18 
Journal New York Entomological Sociei\. 
[Vol. v. 
ON THE LARV/E OF CERTAIN SAW-FLIES 
(TENTHREDINID/E.) 
By Harrison G. Dyar, Ph. D. 
Trichiosoma crassum Kirby. 
Mr. MacGillivray has sorted out my bred material into two species 
of Trichiosoma , T. triangulum and T. crassum. There was no corre¬ 
sponding difference in the larvae, however, and, therefore, that of T. 
crassum may be described as being indistinguishable from that of T. 
triangulum. (See Ent. News, vi, 199.) 
Food-plants.—Willow, poplar, wild cherry and alder. 
Hylotoma scapularis King. 
The flies mentioned in Can. Ent., xxvii, 344, under label 2B were 
pronounced by Mr. MacGillivray to be males of this species. The fol¬ 
lowing is the present state of this confusing subject. 
Larvae head black or red. 
No paler subdorsal line. 
Tubercles distinctly black. 
Head red, body yellow ; on birch. 
Head black, rarely reddish, body yellow; on wild cherry.S. 
Tubercles blackish only, or pale in black rings. '* 
Head blue black, body yellow ; on oak. 
A pale yellow subdorsal line. 
Head red or black, body greenish-yellow ; on willow. . 2C 
Head pale testaceous with vertical dark band. 
Body green, tubercles nearly all pale. 
Here are five rather distinct types of larvae. From V have been 
bred H. pectoralis , H. scapularis ? and H. cceruleus $ ; from S has 
been bred H. mcleayi ; from 2B H. scapularis $ \ larvae 2C were bred 
from eggs laid by a female H. clavicorms ; 2L produces H. mcleayi $ 
and H. virescens ( clavicornis ) $ . 
Description of larvae 2B. Four last stages observed with widths of 
head .8, 1.1, 1.8 and 2.5 mm. Head rounded, uniform blue-black, 
the sutures scarcely visible; small black setae in front. Body cylindri¬ 
cal, subventral ridge prominent; thoracic feet large, pale yellowish 
brown, the large basal joint blue-black. Abdominal feet on joints 6 to 
10 and 13 small, the last pair rudimentary, pale at tip, their bases dotted 
with black. Segments coarsely 3-annulated with nine large (.35 mm.) 
setiferous tubercles in an approximate square, the lower posterior one 
moved inward; another behind the spiracle ; these tubercles are black- 
