Department of Entomology-Apiculture, Dr Y. S. Parmar University of Horticulture and Forestry, Solan
Preference of Argyresthia conjugella Zeii. (Yponomeutidae: Lepidoptera) to five cultivars of apple was studied in three selected localities of district Kinnaur in Himachal Pradesh during the years 1982 to 1984. Golden Delicious with 52.5 per cent infestation was the most preferred cultivar followed by Red Gold (39-4 per cent), Royal Delicious (33.7 per cent), Red Delicious (31.8 per cent) and Crab apple (26.2 percent). Shape of the crown, leaf formation and fruit bearing habit of the tree, colour of the fruit and its maturity were responsible for relative preference of apple fruit moth to various cultivars. Year to year and place to place differences in ecological conditions also affected the quantum of infestation in different cultivars. Corre lation studies indicated a highly positive correlation coefficient (4−0.55 to +0.89) between number of laravae entered and number of larve developed in all the five cultivars. Correlation coefficient between number of larvae developed and number of seeds per fruit was non-significant in self-compatible and significantly positive (+0.45 to 0.56) in self-incompatible cultivars.
