Studies on genetic variability of predatory stink bug (Eocanthecona furcellata Wolff) in Kumaon region of Uttarakhand
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Date
2018-06
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G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
The present investigations were carried out during 2017-18 at various locations in Kumaon region of Uttarakhand and laboratory studies were done in Bicontrol laboratory, Department of Entomology, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar. Results of the study of distribution and host range of Eocanthecona furcellata in Kumaon region reveal that the preferred host of this predatory bug in the region are Amaranthus leaf eating caterpillar (Hymenia recurvalis), Wheat army (Mythimna separata), Tobacco caterpillar (Spodoptera litura), Spotted pod borer (Maruca
vitrata), Poplar defoliator (Clostera fulgurita), Gram pod borer (Helicoverpa armigera) and Rice leaf folder (Cnaphlocrosis medinalis). Study of biology of various strains of the predatory stink bug, E. furcellata on rice meal moth, Corcyra cephalonica, revealed that incubation period varied from 6.33±0.57 days to 7.00±1.00 days. Total nymphal period varied from 24.33±1.32 to 27.00±1.83 days. Adult longevity ranged from 13.00±1.00 to 16.67±1.52 days. Study on predatory efficiency revealed that first nymphal instar fed on plant sap. Feeding on C. cephalonica larvae started from second instar. The rate of predation in the nymphal instar varied from 69.86 to 88.6 per cent; in adults it varied from 69 to 75.71 per cent. The variation in the mean predation rate was from 74.89 to 79.28 per cent. The results of the study of genetic variability of E. furcellata in Kumaon region reveal that the strain of the predatory bug from high hills was found to be particularly distant (07% similarity) from the strains belonging to mid hills, valley region and tarai region. Hence, it was concluded that E. furcellata is widely distributed in Kumaon region and feeds on a wide range of hosts. There was no significant change in the biology and predatory efficiency of the predator with change in geographical and climatic conditions of the habitat, even in genetically diverse strains. This suggests that the predator has adapted itself (genetic diversity) to survive the extreme climatic conditions but has still maintained its biological attributes. So, the use of local strains of the predators in the biological control programs is recommended.
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