128 



SCIENTIFIC AGRICULTURE. 



March 1921. 



from 5 to 50, overlapping, fish-scale-like eggs. The 

 eggs hatch into the larvae or eaterpillai"s which alone 

 are responsible for the damage. 



The caterpillars or borers spend their lives in the 

 corn stalks upon which they feed and within which they 

 pass the winter. In the spring with the beginning of 

 warm weather the borers begin to feed again and go 

 through the changes preparatory to emergence as moths. 



The habit of wintering in the stalks scenes to be the 

 easiest point of attack and hence later in the discussion 

 we recommend low cutting of the plants, the ensiling 

 of the corn and the destruction by burning or feeding 

 of the crop refuse in field and barnj-ard. 



The general field attack (See Fig. 2) on the flint corn 

 in tihe Union Village region and extending as far nortji 

 as Port Stanley runs from 70 p.c. — 99 p.c. of plants 

 attacked. In the field studied 93 p.c. of the corn stalks 

 were infested and a few of the weeds. This attack upon 



the corn plant was general and involved any part above 

 ground, the various parts of the stalks and ears in the 

 field were infested in the following proportioiLs : tassels 



50 p.c, joints 17 p.c, interjoints 25 p.c. cob shanks 



51 p.c. cobs 55 p.c, stubble 57 p.c. 



The attack resulted in the following condition in the 

 crop — 51 p.c. of the tassels fell off and 42 p.c. of the 

 com stalks broke at one or more points of infestation 

 (which may be at anj^ height) and fell either complete- 

 ly or partially. This breaking of stalks not only adds 

 to the difficulty of harvesting but also adds greatly 

 to the crop refuse left in the field, involving a loss of 

 feeding material and providing winter quarters for a 

 large number of borers. In another field of mixed 

 flint and dent corn the crop refuse alone wai> carrying 

 7245.0 borers per acre over the winter. 



It was t.he attack upon tl'.ie cob. however, which caused 

 the greatest loss. 8 p.c of the kernels being devoured 



fested and a few of the weeds. This attack upon the greatest loss. 8 p.c of the kernels being d 



DISTRIBUTION Of TM[ ATTACK Of THE CUROPtAM COINBORER UPON PIWTCORN. Union \^%. 0,1. 1920. 



(Prepared btj fke Catotnolopcdl 5rdm.^h. Deph A^riailfure-Oftdvd) 

 ATTACK —J ^Genera! field dlldcL - EFFECT Of ATTAa 



Plant Attacked. 



^NT ATTACKED. ^^^ 



Field Attack uij 



TA5SCL 



JOINTS 



NUBBINS 



STUBBLE 



50^ TASSELS BQOKCN OFF 



3': GCAIN DCVOUPED. 



7'J LOSS IN WEIGHT OF 

 UNDEVOUIJED KERNELS. 



55? Of EAC5 UNSALEABLE AS 

 SEED ON THE COB. 



9t LOSS OF GCADC AS GRAIN. 



91 LOSS OF GECMINATION 

 EFFfCIENCY. 



9? LOSS IN STALKS AS FODDEB. 



9e LOSS FEEDING VALUE OF 

 STALKS. 



9;^ INCREASED COST OF 

 HACVESTING. 



AZi STALKS BROKEN 



Fig. 2. Wall chart indicating distribution of Infestation 

 and consequent damage Ijy the European Corn Borer in a 

 flint corn field. Union Village. Ont., 1920. 



