OCCURANCE AND SEASONALITY OF STREPSICRATES SEMICANELLA AND HELOPELTIS THEIVORA ON EUCALYPTUS AND EFECT OF TEMPERATURE ON THEIR INCIDENCE

Leafroller, Strepsicrates semicanella and the sap sucking bug, Helopeltis theivora caused severe damage on early growth in Eucalyptus (Myrtaceae) trees in Indonesia. However, information on the occurrence, seasonality and effect of weather parameters on these serious pests of Eucalyptus were insufficient. In this study, incidence progression of S. semicanella and H. theivora on Eucalyptus plants after planting was investigated and the damage caused on Eucalyptus plantations was monitored for the period of two years (2018–2020). The ideal phase for S. semicanella to cause considerable damage to young Eucalyptus plantations was one to three months after planting whereas for H. theivora it was three to six months. Incidence of S. semicanella was at peak in May to July and H. theivora was at peak in December to March. There was marginally significant correlation between the incidence of H. theivora and total rainfall (R² = 0.12, P = 0.019) in the same month. The results from the study provided precise estimates in the period of incidence of S. semicanella and H. theivora on Eucalyptus trees and will enhance the strategies to manage both of these pests.