PREVENTION. 143 



a cell in the earth, in •which it is protected from wet 

 and sudden changes of temperature, or it seeks or pre- 

 pares a safe resting-place for its change, or for a time; 

 and so long as the caterpillars are thus protected no 

 amount of cold to which they are here exposed will, 

 as far as we know, do them the least harm. But if 

 they are thrown out of these shelters to the influence 

 of drying winds or hot sunshine, or to lie soddening 

 helplessly on the surface in moist or muddy ground, 

 or to being frozen in these states, then their constitu- 

 tion will not bear it. To quote one of our chief 

 American authorities, " It is evident that freezing 

 does not injure the cut-worms " (as these surface 

 caterpillars are called in the States), for nature has 

 prepared them for it ; but freezing in connection with 

 loose ivet soil will kill the chrysalids as quickly as 

 it will the worm or caterpillar. This is one of the 

 great principles of prevention : — Turn out the insect 

 pest from its natural shelter, ivhen it is in such a condi- 

 tion that it cannot regain it or make a new one. It 

 takes a little observation of the habits of the creature 

 to manage this properly. 



If the caterpillars are turned up too soon, that is, 

 either before they are torpid, or before they have 

 changed to the chrysalis, they will simply go down 

 again. If the soil is turned up when they are gone 

 down very deep, they will not be the worse for what 

 has been done above them. Each worker must look 

 a little for himself, for dates and habits differ with 

 climate and other things ; but a little careful observa- 

 tion made by turning over the earth, so as to see where 

 the creatures are, will be well repaid. They are quite 

 large enough to be easily seen, if they are in numbers 

 to need attention. This principle may be worked both 

 in winter and summer, — with caterpillars that turn to 

 chrysalids under ground or in cocoons above ground, 

 and with those that frequent leafage of trees or roots 

 of grass, as well as those we have spoken of. 



It should always be remembered that when a con- 



