50 BUI.I.ETIN 64. 



hibernation. In the spring they come forth, complete their 

 growth, pupate near the surface, and later the adults emerge. 



Economic importance. — Though the various 

 species of Cravibus are common, they have rarely 

 attracted much attention as destructive insects. This 

 is due to their insidious methods of work. Unless the 

 damage they do is very serious it is hardly noticed 

 or, if noticed, attributed to other cau.ses. As the 

 larvae live a retired life close to the surface, eating 

 mostly at night and remaining in their nests during 

 the day, they are rarely seen. L,ike most larvae they 

 feed most voraciously just as they are completing ^^^' c~Iib^i 

 their growth ; consequently, when the damage is i^'s, enlarged. 

 noticed most of the larvae are hidden in their retreats where they 

 pupate. In these places none but an experienced entomologist 

 would find them, or would think of associating the damage done 

 with the harmless appearing moths that fly later. 



Hardly any farmer would think seriously of the loss of only one 

 stalk of grass in ten, 3^et the aggregate for the country at large 

 would be enormous. Not only is the damage to a crop where 

 nothing short of a serious injury would attract attention, but the 

 damage is distributed throughout the growing season. As a 

 general rule each species is most destructive at a different time 

 from the other species of that locality ; hence, species of Crambiis 

 pre}- upon the grass as a succession of small armies. Could the 

 loss caused by these species come at one time in the year their 

 destructive power would be better appreciated. Less than a 

 third of the species may be classed as of economic importance, 

 but these possess a capacity to cause almost infinite loss if the 

 conditions are favorable. 



In 1880 and 1881 the conditions were favorable for the devel- 

 opement of several species of Close Wings. The Vagabond 

 Crambus (C vulgivagellus) was the chief offender, though the 

 Dried Crambus {C. inter minelbis) was associated with the former 

 in the devastation. In the latter part of May, 1881, Dr. Lintner 

 was notified of a " formidable invasion of the grass lands of St. 

 lyawrence Count}'-, N. Y., by the army worm." He writes: 

 " The ravages had only been observed during the preceding ten 

 daj's, but already had they reached such magnitude that many 



