Study of partial biological and behavioral traits of Hishimonus phycitis, vector of lime witche's broom, for management of the disease

Witches’ broom disease of lime (WBDL) is a serious threat to lime industry in Iranian southern provinces. Vector identification and transmission characteristics are main factors in epidemiology and management of phytoplasma diseases including WBDL. Investigation of the collected sucking insect fauna on witches’ broom infected lime trees in Hashtbandee, Minab and Roodan (Hormozgan province) using PCR and RFLP assays showed that Hishimonus phycitis leafhopper and Diaphorina citri were positive for 'Ca. Phytoplasma aurantifolia' presence. However, only H. phycitis, previously identified as vector of WBDL, successfully transmitted the phytoplasma to Bakraee (Citrus reticulate hybrid) seedlings and bearing lime trees. Host range studies showed that H. phycitis can reproduce only on citrus and ziziphus species and was unable to reproduce on eggplant, watermelon, alfalfa and carrot, reported hosts of H. phycitis in india. Results of population fluctuation revealed a main peak for the H. phycitis from February to March. However, the lowest population density was observed in warm months (May to October). The population density of vector on healthy and witches’ broom affected trees was compared and the results revealed that the population density of vector was significantly higher on witches’ broom affected trees than healthy ones. It can demonstrate that in affected lime trees, witches’ broom branches can prepare appropriate niche for H. phycitis reproduction. On the basis of the above data, it is possible to predict that cutting of witches’ broom can be an effective approach for reduction of vector population and WBDL management.