134 



INJUEIOUS INSECTS 



latitude of St. Louis, the bulk of these moths lay eggs, 

 from wliich are produced a second generation of worms, 

 which become moths again late in July or early in August. 

 Exceptionally a third generation of worms may be pro- 

 duced from these. Further north there is but one gener- 

 ation annually. The moths hibernate, and oviposit soon 

 after vegetation starts in spring. The chrysalides may 

 also hibernate, and probably do so to a large extent in 

 the more Northern States. The eggs are inserted between 

 the sheath and stalk, or secreted in the folds of a blade; 

 and mature and perennial grasses are preferred for this 

 purpose. The worms abound in wet springs preceded by 

 one or more very dry years. They are preyed upon by 

 numerous enemies, which so eliectually check their 

 increase, whenever they unusually abound, that the 

 second brood, when it occurs, is seldom noticed; and two 

 great Army Worm years have never followed each other, 

 and are not likely to do so." 



THE WHEAT-HEAD AR^TY WORM. 



(Leucania albilinia, Guen). 



There has of late years appeared, first in Pennsylvania 

 and Maryland, and later in Kansas and Missouri, an 

 insect in many respects like the true Army Worm, but 

 which has shown a peculiar tendency to feed upon the 

 heads of wheat and other small grains. When newly 

 hatched, this differs from the true Army Worm by its 

 black head and later by having five instead of seven pale 

 lines, and six instead of eight dark ones. The habit of 

 feeding upon the grain becomes fixed only when the 

 worms are half gToivn, as before that they attack the 

 leaves, grass, etc. Several parasitic insects diminish its 

 numbers, and it has been suggested that the worms could 

 be greatly diminished by setting traps to attract the 

 moths by means of lights to poisoned sweet liquids. 



