84 



^,A^tI. 



Its injuric^s to corn can he scarc(>ly r(\i;ar(lc(l as more than occasional, 

 its piincipai daniaiic Ix'iiii; (lon(> to wheat, hai'h'v, i-yc, and tinioth\-, the 

 loaves of which arc eaten hy the yonni;- lar\'a% while the older cati^r- 

 jiillars seem to prefer the heads, especially when the ,i;rain is in the milk. 

 It is nocturnal in habit and feeds mainly after dark. 



Its natural food is th()U<i;ht by I'rofessor .lohn H. Smith to l)e the 

 heads and seeds of wild grasses, but it sometim<\s becomc^s so abundant 

 as to compc'l it to migrate in seai-ch of food, when it is likely to infest 



the cultivated cro])s. 



The S])eci(>s is <2;ener- 

 ally conmion and fre- 

 ([uently destructive from 

 Texas, New Mexico, Col- 

 orado, and Nebraska east 

 to the Atlantic States, 

 and north into Canada. 



The egg\s (Fij-;. ()2, b, 

 c, (I) are thrust between 

 the sheath and the stalk 

 of the food plant, and are 

 placed in one to three 

 rows, with frt)ni live to fifty eggs in each. They are flattened, cylindri- 

 cal, irregularly corrugated, pale yellow at first, but become slate- 

 colored as the embryo develops. 



The life history is well delincHl. The species winters in i\\v pu|)a 

 state, and the moths come out in May, being usually most abundant 

 about the middle of that month. Eggs are soon laid, and hatch in t.hn^e 

 to fjve days. The caterpillars gain tlueir growth in three or fom- weeks, 

 which brings them to full size in July. The pui)al stage is ivn to fift(HM\ 

 days in length, moths emerging from late July to August, and laying 

 eggs for the second brood of larvic, which come out in Sept(Mnber and 

 pupate before winter sets in. The ]>upa for the sununer brood is found 

 under weeds and rubbish, or just under ground, but the hibernating 

 pupae are found about six inches below the surfac(>. Th(>y luv mahogany- 

 brown, the abdomen terminating in a stout horny point. 



The only notable injury to corn done by these caterpillars is eviilentl>- 

 due to migration at times of excessive abuntlance, — a movement which 

 coukl be arrested, if necessary, by measures found efficient against the 

 army-worm. 



a b 



Fi(i. 63. l'''iicea of Army-worm larvw: n, the Wheat-liead 

 Army-worm, Lcuranin albUiiu'n; b, tlie true Army-worm, I,, 

 unipunctn. J'^iilarKcd. 



