Population Dynamics of Aphid and Pod Borer on Lentil and their Natural Enemies during rabi Season 2017 at Pusa, Samastipur

摘要

In order to determine the seasonal incidence and to explore the possibilities of management of aphid and pod borer on lentil through various tactics, a series of field experiments were conducted at Research Farm of Tirhut College of Agriculture, Dholi, Muzaffarpur, The incidence of aphid ( Aphis craccivora ), ?started from 4~(th) meteorological standard week (MSW) (23.80 aphid/10 cm apical twigs). The aphid population gradually increased and reached to its peak (35.4 aphid/10cm apical twigs) on 7~(th) MSW (22~(nd) February) and thereafter its population gradually decreased from 8~(th) MSW 4~(th )?week of February (31.30 aphid/10 cm apical twigs) to 12~(th) MSW(4~(th )?week of March) (9.0 aphid/10cm apical twigs). The incidence of pod borer ( Etiella zinckenella )? was observed from 7~(th) MSW(3~(rd) week of February) (4.00%) and the per cent pod damage gradually increased and reached to its peak (14.30 %) on 9~(th) MSW (~(1st) week of march). Its infestation gradually decrease 10~(th) MSW (12.10 %) onwards. Initially Coccinella. septempunctata ?? population was very low in 4~(th )MSW of January, 2018 (0.90/plant) and after that the population gradually increased. The maximum population of C. septempunctata (4.50/plant) was recorded in 8~(th) MSW of February, 2018. Spider population was very low (1.10 spider/plant) in 4~(th) MSW of January, 2018 and the maximum population (2.00 spider/plant)of spider was recorded in 6~(th) SMW of February.