MEMBRANE- WINGED INSECTS. 389 



Aiits do not, as has been so frequently said, lay up stores 

 of corn for the winter, for they are in a state of torpidity during 

 the cold months, and require no food. Moreover, an ant would 

 find as much difficulty in eating or digesting a grain of corn as we 

 should in devouring a truss of straw. 



The Ichneumons form a very large section. They are 

 most-useful to mankind, as one ichneumon will destroy more cater- 

 pillars than a man could kill in his lifetime. They do not, as 

 most other insects, deposit their eggs upon vegetable or dead 

 animal substances, but they actually bore holes in other insects 

 while they are still in the larva state, and leave the eggs to hatch 

 in their living receptacle. The most common ichneumon is a very 

 small insect, not so large as an ordinary gnat. This little creature 

 may be seen searching for caterpillars. It generally selects the 

 common cabbage caterpillar, and sitting upon it, pierces with its 

 sting, or ovipositor as it is called, the skin of the caterpillar, and 

 deposits an egg. After repeating this operation many times, it 

 flies off, arid the caterpillar proceeds as before in the great business 

 of its life, that is, eating, and continues in apparently perfect 

 health until the time for its change into the chrysalis state occurs. 

 The good condition of it, however, is merely deception, for the 

 offspring of the little ichneumon have all this while been silently 

 increasing in size, and feeding on the fat, etc., of the caterpillar, 

 but cautiously avoiding any vital part, so that the plump appear- 

 ance of the caterpillar is merely produced by the young ichneu- 

 mons Mng snugly under the skin. Just as the caterpillar com- 

 mences its change, out come all the ichneumons, looking like little 

 white maggots, and immediately each spins for itself a yellow oval 

 case, frequently enveloping the form of the now emaciated cater- 

 pillar In a few days a little lid on the top of each case is pushed 

 open, and the perfect flies issue forth, and immediately coiumenco 

 their own work of destruction. 



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