24 INSECTS INJURIOUS TO VEGETABLES 



Large corporations like seedsmen, canners, and picklers, plant 

 very extensive areas and employ others in growing the same 

 crops. Such firms provide seed and machinery, and keep posted 

 on what will benefit not only their own interests, but those who 

 labor for them. This applies to the means of controlling in- 

 sects, including the purchase of insecticides and spraying ap- 

 paratus, and by purchasing at wholesale they greatly reduce the 

 cost for themselves and their co-laborers. The scope of this 

 work might be extended (and perhaps is in use in some measure) 

 to those who grow on a smaller scale, the farmers of a given 

 locality having a community of interests pooling their interests 

 for the purpose. Growers having small areas are often so 

 little troubled with insects that it does not pay to buy expensive 

 outfits ; and insecticides cost at retail frequently two or three 

 times as much as when purchased in quantity. For example, 

 bisulphid of carbon, a standard remedy for the melon aphis, 

 bean and pea weevils and root-maggots, costs only lo cents a 

 pound in fifty-pound lots, and from 20 to 30 cents when bought 

 in smaller quantity. This difference could be saved by the co- 

 operation of several neighbors, and it could be extended to the 

 purchase of expensive spraying outfits. 



Co-operation is of especial value in the control of insects such 

 as the squash bug, cucumber beetle, harlequin cabbage bug, and 

 cabbage looper, that cannot be held in subjection by ordinary 

 poisons. If growers who suffer most could induce neighboring 

 farmers to employ clean farming methods and crop rotation, the 

 ravages of these pests would be greatly reduced. The harlequin 

 cabbage bug is quite resistant to poisons, and since about the 

 year 1900 it has been so nearly exterminated in its northern 

 range, that if farmers would work together when it again makes 

 its appearance northward and use trap crops over large areas, 

 for example over townships, the insect might be prevented 

 for several more years from regaining its lost foothold. This, 

 with clean methods of cultivation, would leave little else neces- 



