137 



nearly g-lobular eg^g-s, placed in three or four layers, stuck together 



and imbedded in a ji^elat- 



inous substance which 

 g-ives the mass a grayish 

 white surface and a con- 

 vex form. The eggs hatch 

 about the middle of May, 

 and the young caterpillars 

 begin at once to devour 



^->. 



>/•. 



-^ 



\ 



Fiof. 26. Thk 'I'lissuc.k Moi II, Uir\;i. 



the leaves of the tree 

 on which they are 

 placed (Fig. 26). A 

 careful nurseryman 

 will always strip 

 from the twigs of 

 his trees, before ship- 

 ping, any suspicious 

 object of this sort, 

 and the caterpillars 

 can be poisoned with the usual arsenical sprays 



Kii 



The Tussock- 

 moth, male. 



Fi?. 28. 



TlIK I'USSOCK- 



MOTii, female. 



The Applr-scab. 



This is a fungous disease of the leaf and fruit of the apple, 

 occurring throughout the state wherever this fruit is grown. The 

 technical name of the fungus producing it is Fnsirlddiidii 

 dcndrilicitni. "It forms soot-colored spots with indefinite out- 

 lines, generally on the upper side of the leaves (Fig. 29). 

 These spots vary from an eighth to half an inch in diameter, often 

 fusing and occupying most of the surface, then causing the leaf to 

 blacken, curl up, and fall ; the deadened part sometimes falls out, 

 leaving holes ; the growth sometimes follows the veins, and thus 

 assumes a branched form. Petioles and young growth of twigs 

 are attacked. Fruit stems are occasionally injured so that young 

 apples fall. Spots also appear on growing fruit, producing there 

 what is known as scab, or black spot. (Fig. 30.) 



'^ It attacks both young and old trees, being especially preva- 

 lent in nurseries among trees that have been left in the rows after 

 they are too old to sell, and have thus become crowded and, it may 

 also be, weedy. Some varieties are more subject to it than others, 

 but crowded trees and those on low or badly drained soil are liable 

 to it without much regard to variety. Its injury to the foliage 

 consists in reducing the size of the leaves, in causing them to fall 



