THE IXSECT WORLD. 



295 



FiCx. ,^33. 



The armv-worm. 



large that they make havoc where they hatrh. In this stage they 

 are noticed in wheat where it is heaviest, and thence the cater- 

 pillars spread in every direction. They soon become full-grown, 

 go a short distance underground to change 

 to mahogany-brown pupae about three-fourths 

 of an inch in length, and shortly thereafter 

 the moths appear. They mate at once and 

 lay another batch of eggs, from which we 

 have about midsummer a second army much 

 larger than the first. These soon eat every- 

 thing on the ground first occupied by them, 

 and are then forced by hunger to begin those 

 marches which have given them their com- 

 mon name, "army-worm." It is an inter- 

 esting, though to a former not a pleasant, 

 sight to see the march of these insects from 

 a stripped field to one that is still green and 

 flourishing, and to note how quickly every- 

 thing becomes covered and disappears, a sin- 

 gle day sufficing to clear a large plot of every trace of vegetation. 

 When full-grown these larvae in turn go underground, and now 

 there is a divergence in development. Some of the pupae remain 

 unchanged all winter ; some of them produce moths, and of 

 these some will go into winter-quarters and hibernate, while 

 others mate and lay eggs for a late brood of caterpillars, which 

 becomes only partially grown. The insects may, therefore, 

 winter in either the larval, pupal, or adult condition, though it is 

 probable that the pupa stands the best chance of surviving. At 

 all events, this explains how it is that caterpillars of all sizes may 

 be found at all times, and that during the entire season moths 

 may be found. In my own experience, there has not been a 

 week in the collecting year when I have not taken this insect, 

 while seeking better species. The remedies to be adopted are 

 almost entirely mechanical. Where the larvae are noticed at the 

 first start in grain-fields or grass lands, the patches infested by 

 them should be at once cut down and utterly destroyed by 

 fire, and with them, of course, the larvae. The work must be 

 done thoroughly, because otherwise the caterpillars will simply 

 crawl to adjacent plots, and the labor is wasted. The thorough 



