HYMENOPTERA. 583 



others, but which are membranous. This faniil)' is composed of two tribes, [the Tenthredineta; and 

 Urocerata] . 



The Tenth REDiNET.i: — , 

 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 antenna; varies ; the mandibles 

 are strong and toothed ; the maxillai7 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, but 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 tibice, 

 have the ovipositor not exserted, the labrura 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 lan'ae 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. 



'^' fLciata, Leauh)! Perga, Lcach, (one of these genera), peculiar to New Holland, diflers from the 



rest by having the four posterior tibia; furnished with a moveable spine in the middle, the posterior angles of the 



scutellum produced into short obtuse teeth, the antenna; very short and 6-jointed. 



Syzygonia, Klug, 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 Tenthredinidue, adopts only the genus Perga, and we also consider the genera 

 of Leach as simple divisions in the genus Chnbex, the type of which is the Tenthredo femorata, [a large and rare 

 British species]. 



llylotoma, 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 larvee 

 have from eighteen to twenty feet. Type, Tenthredo Rosa, Linn., [a common British species]. 

 i<chizocerus, Latr. (Cryptus, Leach), has four subniarginal cells, and the male antenna; forked. 

 PtUla, St. Farg., differs from Hylotoma in having only three subniarginal cells. Sometimes the antenna; have 

 at least nine joints, and do not terminate in a mass. 



Tenthredo proper, have nine simple joints in both sexes ; the lar\a; 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 Allantii.i, Dolerus, Nemaius, Jur., and Pristiphora and 

 some others of Leach, [such as tielandrin, Feiiusa, Dosythcus, Emphytus and Crwsiis]. Type, T. Scrophularia, 

 Linn., a common species, much resembling a Wasp, the larva of which feeds on the Water Betony. Ue Geer has 

 described a singular species, which in the larva state infests the leaves of our fruit trees under the form of a small 

 bUok slug, and to which he refers the Tenthredo Cerasi, Linn. ; this larva is black, and covered with a sliniv 

 serveiion. Peck, an American naturalist, has given the complete history of another species, which has a 

 siuiiliir larva. 



