PRELIMINARY OBSERVATIONS ON THE PEAR ROOT BEETLE, XYLEBORINUS SAXESENI RATZ. (COLEOPTERA: SCOLYTIDAE)

Xyleborinus saxe >eni Ratz. beetle infests the trunk and branches of apple. apricot, pecan, plum, casuarina, oak, poplar, walnut and willow trees. The present study detected that this beetle also infests pear tree roots in several orchards in different governorates. The relative preference of X.saxeseni to different hosts differed according to the host type, highest percentage of entrance holes re‌corded on plum and pear (26% and 25%, respectively), the lowest per‌centage was on peach (1%). while citrus was entirety free of infestation. The ability of PRB to penetrate through the soil to infests the pear roots decrease with increase the soil thickness. Seasonal abundance revealed that the beetle was abundant dur‌ing the whole year round, five peaks were observed at the 1st half of May, 2nd half of June, 1st half of August, 2nd half of september and 2nd half of November.