Study on the Bio ecology of Psalmocharis alhageos (Kol.) in the Field Conditions in Malayer

In this study, two grape orchards infected by vine cicada were selected in Baba-raees and Mishen villages of Malayer, with different soil structure and an uninfected one in Malayer station. The biology of the pest studied by encaging 15 grape trees in the uninfected orchard and releasing five mature male and females of the vine cicada in each cage. The developmental stages of the insect thus onset and the peak of emerging nymphs, the trends of population fluctuation and infection rate were determined observing exuviae and emerging holes. The adult longevity was 11 days and the hatching duration of eggs was about one month. The adult cicadas flied late June to late August and the nymphs were emerged from the soil late August. Compared to the orchards with relatively heavy texture, the severity of infection was higher in orchards with relatively light texture soil. It was found that the peak of the nymph emergence was happened when both air and soil temperatures at the depth of 30 cm, reached to maximum of, 34°C. Moreover, the onset and peak of the nymph emergence Occurred when 408 and 1342 Growth Degree Day (GDD) was accumulated for vine trees respectively. In addition, the peak had a negative and a positive correlation with relative humidity and evaporation, respectively. Furthermore, the rate of egg parasitism was 1.16% and 0.78% in Baba-raees and Mishen respectively.