420 INSECTS. 



SECTION XII. 



Ichneumon, 



Ichneumon. Linh. 



The animals of this genus provide for the support of their off- 

 spring in a manner highly extraordinary ; depositing their eggs in 

 the bodies of other insects, and generally in those of caterpillars. 

 For this purpose the female ichneumon, selecting her victim, and 

 fastening upon it, pierces its skin with her abdominal tube, and 

 introduces her eggs beneath the surface. In vain the tormented 

 animal endeavours to evade this cruel operation : the ichneumon 

 maintains her hold, nor ceases till she has discharged her whole 

 stock. These eggs in a few days hatch, and the young larves, 

 which resemble minute white maggots, nourish themselves with the 

 juices of the unfortunate animal, which however continues to move 

 about and feed till near the time of its change to chrysalis ; when 

 the young brood of Ichneumon-larvae creep out, by perforating the 

 skin in various places, and each spiuning itself up in a small oval 

 silken case, changes into chrysalis; the whole number forming a 

 groupe on the shrivelled body of the caterpillar which had afforded 

 them nourishment; and, after a certain period, emerge in the 

 state of complete Ichneumons. One of the most familiar examples 

 of this process, is afforded by the well-known caterpillar of the 

 common white or cabbage butterfly ; which, in the autumnal sea- 

 son, may be frequently observed to creep up some wall, or other 

 convenient surface, in order to undergo its own change into chry- 

 salis ; but, in the space of a day or two, a numerous tribe of small 

 maggots will be seen to emerge from it, and immediately proceed 

 to envelop themselves in distinct yellow silken cases ; the whole 

 forming a groupe around the caterpillar. The ichneumons pro- 

 ceeding from these are the species called by Linnaeus ichneumon 

 gloraeratus : their colour is black, with yellow legs : they usually 

 make their appearance in about three weeks from the time of their 

 spinning themselves up. Other small species of Ichneumon pierce 

 the skins of newly changed chrysalites of butterflies and moths, in 

 which their larves remain during their own incomplete state; as the 

 ichneumon puparum of Linnaeus, a very small species, of a girded 



