INSECTS. 115 



perature of 70 degrees, they would all die before the win- 

 ter was ended, particularly if the plants were of a half 

 hardy nature. If tropical species, they might stand it 

 hotter, but all plants quickly become enfeebled when 

 kept at high temperature and away from the light. 



CHAPTER XXXVH. 



INSECTS. 



When insects attack plants in the greenhouse, parlor, 

 or anywhere under cover, we can generally manage to 

 get them under control, but when they attack plants in 

 the open air, it is according to our experience, difficult 

 to destroy them. Insects are injurious to plants in the 

 open air in two principal ways : some attack the branches 

 and leaves, and others infest the roots. When insects 

 attack the roots of a plant, we have been able to do but 

 little to stop their ravages. We can manage somewhat 

 better with those attacking the leaves, but even this di- 

 vision of the enemy is often too much for us. As a pre- 

 ventive, we would strongly advise that birds of all kinds 

 should be encouraged. Since the European sparrows 

 have favored us with their presence in such numbers, in- 

 sects of nearly all kinds have much decreased. Most 

 people will remember the disgusting " measuring worm " 

 that festooned the shade-trees in New York, Brooklyn, 

 and other cities ten years ago ; these made their exit al- 

 most in proportion to the increase of sparrows, and now 

 hardly one is to be seen. The same is true of the Rose 

 slug. In my rose grounds, a few years ago, we were 

 obliged to employ a number of boys for weeks during the 

 summer to shake off and kill the Rose slug in order to 



