16 BULLETIN 1213, U. S. DEPARTMENT OF AGRICULTURE 



sp. was reported from Nova Scotia (22, p. 23). Two individuals of Winthemia 

 guadripustulata (Fab.) were reared at Wallingford from pupae from bud 

 moth larvge which were collected in the field when nearly full-grown. They 

 were determined by Dr. J. M. Aldrich. 



CONTROL 



A study of the life history of the bud moth suggests as the most 

 favorable opportunity for its control the spring feeding period, as 

 during this time the larvae feed to a considerable extent on exposed 

 leaf tissue. 



During the hibernating period the larva is protected by a com- 

 pactly woven silken shelter, and even the strong solutions used in 

 dormant spraying are not likely to penetrate to the larva. Scott 

 and Paine (18) report that applications of lime-sulphur and soda- 

 sulphur solutions at dormant strength had no effect on the larvae 

 of the lesser bud moth while they were still in their hibernacula. 

 Working with the bud moth, Wilson and Moznette (20) found that 

 oils applied during the dormant season had no effect on the pro- 

 tected larvae. In December, 1921, at the Wallingford station, a 

 small number of twigs bearing hibernacula were dipped in the solu- 

 tions usually used for dormant apple spraying: Lime-sulphur 1 to 

 9, the same with the addition of nicotine sulphate 1 to 800, and a 

 miscible oil 1 to 15. This was done on a warm day, and the twigs 

 were placed out of doors under normal conditions. Examination 

 two weeks later showed that none of the larvae had been affected by 

 the treatment. The experimental evidence just cited is sufficient to 

 indicate that little is to be expected from dormant applications. 



For the control of the lesser bud moth, the so-called delayed 

 dormant application of lime-sulphur, put on as the buds are showing 

 a small amount of green, was effective, presumably acting as a repel- 

 lent, keeping the newly emerged larvae from entering the buds. 

 With the bud moth, however, emergence from hibernation occurs 

 a few days too late for the effective use of this treatment, as in 

 Connecticut, at least, few of the larvae leave winter quarters before 

 the leaves have begun to unfold. DuPorte (21) reports a similar 

 observation in Quebec. 



Experiments were conducted on a limited scale at Wallingford 

 with applications at the time when the apple blossoms showed pink, 

 and again at the time of the usual calyx application. 



On April 21, 1921, about the time the blossom buds were showing 

 pink, a number of infested apple twigs were brought in ; 23 of them 

 were sprayed with powdered arsenate of lead, 1 pound in 50 gallons, 

 and 17 were left as checks. After being sprayed the twigs were 

 placed in water, to keep them fresh, and examined on April 27. At 

 the time of this experiment the characteristic bud moth nests had not 

 been made, and a number of lesser bud moth larvae were included. 

 The results are given in Table 6. 



