Estimating the level of fruit scarring by citrus thrips from temperature conditions prior to the end of bloom

Abstract

In this study, we develop and validate multiple regression models to estimate the degree of fruit scarring by citrus thrips, Scirtothrips citri (Moulton), from heat and chill degree days. Regression coefficients indicate that cool weather during early March (2 March–16 March) and warm weather during bloom are associated with high levels of thrips scarring. The biological mechanisms leading to the temperature-fruit scarring relationships are unknown. An economic analysis suggests that using model predictions may increase the average financial return per hectare and reduce the number of insecticide treatments applied against citrus thrips.