Reporting Olive bark midge Resseliella oleisuga Targ. (Diptera: Cecidomyiidae) infesting olive trees in North Palestine.

Abstract

Olives as one of the most spread tree over Palestinian territories is considered as the mainstay of rainfed agriculture in Palestine. Recently and due to global warming effect, the trees exhibited an outbreak of many pests and pathogens. In the last decades olive fruit trees and pea cock eyespots reported unusual percentage of infection over olives. During this year (2016), and throughout the field surveys for investigation of any unusual diseased symptoms on olives; some trees exhibited pale yellowing on the newly formed branches, symptoms associated with viral infections such as OLYaV. Some other trees were noticed to get yellowing and later on developed branch dieback and stem canker and cracking syndromes. These symptoms were observed on both young and old trees in northern part of Palestine. Laboratory investigation for detection of viral diseases still in its way, but notably founding was the heavy infestation of larvae which were backed inside branch cracks. Larvae were incubated in vitro and the molted pupa had given flies identified as Resseliellaoleisuga (CLINOL) that belonging to the family Cecidomyiidae. The incidence of infestation is undergoing research. Correlation with viral infections still unrevealed yet. The believed of the climate changes due to global warming might be the cause of their outbreaks is much plausible due to ensuring the suitable environment conditions for the insect to be grow and spread on olives in Palestinian territories. For our knowledge, this is the first time this insect was reported to be widely spread on olive trees and causing damages in Palestine.