PEAR AND QUINCE INSECTS 217 



In New York the eggs for the second brood arc; hiid during late 

 July and early August. Normally there are two broods in the 

 North, but three have been reported in the latitude of Wash- 

 ington, D.C. 



The larvae feed on the upper surface of the leaves eating only 

 the epidermis and leaving the skeleton of veins and the lower 

 epidermis to turn brown and wither up. Badly injured leaves 

 fall and the tree may be entirely defoliated by midsummer; 

 the fruit becomes stunted, fails to mature, and the vitality of 

 the tree is so weakened that fruit buds for the next year's crop 

 are not formed. Sometimes the tree will put out a new crop 

 of leaves, but these in turn may be destroyed by the second 

 brood of slugs. In cases of such severe infestation the orchard 

 has the appearance of having been swept by fire. Fortunately 

 this pest is rarely troublesome for a series of years in the same 

 locality, probably being held in check by a minute egg parasite. 



Treatment. 



When only a few trees are to be treated the slugs may be 

 destroyed by one or two applications of freshly slaked lime 

 dusted on the leaves. White hellebore, one ounce to three 

 gallons of water, has also given good results. For commercial 

 orchards arsenical sprays are more satisfactory. Arsenate of 

 lead because of its greater safety and effectiveness is prefer- 

 able to the older arsenicals, Paris green and London purple, and 

 should be used at the rate of 4 pounds to 100 gallons of water. 

 The slugs can also be killed by spraying with "Black Leaf 

 40" tobacco extract, 1 pint in 100 gallons of water, adcHng 

 4 or 5 pounds of soap to make the liquid stick and spread 

 better. 



References 



Nev. Agr. Exp. Sta. Bull. 10. 1890. 



U. S. Bur. Ent. Circ. 26. 1897. 



Col. Agr. Exp. Sta. 15th Kept. pp. 11-13. 1903. 



Wash. Agr. Exp. Sta. Bull. 65, pp. 12-14. 1904. 



