MAY FLIES AND MIDGES OF NEW YORK 



1T7 



Male. Thorax cinereous^ with three cinereous black stripes, 

 the two laterals anteriorly abbreviated, the interval between 

 sparsely hairy, scutelluni cinereous brown, pilose, inetathorax 

 cinereous-black, the pleura gray, the pectus cinereous-black. 

 Abdomen slender, cinereous-black with yellow hairs, the venter 

 paler, the anal segments wide. Antennae brown, 14-jointed, 

 plumose. Legs more or less dull brown, slender, setose. Halteres 

 white. Wings slightly tinted, nearly hyaline, the margin short 

 ciliate, the venation like that of D. aberrata. The fourth 

 tarsal joints shorter, or at least not longer than the fifth ; the fore 

 metatarsus is somewhat shorter than the tibia. 



Female. Antennae 8-jointed, short, the last joint elongate, 

 fusiform, the abdomen shorter and stouter than that of the male; 

 differs from the female of D . aberrata in its smaller size, 

 shorter antennae, and wholly cinereous abdomen. Length of male 

 and female 2.7.5 to 4.25 mm. Greenland. Translation. 



3. Diamesa culicoides Heeger 

 1853 Sitzb. K. K. Acad. Wiss. Wien. 10:7 



The larva, pupa and adult of this European species were de- 

 scribed by Heeger (1853). Heeger's figures are reproduced on 

 pl.36, fig. 15 to 25. 



According to this author 80 to 100 eggs are laid by the female 

 in groups of 10 or 12 upon stones or other objects along banks of 

 the brook where they may be washed by the water from time to 

 time. The eggs are described as being yellowish-white, nearly 

 cylindrical, slightly smaller at one end, scarcely .25 mm. in length 

 and nearly one-half as wide. The larvae emerge in about 8 or 

 10 days. They are white in the beginning; later the dorsal sur- 

 face becomes brownish. When full grown about 12 mm. in 

 length. The eyes are subtriangular, small, fiat and black; the 

 labrum is rounded, brownish-yellow, chitinous, scarcely one- 

 sixth as broad as the head, one-half as long as broad, with four 

 rounded teeth. The loAver lip is one-half as broad but twice as 

 long as the labrum, pale yellowish, truncated anteriorly, with the 

 anterior margin densely hairy; the palpi are attached basally 

 to this, and have the same structure as the lower lip. The labium 

 is dark brown, is one-fourth as broad as the head, with a semi- 

 circular anterior margin, this margin provided with six very short 

 rounded teeth on each side, and in the middle with a broadly 

 truncated one (fig.19) ; the mandible (fig.l8) is subcordate, one- 

 fourth as long as the head, with five short rounded teeth, proximad 

 of which there is a long row of yellowish brown, movable setae. 

 The larva spins a thin, tube-like dwelling from which the head 



