Degree-Day Forecasting Method: A Tool for Increasing the Precision of Chemical Control for Managing Peach Flat-Headed Borer, Sphenoptera dadkhani

Studies were conducted to develop an IPM plan for the control of peach flat-headed borer using degree-day forecasting to predict the adult emergence time of the borer and thus determine the proper time for initiating the chemical control measures. Adult emergence in the observed years started in the first week of April with a degree-day (DD) accumulation of 567-573 and continued upto the first week of May. Cumulative degree-day (CDD) summations to first emergence in the second generation ranged from 2355-2374 and lasted till the second week of August. Third generation emergence was observed when 4545-4580 DD were accumulated. A difference of 5-15 days in the start of emergence for all the three generations was observed. Similarly, for peak emergence, a difference of more than one month was observed during the study years. CDD calculations, on the other hand could be translated into a difference of 1-3 calendar days. Thus DD can be used as an accurate predictor for initiating the control measures that can lead to precise control of the pest. Trials conducted to evaluate the efficacy of different insecticides indicated that all the tested insecticides significantly controlled the adult population. A single spray of Confidor or Ematac at the time of first adult emergence (when 570 DD were accumulated) was very effective and reduced the adult population by more than 85%.