10 HANDBOOK OF NATURE STUDY 



often cause his death. If he lives long enough to change 

 into a chrysalis, the little maggots still live in him and 

 finally kill him, before he can change into a butterfly. The 

 little maggots then remain in the chrysalis until they have 

 transformed themselves into flies. These little flies are 

 either Ichneumon Flies or Tachina Flies. Nearly every 

 caterpillar has one or more of these little flies as his special 

 enemies. If you open a considerable number of chrysalides, 

 you are very apt to find the little flies or their cocoons in them. 

 Another class of very useful insects are the Ladybirds or 

 Ladybugs. You will often find them and their larvae on 



plant lice, which they 

 devour by the dozen. 



Besides the insects 

 eaten by birds and de- 

 stroyed by other insects, 

 a great many are killed 

 by frost and by cold, 

 rainy weather. Some- 



FIG. 2. LADYBUG AND LABV^ ON ROSE times tlie y starve in 

 LEAF. great numbers, because 



their food gives out. 



What becomes of the millions of insects when cold weather 

 sets in? Where do they come from in spring? Try to 

 answer these questions for a few insects by your own 

 observation. 



NOTE TO TEACHER. For a more detailed account of the insects 

 just studied, see 



Oomstock. Manual for the Study of Insects. 

 Harris. Insects Injurious to Vegetation. 

 Saunders. Insects Injurious to Fruits. 



For injurious insects in your neighborhood, see your State Reports, or 

 write to your state entomologist, sending specimens with your in- 

 quiry. See also, A Study in Insect Parasitism, by L. O. Howard, 

 Department of Agriculture, Washington, D. C. 



