262 PREDACIOUS AND PARASITIC 



(as in the case of C. lanarius) to say to what family the larva 

 belongs. The carnivorous species, during their earlier existence, 

 are chiefly dependent upon their vegetable hosts for their 

 nutriment ; but after the moult more frequent attacks upon 

 Aphides, and other small insects, may be observed, even in 

 confinement ; and I have noted that, when so kept, recurrence to 

 vegetable juices is much more general than when the insect is in 

 its natural habitat. Some three to four weeks is the apparent 

 duration of the larval condition, and at this time the insect dis- 

 appears from its ordinary haunts, and, hidden in some deep 

 crevice, divests itself of its larval envelope, appearing again with 

 the wing-pads and developments of detail of the nymph or pupa. 

 So well does the insect conceal itself at the time of change that I 

 have never succeeded in finding a cast skin. 



The nymph is much more sturdy (in C. lanarius^ which has 

 been the principal subject of my observations) and rapacious than 

 the larva, and frequently accounts for a considerable number of 

 Aphides — always, I think, in the larval form — in a short space of 

 time. 



A specimen taken in the nymph stage, after a short time, 

 during which it appeared anxious to escape, attacked and consumed 

 three aphis larvse in the course of forty-five minutes. The period 

 of existence in this stage seems very uncertain, and probably 

 depends upon the atmospheric condition and the supply of food. 

 Certainly, a very large proportion of the immature Hemiptera 

 which I have taken from time to time are nymphs. A few days 

 may sometimes see a change to the imago condition, but I have 

 had a Capsid under observation for three weeks, and lost it without 

 any development taking place. 



With the final moult the voracity of the insect becomes much 

 reduced, and it may now be more often found on plants which are 

 not usually frequented by Aphides. The characteristic features 

 also for the first time become clearly defined, and the modification 

 in the number of joints in the antennae, the rostrum, and the tarsi 

 form valuable specific and generic indications. 



The females of the Capsidce and of some other groups which 

 are similarly furnished with an obvious ovipositor are beautiful 

 objects for microscopic study. The eggs are usually laid in rows 



