INJURING THE LEAVES. 39 



trees, and migrate — we know not where, but proba- 

 bly to some annual plant that is succulent in mid- 

 summer. Here, apparently, they continue breeding 

 until autumn, when they return to apple, and the 

 winged females may be found establishing colonies 

 of the wingless, egg-laying form upon the leaves. 

 The males are apparently developed on the same 

 plant that the winged females are. The small, oval 

 eggs are now laid on the twigs and buds, and the 

 cycle for the year is complete. 



Remedies. — These lice have various natural ene- 

 mies that destroy them — especially the lady-bird 

 beetles — but it is often necessary to spray infested 

 trees with kerosene emulsion, or a strong tobacco de- 

 coction to get rid of them. The latter may be made 

 by soaking refuse tobacco stems in hot water, and 

 then draining the liquid off. 



The Canker Worm. 



Anisoph ryx pometaria. 



Apple orchards are occasionally infested in spring 

 by a looping caterpillar, or " measuring worm," that 

 feeds upon the parenchyma of the leaf, leaving the 

 net work of veins, so that the foliage looks brown 

 and scorched. These are canker worms, of which, 

 according to Dr. Riley's observations, we have two 

 distinct species. But both are similar in habits and 

 injuries, and for the present purpose only one will 

 be discussed. This is called the Fall Canker Worm. 



