Historical Biofix table for blog

Historical biofix dates for three moth pests of tree fruit at the Winchester AREC

Biofix is the calendar date on which the first sustained capture of insects from the overwintering generation occurs. At the Winchester research center, we establish biofix for three key moth pests of peaches and/or apples, 1) oriental fruit moth, 2) codling moth, and 3) tufted apple budmoth. Prior to moth emergence and flight each spring,  three pheromone-baited traps for each species are deployed in our orchards and captures are recorded daily. When at least two traps capture new moths over at least three consecutive evenings, biofix is set as the first day on which sustained captures occurred. Starting on the biofix date, daily heat until accumulations (“degree-days” or “DD”) are calculated based on developmental threshold temperatures for each species. Accumulated degree-days are used with models that predict the rate of development of eggs and larval hatch for each species. Critical points in the development of each generation of each species are predicted by the model, so that growers can time their control measures optimally. In combination, determining the biofix date and initiating degree-day models from biofix each year enable best management practices regardless of annual variations in environmental conditions that affect pest emergence and developmental rate. The accompanying table illustrates annual variations in biofix dates at the Winchester research center since 2000.