Effect of weather parameters on sporadic incidence of cucumber moth, Diaphania indica (Saunders) (Lepidoptera: Pyralidae) in bitter gourd ecosystem

The field experiments were carried out to study the population fluctuation of Cucumber moth, Diaphania indica in bitter gourd and its relationship with different weather variables during Kharif seasons of 2014 and 2015 in Varanasi region. Weekly data on larval population of D. indica on bitter gourd were taken through simple random sampling whereas different abiotic parameters were obtained from the meteorological observatory of the institute. The results revealed that the D. indica population commencedfrom 31st SMW. The maximum population was recorded during 38th SMW (in 2014), during 39th SMW (in 2015). During September in both the years. The maximum, minimum and mean temperature, growing degree day, heliothermal unit and evaporation rate showed significant positive correlations with this sporadic pest where as a negative correlation was established with relative humidity, rainfall and wind velocity. A weather based prediction model has also been developed with different weather indices and pest incidence using weekly average value.