HYMENOPTEROUS IXSECTS. 



OF THE CYNIPS, OR GALL-INSECT TRIBE. 



THE insects of the Linnean order Hymenoptera have generally four 

 membranaceous, naked wings. In some of the tribes the neuters, and 

 in others, the males or females, are destitute of wings. The tail, in the 

 females and neuters, is armed with a sting. 



The mouth is furnished with a short, single-toothed, membranaceous 

 jaw. The mandibles are horny and cleft, and the lip is entire. The 

 feelers are four in number. The sting is spiral, and often concealed 

 within the body. 



Most of the Gall-insects are produced from eggs deposited by tho 

 parents in the tender branches, or upon the leaves of trees in the 

 spring of the year; others live concealed among the leaves, and others 

 are bred in the bodies of other insects. 



Those which deposit their eggs in the branches or leaves of trees, 

 place them in a small hollow, which they form by means of an 

 instrument at the posterior part of their body. Each egg is fixed to 

 the spot by a kind of gluey matter, with which it is covered. 



The juices of the leaf or stem overflow by the small vessels, which 

 are opened in this operation, and thus form a gall or excrescence, in 

 which the egg becomes enclosed. When the larva is hatched, it finds 

 around it the food, that is necessary for its subsistence. It gnaws and 

 lives upon the substance of the gall, which increases in bulk and con- 

 sistence, in proportion as its interior is thus destroyed. 



Some of these galls have, in their interior, either only one cavity, 

 in which many larvae are enclosed together, or many small cavities, 

 having a communication with each other; some have many separate 

 cavities; and others have only one cavity, which is occupied by a 

 solitary insect. 



When the larvae have attained their full growth, some of the species 

 eat their way out, and drop upon the earth, in which they bury 

 themselves, and there undergo their metamorphosis; and others are 

 transformed within the galls, and leave them only as perfect insects. 



OF THE TENTHREDO, OR SAW-FLY TRIBE. 



THE mouth has a horny curved mandible, toothed within. The jaw 

 is straight and obtuse at the tip, and the lip is cylindrical and bifid. 

 The feelers are four in number, and filiform. The wings are tumid, 



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