March, 19in. 



SCIENTIFIC AGRICULTURE 



129 



and hence lost; the infested plants in addition showed 

 a 7Y> p.c. decrease in weight of the non-iiifeste(i 

 kernels, 55 p.c. of the cobs were u.seless for sale as .seed 

 on the col) as no one is likely to buy seed corn on the 

 cob, part of the kernels of which show insect attack. 

 The other olenients of loss, as yet not definitely estim- 

 ated, inclnde the undoubted and marked loss in com- 

 mercial grade of the shelled corn due to the presence 

 of the devoured grains and the light weight of the grain 

 from infested stalks, the reduction in germination effi- 

 ciency and the loss of feeding material in the stalks 

 due to the increase of crop refuse. To this must be 

 added as well the decrease in value of the infested 

 stalks, arising both from material actually eaten by 

 the borer, and the loss of substance due to interference 

 with the plants' activities. Thus in the flint corn the 

 total loss is very imjiortant and must interfere to 

 almost a prohibiting degree with the market value of 

 the ci"op. When it is realized that in this corn field 

 there was onl.y an average of 3 borers per stalk and 

 that in Boston in certain corn fields the average was 

 46 per stalk and that in our field we have found as 

 high as 16 in one stalk, it behooves us to be up and doing 

 and to keep within the narrowest limits the ravages of 

 this pest. We have as yet no warrant for thinking 

 that this pest has attained in Ontario to anything like 

 its possible degree of infestation or the possible damage 

 it may cause. 



The condition of dent corn in this vicinity was mark- 

 edlj^ different. Though the field infestation of a crop 

 of dent about 400 yards from the flint field discussed 

 above was 45 p.c, yet the loss was remarkablj^ slight, 

 only 7.7 p.c. of the tassels being broken and 8 p.c. of 

 the stalks broken over. Practically none of the cobs 

 were attacked and the grain loss, if any at all, would 

 not be worth mentioning. 



Even where dent ami flint were grown mixed and 

 the flint cobs were running 38 p.e. infested, the dent 

 cobs of which there were but few, only showed an in- 

 festation of about 9 p.c. The dent stubble, likewise, 

 seems to l)e a markedly less common place than that of 

 flint stubble for spending the winter. This is shown 

 not only in pure stands hut in mixed stands as well. 



However avc should not put too great dependence 

 upon this apparent preference for flint. When in the 

 Boston region last fall we observed that the dents in 

 the sample plots were very severely attacked and look- 

 ed a wreck — as high as 25 borers being found in a single 

 stalk; these, of cour.se, being second generation larvae. 

 Thus we have every reason to suppose where flint corn 

 is not present in sufficient quantitj^ to serve as a bait 

 and more attractive food suppl.v (as is the case of the 

 district from west of St. Thomas to Essex County) and 

 as the numbers of the borer increase, the dent corn 

 will become more and more severely attacked. 



This general increase of attack we should expect to 

 be the most severe in the next few years. In course 

 of time, however, parasites already prej-ing on the 

 borer to a very slight extent in the Boston infestation 

 —will follow the boi-er as it spreads and eventually 

 we hope hold it in cheek to such a degree that its 

 ravages may be reduced to a point where careful rout- 

 ine farm practices will keep it from being a serious de- 

 triment to the corn industry. 



The natural spread of these parasites will be assisted 

 as fully as possible by the entomologists through artifi- 

 cial means, such as distributing to the infested areas 

 such parasites as seem of value. At the i)resent time 

 the V. S. Bureau of Entomology has established a lab- 



oratory in Southern P>ance for the collection and for- 

 warding to America of parasites of particular value in 

 Euro])e. The I)oniini<Ju Entomological Branch has been 

 assured by the U. S. Bureau of Entomology that when 

 these slii])nients of parasites from Prance arrive in 

 goodly numbers, consignments will be forwarded 

 to the Canadian Government for the benefit of oiu- own 

 corn growers. 



One of the most promising and valuable features of 

 dealing with this pest has been the spirit of cooperation 

 evidenced between the various entomological services, 

 the agriculturists, and the press. As the matter is of 

 vital importance to the United States, the province of 

 Ontario, and the Dominion of Canada as a whole, this 

 cooperation cannot but coiitinue and he reflected in the 

 effectiveness and speed with which this insect M-ill be 

 brought under control. To these forces we fully expect 

 to add the hearty cooperation of the growers them- 

 selves; then will we have attained the almost perfect 

 condition in which a maximum of result will be secured 

 with a minimum of delay, loss and inconvenience. 



What part can the growers play in this work? All 

 can do their part in preventing the distriiiution of the 

 borer by assisting whole heartedly in the maintenance 

 of the quarantine and by impressing those who are 

 less familiar with the dangerous possibilities of the pest, 

 with its seriousness. 



To those of us who are fortunate enough to live in 

 the non-infested territory we recommend eternal vigil- 

 ance : 1. Avoid corn on the cob from the infested areas 

 and all such materials as are likely to carry the borers. 

 2. Watch your corn for broken tassels and borings in 

 the stalks. Whenever these are noted advise the Dom- 

 inion Entomologist. Department of Agriculture, Ottawa 

 or the Provincial Entomologist, (iuel])li, of such find- 

 ings. 



To those who are in the infested areas and whose 

 corn crop is infested with the borer either slightly or 

 severely, and whether growing flint or dent corn, the 

 following practices are advised : 



1. Keep corn crop and fence rows clean of weeds, as 

 these are food jilants of the borei-. 



2. Cut dent corn crop as low as is possible with the 

 corn binder. This will leave very few borers in the 

 stubble. 



3. Cut flint corn preferably at the surface of the 

 ground by hand with hoes, or if a binder is used cut as 

 low as is possible. The binder however, leaves quite a 

 mimber of borers in the stubble. 



4. Clean up crop refuse in all infested corn fields by 

 hand rake or horse rake, even at some expense as this 

 wiU'contain thousands of borers i)er acre. This refuse 

 should either be burned, fed or put in the silo; prefer- 

 ably burned or put in the silo. 



5. Avoid above all things, allowing pigs to harvest 

 the corn. They kill practically no borers and nuike it 

 im])ossiblc to have a clean field. 



6. Consider a silo from the point of view of combat- 

 ing the borer, the most important part of the farm 

 equipment. The fermentation of the corn in the silo 

 kills the borers. If all the corn will not go into the 

 silo in the fall, put it in later after the ensilage has 

 settled down. 



7. If the silo is impossible and corn stalks have to 

 be fed, either shred before feeding or see that the un- 

 eaten parts are set aside in a heap and burned in the 

 spring before the thaw. Do not throw them into the 

 liedding or loose mainire iiile. If they nnist be kept 



