The flies were per- 

 sistent in their attacks, alighting and biting at once, without the preliminary 



deliberations seen in other species This is the summer mosquito of the 



Kootenays and lasted longer than any other of the single-brooded species. Eggs 

 were obtained of the usual spindle shape, rather thick and unusually small, laid 

 singly. They have hibernated." 



Northern Rocky Mountains, in Canada. 



Kaslo, British Columbia, end of June to August, 1903 (H. G. Dyar) ; 

 Nanoose Bay, Vancouver Island, British Columbia, August 1, 1903 (J. 

 Fletcher). 



Aedes cestivalis has no doubt a wider distribution than indicated by our 

 localities. It is impossible to determine accurately species in this group from 

 captured females in indifferent condition such as usually received. We have 

 therefore omitted doubtful records, but consider it safe to refer here the speci- 



