HYMENOPTERA. 
583 
others, but which are membranous. This family is composed of two tribes, [the Tenthredinetce and 
Urocerata]. 
The Tenthkedinet^ — , 
Or Saw-flies [as they are commonly called, from their saw-like ovipositor], have the mandibles long and 
compressed, the lower lip divided into three lobes, the ovipositor composed of two plates, toothed like 
a saw, united, and lodged in a channel beneath the anus ; the maxillary palpi are always composed of 
six joints, and the labial of four ; the wings are always divided into numerous cells. This tribe is 
composed of the genus 
Tenthredo, Linn. 
The abdomen is cylindric, rounded behind, 9-jointed ; the form of the antennae varies ; the mandibles 
are strong and toothed ; the maxillary palpi are filiform and 6-jointed ; the lower lip is divided at the apex 
into three lobes ; the labial palpi are only 4-jointed. It is with the alternate motion of the saws of the 
ovipositor that these insects make a succession of small holes in the branches or other parts of trees, 
in each of which an egg and a drop of frothy liquid are discharged, the latter of which has the effect of 
closing the hole. The wound thus made becomes more and more convex by the increase in size of the 
egg, and sometimes these parts assume the form of a gall, either woody or pulpy, according to the parts 
injured ; these tumours form the abode of the larvae which reside within them, and the insect makes 
with its teeth a circular hole for its escape. But in general these larvae are external feeders, devouring 
the leaves. They greatly resemble the Caterpillars of Lepidopterous insects, hut have from eighteen 
to twenty-two feet, or only six, which distinguishes them from caterpillars, which have from ten to 
sixteen feet. Many of these false caterpillars roll themselves into a spire, and others have the 
extremity of the body elevated in the air. In order to undergo their change, they spin, either on the 
earth or on the plants upon which they have fed, a cocoon, in which they remain unchanged for many 
months, changing to pupae only a few days before they become perfect Sawflies. 
Some, in many of which the antennae are not more than nine-jointed, with two spurs at the tip of the fore tibiae, 
have the ovipositor not exserted, the labrum apparent, the inside of the four hind tibiae without spines in the 
middle, or with only one ; the larvae have from twelve to sixteen false legs. 
Cimbex, Oliv. {Crabro, Geoffr.), comprises those species which have the antennae 
alike in both sexes, and terminated by a knob or a reversed cone rounded at the 
tip, preceded by four or five joints, and the two subcostal nerves are contiguous 
without a wide intermediate space. The larvae have 22 feet ; some when disturbed 
discharge from pores of the body, often to the distance of a foot, drops of a 
greenish liquid. Dr. Leach has divided this genus into numerous others [adopted 
by English authors], founded upon the number of joints in the antennae preceding 
the club, their relative sizes, and the arrangement of the cells of the wings. 
Fig. (ZarBea Leach, (one of these genera), peculiar to New Holland, differs from the 
rest by having the four posterior tibiae furnished with a moveable spine in the middle, the posterior angles of the 
scutellum produced into short obtuse teeth, the antennae very short and 6-jointed. 
Syzygonia, King, has also 6-jointed antennae, and the radial cell is appendiculated. The species are Brazilian, 
as well as those of Pachylosticta, Klug, which have antennae composed of five joints, and the fore-wings dilated 
near the apex. 
Saint Fargeau, in his work on the Tenthredinid<s, adopts only the genus Perga, and we also consider the genera 
of Leach as simple divisions in the genus Cimbex, the type of which is the Tenthredo femorata, [a large and rare 
British species]. 
Hylotoma, Latr. (Cryptus, Jur.), has the antennae apparently only 3-jointed, the third forming a long prismatic 
or cylindric mass ; the greater number have a spine on the inside of the four hind tarsi, in the middle. The larvae 
have from eighteen to twenty feet. Type, Tenthredo Roste, Linn., [a common British species]. 
Schizocerus, Latr. {Cryptus, Leach), has four submarginal cells, and the male antennae forked. 
Ptilia, St. Farg., differs from Hylotoma in having only three submarginal cells. Sometimes the antennae have 
at least nine joints, and do not terminate in a mass. 
Tenthredo proper, have nine simple joints in both sexes ; the larvae have from 18 to 22 feet. The number of teeth 
in the mandibles varies in the perfect insect from two to four ; the wings also vary in the number of the cells, and 
hence various subgenera have been established, such as Allantus, Dolerus, Nematus, Jur., and Pristiphora and 
some others of Leach, [such as ^elandria, Fenusa, Dosytheus, Emphytus and Crcesus], Type, T. Scroplmlarice, 
Linn., a common species, much resembling a Wasp, the larva of which feeds on the Water Betony. De Geer has 
described a singular species, which in the larva state infests the leaves of our fruit trees under the form of a small 
black slug, and to which he refers the Tenthredo Cerasi, Linn. ; this larva is black, and covered with a slimy 
secretion. Peck, an American naturalist, has given the complete history of another species, which has a 
similar larva. 
