160 EXPERIMENT STATION RECORD. 



The fruit tree leaf -roller (Archips argyrospila), G. W. Hebbick (New York 

 Cornell Sta. Bui. 311, pp. 219-292, pis. 4, figs. 3). — As noted in a previous ac- 

 count (E. S. R., 26, p. 758), this leaf-roller suddenly came into prominence in 

 the spring of 1911 as a serious pest to apples and a minor one to pears in New- 

 York orchards. 



The species was first described as of economic importance in 1869 when 

 Packard reported it as attacking the cherry tree, but eastern growers have 

 been comparatively free from its ravages. It has been bred by the author 

 from larvas ou the apple, pear, sweet cherry, wild cherry, black walnut, and 

 mountain ash. At Bethany Center the larvae were found in abundance on plum, 

 pear, quince, apple, and cherry trees. 



" The larvae appear as the buds are bursting, and begin to attack the unfold- 

 ing leaves. They bend the leaves over and tie them together with silk. Within 

 this sort of nest the larvae live and eat the leaves. As soon as the blooms' appear 

 the larvie begin to eat ofE the blossom stems and tie them together with silken 

 thread:^, along with the leaves surrounding the blossom cluster. This webbing 

 and tying together of the blossom clusters is a most pernicious habit because 

 it interferes seriously with spraying for the codling moth. In one Baldwin 

 orchard in which the larvae were very abundant, the blossom clusters were so 

 webbed together and covered over with silk, dried petals, and leaves that it 

 was almost impossible to get the spray mixture into the calyx cup. As soon 

 as the young apples or pears begin to set they are tied together with silk, while 

 the larvae live inside, and gnaw cavities into the sides of the young fruit. . . . 

 In New York orchards during the past season a very large number of pears 

 and apples were totally destroyed by the lar-\-jE, and many others w^ere seriously 

 marred and deformed. . . . The larvae also work on the leaves, rolling them 

 and living within the roll. Here, effectually hidden, they feed on the tender 

 tissues of the leaves." 



The pest undoubtedly passes the winter in New York State only in the egg 

 stage, one generation a yeap apparently being the normal habit. The eggs are 

 laid in June in small oval convex patches on. the bark of the smaller twigs, the 

 major number being deposited during the middle days of the month. The eggs 

 remain ou the trees until the following May, or a period of more than 10 months. 

 In 1911, eggs hatched as early as May 4 and were found hatching in the field in 

 abundance on May 9. 



" When the larva becomes full-grown it spins a very thin, flimsy web in a 

 rolled leaf, or between the leaves that are tied together, and changes to a 

 pupa. ... In the cages in the insectary the pupal stage lasted 9 to 12 days. . . . 

 Our records during the season of 1911 show that the moths were emerging 

 nearly every day from June 5 to June 21, with the latest moth appearing 

 June 24. . . . It is evident that by the middle of June the moths were emerging 

 in greatest numbers and that they were almost entirely out before July." 



Four species of hymenopterous parasites were reared from larvae and pupae 

 in cages. Many primary and secondary parasites and at least 1 tertiary parasite 

 were reared in the field. Pimpla conquisitor was the parasite reared in greatest 

 numbers, the others being Amicroplus sp., Phytodietus vulgaris, Sijmpiesus sp., 

 Pvmpla inquisitor, Olypta simplicipes, and Carcelia nigropalpus. 



Methods of control have been summarized by the author as follows : " We 

 would advise a thorough drenching of the trees with lime-sulphur at scale 

 strengths for a dormant spraying to prevent the eggs from hatching, provided 

 one is going to spray for the San Jose scale or the blister mite; we are not 

 yet ready to recommend a spraying for the eggs of the leaf-roller alone. This 

 application should be made as late as possible in the spring before tbe buds 

 burst. We would advise a thorough spraying with arsenate of lead at the rate 



