63 
Order HYMENOPTERA. 
This order, as most readers of this report know, includes the 
wasps, bees, ichneumon flies and similar insects. As a very general 
rule, the insects belonging to it are beneficial, but there are some 
exceptions to the rule, as the Saw-flies ( TenthredinicUz ) the Horn- 
tails (Uroceridce) and a family of Gall-makers ( Cynipidce ). The larvae 
of the three families differ very widely in characters and habits, 
those of the first being provided with numerous (in most cases not 
less than eighteen) legs, and, with a few exceptions, feeding openly 
upon the leaves of plants; those of the second possessing six thora¬ 
cic feet, of medium size, and true borers; those of the last family 
are minute, footless grubs and maggot-like, living enclosed in galls. 
TENTHREDINIIhE (Saw-flies.) 
The species of this group are usually known, in the perfect state, 
as Saw-flies, on account of the peculiar boring apparatus with wdiich 
the female is provided, and resemble somewhat closely our wasps, 
but may be distinguished from these by the fact that the division 
between the thorax and abdomen is less distinctly marked, the 
body is more robust and not so slender, the wings are larger in pro¬ 
portion to the body, and the cells more numerous, extending to the 
outer border; the antennae are not elbowed and are rather short and 
simple, clavate or (in a few instances) branched or feathered. 
The larvae very strongly resemble caterpillars, being elongate, 
cylindrical worms provided with six true legs and a number of false 
or pro-legs. But they differ from true caterpillars, as they usually 
have from six to eight pairs of abdominal pro-legs, whereas, the 
caterpillars never have more than five pairs. Many of the species 
curl the posterior part of the body spirally when feeding or at rest. 
They are usually naked, the body being smooth and without hairs, 
though a few have prickles on their backs and some are covered 
with a white, flaky substance. Some of them have a dark slimy 
skin, on which account they are called “slug worms,’’ or “slugs.” 
In addition to their strong resemblance to the true caterpillars in 
form, they also resemble them in habits, being mostly leaf-eaters. 
Some are solitary, others live together in swarms under silken webs; 
some are leaf-rollers, while others make portable cases of bits of 
leaves; a few are found in the stems of plants. 
When fully grown most of them go into the ground, where they 
spin cocoons in which to pass the pupa state and transform into 
the perfect insect; others form strong parchment-like cocoons, which 
they attach to plants or in sheltered places, generally remaining 
over the winter before issuing in the perfect state; though some are 
double-brooded. 
Westwood, in his introduction, arranges the larvae of the family 
Tenthredinidce, as follows, a few of which, the reader will see, do 
not belong to Section I: 
