HYAfENOPTERA. 417 



FAMILY I. 



SECURIFERA* 



OUR. first family is distinguished from the following ones by a sessile 

 abdomen, or the base of which is joined to the thorax throughout its whole 

 thickness, that seems to be a continuation of it, and to have no separate 

 motion. 



The females are provided with an ovipositor that is most commonly 

 serrated, and which not only enables them to deposit their eggs, but likewise 

 to prepare a place for their reception. The larvae always have six squamous 

 feet, and frequently others that are membranous. 



This family is composed of two tribes. 



In the first, that of the TENTHREDINET^E, vulgarly termed Saw-Jlies, we 

 observe elongated and compressed mandibles; a trifid or sort of digitated 

 ligula; an ovipositor formed of two serrated, pointed blades, united and lodged 

 in a groove under the anus. The maxillary palpi are all composed of six 

 joints, and the labials of four ; the latter are always the shortest. The wings 

 are always divided into numerous cells. This tribe forms the genus 



TKNTHREDO, Linnaeus, 



The cylindrical abdomen of these insects which is rounded posteriorly, 

 composed of nine annuli, and so closely joined to the thorax that the two seem 

 to be continuous; the ragged appearance of their wings ; the two little rounded, 

 granular, and usually coloured bodies situated behind the scutellum, together 

 with their heavy port, cause them to be easily recognised. The abdomen of 

 the female presents at its inferior extremity a double, moveable, squamous 

 ovipositor that is serrated, pointed, and lodged between two concave laminae, 

 forming its sheath or case. 



It is by the alternate action of the teeth of this ovipositor, that the insect 

 makes a number of little holes in the branches, and various other parts of trees 

 and plants, in each of which it first deposits an egg, and then a foaming liquid, 

 the use of which, it is presumed, is to prevent the aperture from closing. The 

 wounds made in this way become more and more convex by the increasing 

 size of the egg. Sometimes these excrescences assume the form of a nut-gall, 

 either ligneous or soft and pulpy, or resemble a little fruit, according to the 

 nature of the parts of the plants that are affected by them. These tumours 

 then form the domicile of the larva? which inhabit them either solitarily or in 

 societies. There they undergo their metamorphosis, and issue from them 



* Hatchet bearers. 

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