Influence of different plant genotypes on some biological parameters of cotton mealybug, Phenacoccus solenopsis and its predator, Coccinella septempunctata under laboratory conditions.
Muhammad Sana-Ullah, Arif M. J., Gogi M. D., Shahid M. R., Adid A. M., Ali Raza, Asif Ali
Author Affiliation: Department of Agri. Entomology, University of Agriculture, Faisalabad, Pakistan.
International Journal of Agriculture and Biology 13 : 125-129
Abstract : The response of different plant species on some biological parameters of cotton mealybug and of its predator Coccinella septempunctata was investigated. All the tested plant species affected the studied biological parameters of cotton mealybug and C. septempunctata significantly. Maximum mortality in 1st instar nymphs (70-90%) was induced by rose (Rosa indica), jatropha (Jatropha curcus), mango (Mangifera indica), ashoke plant (Saraca indica), niazboo (Ocimum basilicum) and bouginvilla (Bougainvillea spp.); in 2nd instar nymphs (50 to 70%), by rose, jatropha, mango, niazboo and Ficus sp., and in 3rd instar nymphs (40-50%) by ficus, rose, jatropha and bakain. The nymphal duration was prolonged by 20-23 days, when nymphs were fed on rose, jatropha, mango, ashoke plant, niazboo, Ficus and bakain, the same was shortened (16-17 days), when nymphs were fed on peeple, gardenia, shesham, Janem, vincarosa, cotton, shoeflower and silvery. The least fecundity in cotton mealybug was recorded for rose and jatropha (100-200 eggs/ovisac/female), while it was the maximum in case of shoeflower (>400 eggs/ovisac/female). Sterculia, niazboo, mango, ficus, rose, ashok, bakain, bouginvilla and jatropha caused maximum mortality (61-80%) in the adults of C. septempunctata. Life duration of C. septempunctata shortened (7-12 days) in case of sterculia, niazboo, mango, Ficus sp., rose, ashok, bakain, and bouginvilla; whereas the same was prolonged the most (16-18 days) in case of lantana, itsit, shoeflower and cotton. Sterculia, niazboo and mango, ficus, rose, ashok and bakain badly affected the consumption of C. septempunctata (approximately 50-70% reduction in consumption). The consumption by C. septempunctata increased by 81-90% of the offered nymphs (10-20% reduction in consumption) in case of lantana, itsit, shoeflower and cotton as host plants of the prey insect. It was concluded that the host plants influenced the biology of insect pest and its predator. However, the biochemical factors influence the biology of both prey and its host need to be explored.