248 Bulletin 133. 



worms fed for several days on the grass leaves before the autumn 

 frosts forced them to prepare for hibernation. 



The above observations clearly show that at least two broods 

 of army- worms appeared in New York in 1896, one in July and a 

 later one in September. However, across our southern border, 

 in New Jersey, several armies of the worms ravaged crops in 

 May. Although no noticeable injury seems to have been done 

 by the insect last year in New York before July, their appearance 

 in New Jersey in May and our observations on their habits in the 

 fall are quite conclusive evidence that there must have been at 

 least one brood of the caterpillars previous to July in our state. 



We are thus led to conclude that three broods of the army- 

 worm ordinarily occur in New York state. The first brood of the 

 caterpillars are doubtless at work in April and in an " army- worm 

 year' ' may be forced to march in search of new supplies in May 

 in some localities. This May brood of worms transform early in 

 June into the moths which lay the eggs from which hatch the 

 second brood of worms that were so destructive in July last year. 

 Finally, a third brood of caterpillars, the progeny of the moths 

 from the July brood of worms, work in September. 



The most destructive brood. — Usually the second or July brood 

 of the army-worms is the destructive one in New York state and 

 similar latitudes. The first or May brood was noticeably 

 destructive in some localities in New Jersey and Illinois, but seems 

 not to have attracted attention by its injuries in New York. 

 Ninety- five per cent or more of the injury done by the army- 

 worm in New York last year was the work of the second or July 

 brood. In at least two localities, however (Cheviot, Columbia 

 Co., and Warwick, Orange Co.) it was only the September or 

 third brood of the worms which did noticeable damage in 1896. 

 Owing to the activity of their enemies and to other causes, rarely 

 is there more than one i?ijurious brood of the insect during the 

 year, and as stated above, this is usually the second or July brood. 

 Thus in those localities which sufier from the ravages of either 

 the first (May) or the second ( July ) brood of the caterpillars, 

 usually no more armies will be seen during the rest of the season. 

 This is a very important phase of the question for upon it may 

 depend the answer to the question so often asked in July last 



