Studies on population dynamics of Helicoverpa armigera and Melanagromyza obtusa in pigeon pea
Kapil Kumar Soni, Akhilesh Kumar, Prakhar Srivastava, Pushpendra Singh Sahu and Hadi Husain Khan
Population dynamics of two important insects of Pigeonpea belonging to the order Lepidoptera i.ePigeonpea pod borer, Helicoverpa armigeraand Diptera order i.e Pigeonpea pod fly, Melanagromyza obtusa was studied in Pigeonpea under the condition of Rewa district during the Kharif 2016 -2017. Studies conducted on the population dynamics of Pigeonpea pod borer in the agro climatic condition of Rewa region indicated its incidence from 1st week of October 2016 to 4th week of December 2016. The initial average population of 0.13 pigeonpea pod borer per five plants/week and 0.72 per five plants was recorded in the month of October 2016 which rose to 0.44 to 0.79 pigeonpea pod borer per five plants/week and 0.61 pigeonpea pod borer per five plants in the month of November 2016. The peak of the population was recorded in the fourth week of October 2016. There after the population of the pest started decreasing gradually and mostly disappeared in the 1st week of January, 2017. Studies conducted on the population dynamics of Pigeonpea pod fly in the agro climatic condition of Rewa region indicated its incidence from 4th week of October 2016 to 4th week of December 2016. Pigeonpea pod fly infestation was noted late in the Kharif season and also its sequence among defoliating insects marked as a late comer but continued to persist up to harvesting of the crop. The initial average maggot population of 0.10 larvae/ 4th week and 0.06 maggot/10 pods/month was recorded in the month of October 2016 which rose to 0.10 to 0.67 maggot/10 pods/week and 0.36 maggot/10 pods in the month of November 2016 which gradual increased up to 49th week (Dec. 1st week 2016) the number of the maggots in per 10 pods was recorded between 0.03 to 1.2 maggots/week with an average of 0.70 maggot/10 pods/ in the month of December 2016.