65 



content herself with merely attaching the eggs to the plants in the same way as insects 

 which are not equipped for carpentering. 



From the eggs so carefully and laboriously deposited there hatch elongated, cylin- 

 drical larvae, often resembling very closely those of lepidoptera, and for that reason known 

 as "false-caterpillars." There are, however, structural differences by which they may 

 be readily distinguished from the larvae of moths and butterflies. The most noticeable of 

 these is the relative number of abdominal or prolegs. No caterpillar has more than five 

 pairs of these, whereas the saw-fly worms have from six to eight pairs, except in the 

 peculiar genus Lyda, the larva? of which are destitute of them. 



The habits of saw-fly larvae also resemble those of the true caterpillars — many spe- 

 cies feed openly upon the foliage of plants, in large family groups, or singly, while others 

 seclude themselves in galls, produced either by themselves or by other species of insects. 

 When fully grown, the majority of species spin a silken cocoon, of greater or less com- 

 pactness, within which to pupate. This cocoon is at times affixed to the food plant or to 

 adjacent objects, but is more commonly found beneath the leaves and rubbish on the 

 ground, or buried at varying depths beneath its surface. Many species do not spin a 

 cocoon, but instead burrow in the ground and construct earthen cells in which to undergo 

 the customary transformations. The duration of the several stages of life naturally 

 varies with different genera and species : some are only single-brooded, while others pro- 

 duce two, three or more broods annually, and thus multiply so rapidly as to become, under 

 favourable conditions, exceedingly abundant and destructive. 



Having thus, rapidly and imperfectly, outlined the appearance and habits of the 

 insects belonging to the family Tenth redinidae, I will proceed to consider the several groups 

 into which, for convenience of study, it is divided, and will give brief descriptions and 

 life-histories of some of the better-known species. Although the family has been but 

 meagrely studied in Canada, the species are so numerous that fully two hundred are 

 recorded. The record is, however, as regards a large proportion of them, unfortunately 

 confined to the mere capture of specimens, and an immense amount of work must yet be 

 done before the complete life-history of each species can be given, while many additional 

 species, doubtless, remain to be discovered. 



Sub-families, six in number, have been formed, which are characterized chiefly by 

 the number of articulations, or joints, of the antennae. These are again divided into 

 groups according to the number of marginal and sub-marginal cells, while minor differ- 

 ences of structure are made use of in distinguishing the genera which compose the res- 

 pective groups. 



Sub-Family 1. — Cimbicin^e. 



The species included herein have short club-shaped antennae consisting of from five 

 to eight segments, and include our largest and most formidable representatives of the 

 Tenthredinidae. Of these the list is headed by Cimbex americana, which varies in length 

 from three-fourths of an inch to one inch, and from one and three-fourth to two and one- 

 fourth inches in the expanse of its wings. The sexes differ greatly in appearance, the 

 male having the abdomen more elongated and flatter beneath. His legs, especially the 

 four posterior ones, are enormously developed, and, with his long, toothed mandibles, 

 maiie him a ferocious looking insect, as with strong, noisy flight he circles about in search 

 of his mate. There are several distinct varieties of this species, separated by the colour 

 and markings of the abdomen, and the relative clearness of the wings. The clear-winged 

 varieties prevail in Canada ; but even in these the margin of the wing is cloudy, as is 

 also a spot beneath the stigma. In the typical form of the species the male is black, the 

 head and thorax having a bluish, and the abdomen a purplish tinge. The female is black 

 with a yellowish spot on the sides of the third, fourth and fifth segments of the abdomen. 

 Both bexes have yellow feet and antennae, the latter having seven joints, the last three 

 forming a knob. The larva feeds chiefly upon the elm, but frequents also other trees, as 

 willow and linden. It is of a pale yellowish colour, with a black stripe running down 

 the back, and black dots along the sides. It is solitary in its habits, and when at rest 

 upon a leaf, is coiled up like a snail-shell. When disturbed, it discharges a fluid secretion 



5 (EN.) 



