Vol. 7, Issue 4 (2019)
Surveillance of mirid bug, Poppiocapsidea biseratense (Distant) in Bt cotton
Author(s): Jeer Vinayaka and BS Nandihalli
Abstract: Population fluctuation studies on mirid bug were conducted at Main Agricultural Research Station (MARS), Dharwad, Karnataka, India, during kharif 2016-17 and 2017-18. MRC 7351 (Kanaka) Bt cotton crop was raised under unprotected conditions during the the month of June-July. The pooled data of two years indicated that the activity of mirid bug started with the population of 0.89 bugs/ 5 squares during 36th MSW and steadily increased with a population of 3.03 to 10.50 bugs from 37th to 45th MSW, respectively and reached maximum peak at 46th MSW (12.00). Thereafter the population of bugs started to decreasing trend from 47th to 7th MSW. The damaged squares noticed from 37th MSW with 7.74 per cent and slowly increased from 38th to 43rd standard week with 8.49 to 17.62 per cent damage and reached peak at 48th MSW (23.76%). Thereafter the per cent damage decreased from 49th MSW (19.37) to 8th MSW (0.31). The coccinellids were noticed throughout the season starting from 33rd MSW (0.20/ plant) reaching two peaks at 49th MSW (1.16) and 51st MSW (1.14). The chrysoperla activity commenced from 36th MSW (0.20/plant) with two peaks at 42nd MSW (1.27) and 45th MSW (1.02). Similarly, two peak populations of spiders were noticed at 42nd MSW and 44th MSW (1.34 and 1.60). Weather parameters and natural enemies correlated with the population of mirid bug showed negative association with maximum temperature, minimum temperature and rainfall and showed no significant relationship with mirid bug. Whereas maximum and minimum relative humidity were positively correlated and showed no significant relationship. Chrysoperla (0.823**) and spiders (0.912**) showed highly significant and positive correlation on mean number of mirid bugs while coccinellid (0.380*) showed positive with significant relationship. Weather parameters and natural enemies had an influence to an extent of 85.40 per cent.
Pages: 2258-2262 | 256 Views 69 Downloads
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How to cite this article:
Jeer Vinayaka, BS Nandihalli. Surveillance of mirid bug, Poppiocapsidea biseratense (Distant) in Bt cotton. Int J Chem Stud 2019;7(4):2258-2262.
