Population dynamics of chiku moth, Nephopteryx eugraphella (Ragonot) in relation to weather parameters

Abstract

The present investigation was carried out to study population dynamics of Nephopteryx eugraphella (Ragonot) in relation to weather parameters at the Horticultural Farm, B. A. College of Agriculture, AAU, Anand during 2014-15. The results showed that the infestation of chiku moth was appeared more or less throughout the year. The population of chiku moth, per cent leaf and bud damage were found in the range of 0.00 to 8.90 larvae per twig, 7.85 to 44.01% and 0.00 to 7.98%, respectively. The incidence of N. eugraphella on sapota was found during 3rd week of November (46th SMW) to 1st week of May (18th SMW) and 3rd week of May (20th SMW) to 2nd week of November (45th SMW). The activity of this pest reached at peak during 1st week of August, 31th SMW (8.90 larvae per twig and 44.01 per cent leaf damage) to 3rd week of September (38th SMW). The higher incidence was noticed during 4th week of July (30th SMW) to 1st week of November (44th SMW) which reflected on leaf as well as bud damage. The wind speed had significantly positive correlation (r = 0.277*) with larval population. The morning relative humidity, evening relative humidity, morning vapour pressure, evening vapour pressure and minimum temperature had highly significant positive effect on the larval population of this pest. The bright sunshine hours and evening vapour pressure deficit had highly significantly negative correlation (r = -0.589** and r = -0.440**, respectively) with larval population of chiku moth.