6 INSSCUTOR INSGITI^ ME^NSTRUUS 



Prospect. At Prospect masamae was scarce, though a few 

 adults were taken. On reaching snow-line, however, they were 

 abundant, and continued so over the snow up to the summit. 

 People living there called them "snow mosquitoes" and were of 

 the opinion that they bred from the snow banks. Larvae were 

 found, however, in small pools along the course of a rivulet 

 issuing from the melting snow, a short distance below the 

 snow-fields. The adults evidently follow the snow upward as 

 it melts, at least the great majority of them, remaining at high 

 altitudes after the snow has gone till late in the season. The 

 dampness of the snow-banks may prove attractive to them. I 

 have not observed such a phenomenon elsewhere. 



The form masamcE is distinguished by the dark brown shade 

 overspreading the mesonotum, although normally colored gray 

 individuals occur. 



Aedes iazarensis tahoensis Dyar. 



Acdes tahoensis Dyar, Ins. Ins. Mens., iv, 82, 1916. 



Acdes tahoensis Dyar, Ins. Ins. Mens., v, 11, 1917. 



Acdes tahoensis Howard, Dyar & Knab, Mosq. No. & Cent. Am. 



& W. I., iv, 1041, 1917. 

 Acdes (Ochlcrotatus) tahoensis Dyar, Ins. Ins. Mens., vi, 78, 



1918. 

 Acdes (Hcteronycha) tahoensis Dyar, Ins. Ins. Mens., viii, 165, 



1920. 



This form inhabits the northern Sierras of California. The 

 adults have the mesonotum gray with slight brown suffusion 

 without great variation. The larvee hatch in large numbers in 

 special large open pools, very early in the season. Tramping 

 over the snow-banks at Summit, California, in April, these 

 pools would be found full of snow and frozen over except at 

 the warmest corner. Here the larvae of tahoensis occurred, 

 well grown, mostly in the last stage, before any of the other 

 species of the region had begun to hatch from the eggs. After 

 the snow is gone, these larvae linger in these large pond-like 

 pools, gradually pupating, drifting about in masses from one 

 side of the pool to another by the wind. These pools occur 

 along the valleys of little streams in their upper reaches, and 

 dry out during the summer. 



