u 



lliis (iiiHificr), callod also llio codoii boll-worm in [\\c Soulli, is very 

 generally aiul seriously injurious to corn in the ear. 



The only groups oi' tliese caliM'pillars a,t;aiiisl which it is |)rac(ical)le 

 or necessjiry to use spiM'ial ineasnr(\s of pi-olcdion in Illinois are the army- 

 worm, (he cutwoiins, (lu> wch-worms, and the stalk-borers, injuries by 

 other species IxMiit;- eitluM' too trivial or too inlVc^iuent to warrant special 

 precautions, or, like those oi' th(> corn-worm [llchOlhis (initliicv), uncon- 

 trollable^ by any measuivs as yet tle\ise(l and tested. (•utAVorms, web- 

 worms, and stalk-borers may be \irtually |)re\(Mit(>d from doing serious 

 damage to corn by a proper arrangement and rotation of crops, and by an 

 intelligent selection of times and methods of handling and plowing grass- 

 lands pre\'ious to plaiding them to corn. The army-worm must be 

 excluded from tlu> lield by bai'riers to its progr(>ss when it is on \\\v mai'ch, 

 and destroyed as it colU>cts before such obstacl(>s. .'\ fnlUn* discussion 

 of these various measures will be found in comiection with the sj)ecial 

 articles on tlu; groups themseKcs. 



Colcoptcni: HcctUs. — Approximately ninetx' s|)eci(>s of IxhMK^s have 

 been identi(i(Ml as corn ins(M'ts in (>ith(M' the larval or adult stages, a- few 

 of them in both. .Not moi-e than on(> thii'd of these species, however, 

 need be nieidioned in a nuM'cly economic; list, and if we do not aKcmpt 

 to distinguish for economic pnrpos(>s between the dil'fei'ent kinds of 

 white grubs and of wircwNoi'ms which infest corn under ground, the list 

 so reduced will contain less than a dozen names. 



The habits of the adult beetle and thos(^ of its larva are in most cases 

 so widely different that instances are few in whicii we find both stages of 

 the same insect infesting coi-n, and there is not a single case known to 

 me in wliich a f^iniihtr injiiri/ is done to corn by both. The bee11(> larva> 

 injurious to corn all li\-e uiuUm' ground, and tluMr injuri(\s, consecpuMdly, 

 are confined to the planted schhI, the roots, and the underground part of 

 the stalk. The adult beetles, on the other hand, may eat any pari of the 

 plant, from the seed and roots to the silk and kernels of the ear. 



]iy far the most serious injuries due to beetles are done by tluMr 

 larvso, especiallx' by those known as wireworms, white-grubs, ami corn 

 root-worms. Tlu> oidy injuries b\- the adults themselves deserving to be 

 classed with these, are th<)S(> du(> to the so-calhnl bill-bugs of th(> gemis 

 Splicno'phonis. 



Besides these major (Miemies, whose attacks ai"e largely preventable, 

 there is a, swarm of minor or occasional enemies against which it is both 

 useless and needless to contcMid. Several of the ground-beetles {Carab- 

 idcc), for example, eat the kcMiiel from the tip of the ear, and one small 

 abundant species {Aijonodrrus p<Ulipcs) has occasionally done consid- 

 erable harm by (l(u-ouring the seed and the roots of the young plant. 



Several small species of the family Phalnrridw, and others of th(> 

 Nitidulidce, similarly inf(>st the (>ar, and the larva of one of them. I ps 



