298 THE CANADIAN NATURALIST. [Sept. 



Thus, at an expense of only twenty-two shillings and sixpence, 

 an acre and a half of turnips, worth from £^ to £7 sterling, 

 or more, was saved ; while, as the boys could each collect 600 

 per day, thirty days' employment was given to them, at 9d. 

 per day, which they would not otherwise have had. 



When the caterpillar has attained its full growth it changes 

 into a chrysalis, which may be found attached to fences and 

 hothouses in the immediate neighborhood of the fields where 

 the cabbages are grown. In my opinion this is one of the 

 best times for their destruction. Half a dozen boys could 

 gather and destroy thousands in a day for a small remunera- 

 tion. A friend of mine, in the city, has gathered handfuls 

 of them in this stage, and destroyed them. 



A great deal may be done by netting them in the perfect 

 or butterfly state, which, no doubt, is the best and surest 

 method. Bring the boys into the field with nets, and, by 

 capturing all they see, they prevent the depositing of the egg, 

 and thus cut ofi" the supply. When the larvae have once got 

 among the plants, to any extent, the destruction commences. 

 When they appear in great numbers the best plan would be 

 to plough up, and plant neither cabbages nor turnips on the 

 farm, for a time, in the infested localities. This, of course, 

 would be only in extreme cases. 



Encourage the small birds on the farms: abstain from their 

 destruction : they are undoubted benefactors of the agricul- 

 turist. It would also be a wise plan to turn fowls into the 

 fields, and allow them full scope : they will give a good account 

 of themselves. Nature will also help, no doubt. The innumer- 

 able ichneumons will soon find out the larvae of the cabbage 

 butterfly ; in fact, they have already found them this summer. 

 Their operations, on our behalf, will be felt a few seasons hence. 



Insects, when first introduced into new countries, may find 

 this food more juicy or better suited to their tastes than in 

 the countries they left, and, therefore, commit greater havoc; 

 besides, there are what are termed " insect years," — that is, a 

 certain species will be noticed in greater abundance one year 

 than another. This may be accounted for by the mildness or 

 severity of the season ; or it may be influenced, to a very con- 

 siderable extent, by " parasitic attacks," which latter is one of 

 the many ways which nature takes to keep in check the many 

 varieties of insects. We believe firmly that all insects, as well as 



