Seasonal history and biological control of San Jose scale Quadraspidiotus perniciosus (Comstock) (Diaspididae: Homoptera) on apple in Kashmir

Abstract

The San Jose scale completed two generations with a partially incomplete third generation which over-wintered from November on apple trees in Kashmir. The population entered hibernation in all stages but nymphs of first instar survived. The overwintering nymphs became active in middle of March. The winged males emerged in late April. The females gave rise to first generation crawlers in the third week of May, about one month after the emergence of males. The second generation crawlers started emerging in the third week of July and development was completed in the first week of September. Nymphs of the third generation started appearing in the last week of September which stopped development in the end of November and entered hibernation. Series of releases of laboratory multiplied parasites Enearsia (=Prospatella) perniciosi (Tower) and Aphytis sp . ( proclia ) were made in four abandoned apple orchards. The pretreatment count of apparent parasitism of San Jose scale ranged between 4.97 and 15.60%. As many as 1,16,375 adults of E. perniciosi and 2,81,461 adults of Aphytis sp . ( proclia group) were released during 1984. The recovery tests indicated an increase in apparent parasitism between 9.13 and 40.20%. During pre-treatment survey, besides E. perniciosi and A. proclia . Marietta cernesi Howard and Azptus kashmirensis Narayanan (Aphelinidae:Hymenoptera) were, also obsorved from the sample twigs.