Prediction of the flight of Hyalesthes obsoletus, vector of stolbur phytoplasma, using temperature sums

A method to predict the flight of the planthopper Hyalesthes obsoletus, the vector of stolbur-phytoplasma that causes Bois noir disease in grapevine, is presented. The parameters required for the calculation of temperature sums were determined by multiple calculations of temperature sums till the observed dates of the start of flight activity of adult planthoppers in different years and the identification of combinations of starting dates and temperature thresholds for day-degree accumulation that led to a minimum relative standard error. The method can be currently used for populations of H. obsoletus that live on bindweed (Convolvulus arvensis), only. It needs to be adjusted for populations on nettle (Urtica dioica) that show a different flight activity. The procedure described here could be useful for other insects, too, where relevant data of the life cycle cannot be determined in laboratory rearing.