MAY 



OvEB «V I •sd IT R tNO 

 BORCRS CKAMOe TO 



06*TiM.r, ST*iie<Pup»f) 



'•t CH-D CORM ANI>WtED 

 STALf^S AMD etMlLAR 



JUNE 



JULY 



LAST Ot/tRWiNTEdi'-'O ' SC^W FlRST- BPOOD 

 BOWERS WiRfcTCBjPAT . BORERS PuPa^e *,*«:) 



CM>M««&C TO MOTHU, CmA'JGE TO WqTM"l 

 MOTM5 ;.AV E&O^ ! MOTHS I.AV ^EOGA 



ANr FinsT . BROOD I *Eco<^E>e«oori " 



BORERS Bt&'N TO ' BEGIN TO "ATTCH 



War on . . . 

 Borer Menace 





N' ORTHERN Illinois farmers art- 

 preparing to wa^c war on the 

 European torn borer as ne\er 

 before. 



"I'hey have uooil reason to. 

 Hntomolo^ists of the State Natural His- 

 tory Survey say the corn borer outlook 

 for ly i8 is a dark one. The rit;ht tom- 



in 191"^. On the other hand, if the 

 corn is planted early and moths eome 

 late, Natural History Survey entomolo- 

 gists says we may well expett a eorn 

 borer outbreak more disastrous than 

 we have yet experienced. 



What can the farmer do to meet the 

 corn borer menace.' Accordini: to 



By JIM THOMSON, Asst. Editor, iaa record 



bination of circumstances is expected to 

 bring out a record number in the north- 

 ern counties. 



The threat is greatest in northwest- 

 ern Illinois — north of Highway 3 » ami 

 West of Highway 51 — where 15 coun- 

 ties have nearly three bore;-, per plant. 

 In at least three of these counties the 

 population averages four per plant. 



Tarther south the borer population 

 ranges from a little over one borer per 

 plant to practically none in southern 

 Illinois. 



Corn borer infestation has been 

 heavy in northern Illinois because the 

 growing cycle of the corn crop has 

 closely paralleled the growth cycle ot 

 the borer. 



If moths come out early and the corn 

 crop is late, the number of borers may 

 be no greater and perhaps lower than 



F.iitomologist G. C;. Decker, the most 

 important single thing a farmer can 

 do to control borers is to plow hi- 

 lields clean. 



A good clean plowing job." Decker 

 says, "can make a tremendous contri- 

 bution to corn borer control. Ninetv- 

 nine per cent of the borers can be de- 

 stroyed in this manner." 



When the corn is abo\c ground and 

 the borer attacks the young plant in 

 damaging numbers, it is necessarv to 

 use a deadly insecticide. DDT is the 

 most practical. It is cheaper and pleiiti- 

 ful. 



When applied at the right time it 

 takes about one pound of DDT to the 

 acre at a cost of SI. 25 to Sl^O. Ex- 

 periments show a 3 to 16 per cent in- 

 crease in corn yields where the Held 

 is treated with insecticide. Failures 



were reported but spraying was yo per 

 cent successful ami paid for the work 

 done j^lus a margin of jvofit. Com- 

 mercial sprayers are expected to be tn 

 the tield this year with rigs worth 

 S:,(i()() to S^.dOi). They charge around 

 SJ.'iO j^er acre including materials. Air- 

 plane applications of DDT run Sv5(i 

 to Si.OO per acre. Ground spravs for 

 the average farm are available for S2i'0 

 to S5()(i. 



-According to j. H. Higger, Natur.il 

 History Sur\ey entomologist, if DDT 

 aj^pluations are made in late June and 

 the crop IS jMcked in f)ctolxr and .No- 

 vember no h.irm will result trom leed- 

 ing it to meat animals. 



He said, however, that it was not 

 advisable yet to feed the corn to dairy 

 animals until further experiments have 

 I ecn made. 



Entomologist J. M. Wright, is studv- 

 ing tlie eltccts cii an imported parasite 

 on the corn borer. He said that results 

 so lar Were iiKoiiclusive but encourag- 

 ing. 



larmers plagued by corn borers this 

 spring are advised to get in touch with 

 their I arm advisers during tiie early 

 part or the growing season in order 

 to know when to apply the insecticide 

 at the proper time. 



This is a sprayer used by the Illinois Natural 

 History Survey in corn borer control experi- 

 ments in northern Illinois last summer. 



Corn borer eggs ore readily visible on the 



underside of the corn leaves. Inset shows 



larva in corn stalk. 



APRIL, 1948 



13 



