Impact and reliability of weather factors on occurrence of sapota seed borer, Trymalitis margarias Meyrick

Abstract

An investigation on association of seed borer, Trymalitis margarias Meyrick infestation with ecological parameters was carried out in sapota between 2016 to 2019. Seed borer incidence commenced from September (1.00–1200%) and the peak activity was reported during December (8.50 to 9.25%) at initial fruiting phase. The fruit damage slightly decline in January and again attained maximum in March (10.75%) and April (10.50%) at advance fruiting stage and negligible in July and August. The linear coefficient correlation data revealed that seed borer caused higher damage due to raise of bright sunshine hrs and evaporation as well as by lesser of minimum temperature, morning-evening relative humidity along with absence of rainfall and rainy days equally under preceding and current circumstances. The fruit damage persuades with higher number days comprising <15 °C temperature, <50% relative humidity and > 6 h bright sunshine light along with lesser number days having >80% relative humidity. The regression equations showed variability between 72 to 93% under eight weather parameters with significant impact of minimum temperature, morning and evening relative humidity, evaporation and rainfall on alternate years and had impact on seed borer succession. There was no major deviation in observed and predicted incidence except at early and ending fruiting phase.