Biology and Management of Woolly Apple Aphid (Eriosoma lanigerum) in the Mid-Hill Ecosystem of Garhwal Himalaya, Uttarakhand, India
Yogesh Chandra
Department of Entomology, College of Horticulture, VCSG Uttarakhand University of Horticulture and Forestry, Bharsar, Pauri Garhwal, Uttarakhand, India.
Sanjeev Ravi *
College of Hill Agriculture, Chirbatiya Campus at Ranichauri, VCSG Uttarakhand University of Horticulture and Forestry, Bharsar, Pauri Garhwal, Uttarakhand, India.
Harshit Gupta
Department of Entomology, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya, Uttar Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: To study the biology and life cycle of woolly apple aphid, Eriosoma lanigerum (Hausmann), under laboratory conditions and to evaluate the efficacy of selected chemical and biorational treatments for its management under mid-hill conditions of Garhwal Himalaya.
Study Design: A laboratory-based biological study and a field experiment for the evaluation of pest-management treatments.
Place and Duration of Study: Department of Entomology, College of Horticulture, VCSG Uttarakhand University of Horticulture and Forestry, Bharsar, Pauri Garhwal, Uttarakhand, and KVK Fruit Orchard, Bharsar, Pauri Garhwal, Uttarakhand, during 2023–24.
Methodology: Woolly apple aphid colonies collected from infested apple trees were maintained on excised apple twigs under laboratory conditions. Individual aphids were reared separately and the duration of each nymphal instar, total nymphal period, adult longevity and total life cycle were recorded. For management studies, four insecticides and five biorational treatments were evaluated along with an untreated control. Treatments were applied twice, and aphid colony populations were recorded before treatment and at 3, 5 and 7 days after each spray.
Results: The woolly apple aphid completed four nymphal instars, with mean durations of 3.33 ± 0.33, 3.00 ± 0.00, 3.00 ± 0.57 and 4.67 ± 0.33 days for the first, second, third and fourth instars, respectively. The total nymphal period was 14.00 ± 0.57 days, adult longevity was 6.00 ± 0.00 days and the total life cycle ranged from 19 to 21 days, with a mean of 20.00 ± 0.57 days. Imidacloprid 17.8 SL was the most effective treatment, providing 61.84% and 62.26% reductions in aphid colonies after the first and second sprays, respectively. Crofton weed leaf extract was the least effective, with 38.32% and 37.72% reductions, respectively.
Conclusion: The study confirms that E. lanigerum completes four nymphal instars under laboratory conditions. Among the evaluated treatments, imidacloprid 17.8 SL showed the highest efficacy against woolly apple aphid under mid-hill conditions of Garhwal Himalaya.
Keywords: Eriosoma lanigerum, woolly apple aphid, apple, developmental biology, nymphal instars, life cycle, pest management, imidacloprid, biorational treatments, Garhwal Himalaya