INSECTS AFFECTING GRAINS, GRASSES, ETC. 



113 



broods a year, the young larvae usually hibernating, while in the 

 South there may be as many as six generations, and the 

 moths usually hibernate over winter and lay their eggs in the 

 spring. 



The moths very often fly into lights and are among the com- 

 monest of our plain " millers." The front wings are a clay or 

 fawn color, specked with black scales, marked with a darker 

 shade or stripe at the tips, and with a distinct spot at the centre, 

 which gives the specific name unipuncta. The hind-wings are 

 somewhat lighter with blackish veins and darker margins. 



Enemies. Were it not for other insects which pray upon the 

 army- worm, the army habit would doubtless be more often 

 assumed and we should have to deal with them more frequently. 

 Ordinarily, however, the parasitic and predaceous insects hold 



FIG. 96. The farmer's friend, the red-tailed tachina-fly (Winthemia 4-pustu- 

 lata): a, natural size; 6, much enlarged; c, army worm, on which fly 

 has laid eggs, natural size; d, same, much enlarged. (After Slingerland.) 



them in check very efficiently and when an outbreak does occur, 

 the later broods of the same season are often entirely destroyed by 

 their insect enemies. Large numbers are always destroyed by the 

 predaceous ground-beetles and their larvae (p. 13), but their 

 most deadly enemies are the tachina-flies (p. 104) These lay 

 from a dozen to fifty eggs on a caterpillar, and the maggots 

 from them enter the body and absorb the juices and tissues of 

 the host, thus soon killing it. When feeding at night the worms 



