278 MISSOURI AGRICULTURAL REPORT. 



Usually about the forepart of June these larvae become full grown and 

 then enter the ground, wriggling their bodies until they have packed 

 the earth away and formed a little cell, and then transform to pupae. 

 This pupa stage lasts from two to three weeks. The adults emerge during 

 the latter part of June and the fore part of July. 



The fact that these adults appear so early in the summer has un- 

 doubtedly led many writers to suppose that they now soon lay eggs for 

 a second brood, yet no one has been able to demonstrate the presence of 

 such a brood ; and there are reasons, which I will not .take the time to 

 "discuss, which lead me to believe that the so-called second brood does 

 not occur, at least in Missouri, but that these moths now live until cold 

 weather approaches, and then seek sheltered places under loose bark of 

 trees, under logs and in protected rubbish, and there hibernate during 

 winter, coming out early the next spring in order to deposit their eggs. 

 We have, however, some species of cutworms which are known to be 

 double-brooded. 



r 



NATURAL ENEMIES. 



Both the dingy and the variegated cutworms are preyed upon, some- 

 times greedily, by certain birds. Fowls of all kinds devour them readily ; 

 crows, blackbirds, robins and bluejays are known to feed upon them; 

 certain species of wasps likewise make use of them, and some ground 

 beetles in both the adult and larval stages likewise feed upon them ; but 

 ■ above all, the parasitic insects are the great enemies of the cutworms. 

 Especially is this the case with at least two species of flies belonging to 

 the sub-family Tachininae, and known as Tachinia flies. 



These insects one of which is illustrated in figure 61, persistently lay 

 their eggs upon the bodies of the cutworm larvae ; and the young grubs 

 hatching eat their way through the skin and feed upon the tissues of the 

 larvae, reducing them and weakening them to such an extent that, should 

 they even be able to make pupae, they will never be able to transform 

 to adults. One instance is recorded where cutworms appeared in such 

 immense numbers that they were ruining a clover field, and upon close 

 observation it was found that ninety per cent of these worms were infested 

 with these parasitic flies, and probably not more than one per cent of 

 the larvae in that field ever reached maturity on that account. There 

 are several species of Ichneumon flies that also greatly devastate the 

 ranks of these worms. 



