492 MOSQtriTOES of north AMERICA 



/ 

 large, pointed. Both pairs of dorsal head-tufts and ante-antennal tufts multiple. 

 Mental plate elongate triangular, with a central tooth and thirteen on each side, 

 basal ones larger and more remote, last one small. Mandible quadrangular, 

 elongate, part beyond collar especially prominent ; two stout and two slender fila- 

 ments before collar; a row of cilia; twenty filaments on outer margin in a double 

 row, outer ones short, all bluntly tipped ; dentition of five teeth on a process, the 

 second one the longest, two rounded teeth before, three at base, a broad, serrate 

 filament within; process below short, rather widely furcate, with hairs out- 

 wardly; basal angle blimt, a group of hairs within; a row of long hairs at base. 

 Maxilla hemispherical, divided by a suture which runs inwardly, the inner part 

 being parallel to base; inner half hairy toward margin, with a group of small 

 hairs near angle of suture, two hair-tufts at tip ; outer half sparsely haired with- 

 out, two stout separate filaments situated near suture subapically. Palpus 

 small, with four curved apical digits. Thorax roimded, wider than long, robust ; 

 hairs abundant, the single hairs rather long, prothoracic tufts multiple and 

 nearly as long as head. Abdomen stout, the anterior segments short; hairs 

 rather short, lateral hairs multiple to fifth segment, double on sixth, single on 

 seventh, confused by subdorsal and subventral tufts, which are rather long on 

 third to sixth segments. Tracheal tubes moderate, not band-shaped, flexuous 

 posteriorly. Air-tube stout, tapered outwardly, two and a half times as long as 

 wide ; pecten of small teeth at base, becoming long hairs beyond basal third and 

 running to apical fourth; single spine with three basal branches, except in the 

 case of the outer hair-like spines ; a large tuft close to base, almost at base of 

 pecten. Lateral comb of eighth segment of many spines in a triangular patch ; 

 single spine with a round, blunt basal production, apical part long and widened 

 a little outwardly, evenly fringed with long spinules. Anal segment about as 

 long as broad, ringed by the plate ; dorsal tuft a group of three hairs and brush 

 on either side; a two-haired lateral tuft; ventral brush well developed, with 

 small tufts preceding nearly to base. Anal gills small, shorter than the seg- 

 ment, tips abruptly pointed. 



The eggs (plate 147, figs. 691 and 693) are laid in large boat-shaped masses, 

 floating on the water and usually at the margin of the pool, where they are 

 drawn by capillary action. They hatch within a few days. There are four larval 

 stages, as usual. Several broods occur during the season, the females finally 

 going into hibernation. The larvae are inhabitants of permanent water, pools in 

 stream beds or spring holes being the natural breeding-places. The species 

 shows but slight tendency to domestication, being mainly confined to their 

 original wild breeding-places except in certain instances, such as occur at Kla- 

 math Falls, Oregon, where a part of the lake had been cut off by banks of mud 

 and refuse from the saw mills. Dr. Dyar found larvae in old abandoned well- 

 holes dug near the shore of a large marshy pond at Laguna, California (near 

 Los Angeles). This is perhaps the beginning of a trend toward domestica- 

 tion. They generally occur in dark pools in stream-beds when the streams 

 have gone partly dry. The water in these places is occasionally somewhat foul, 

 but not so to a great degree. The adult females are not troublesome, being 

 usually rare and not aggressive. They do not enter houses. The adults appear 

 not to swarm for mating, certainly not to any marked extent. Copulation lasts 

 for a considerable time. Dr. Dyar observed several pairs in copulation, resting 

 on the under sides of some boards which were placed over water. The pairs 

 remained united when the boards were overturned, and were captured in a 

 cyanide bottle. They did not separate even in the bottle, though they became 

 separated before the bottle was emptied. Both sexes of the pairs were standing 

 on the board, facing in opposite directions. 



