An Invasive Species: Leptoglossus occidentalis (Heidemann) How Does It Affect Forestry Activities?

Abstract

Aim of study: Leptoglossus occidentalis which is first identified by Heidemann at North America in 1910 spread quickly after WW II. Although it was first seen in 1999 in Europe has swept the continent in 10 years. First damage observation in Turkey reported in Kozak Basin of Bergama on cones of stone pine trees which has valuable edible seeds. The seed yield loss started in 2005 and reached to a peak in 2009. In addition to high early age conelet loss, rate of emptiness of cones has sometimes reached to 90 %. The bug causes decrement in seed formation and seed germination ability significantly by causing early stage conelet loss and destroying endosperm parts of mature cones. In respect of forestry activities decrement of seed resources caused due to bug damage will have negative impact on natural regeneration activities in Turkey and probably will end in failure. In this study, it was aimed to determine the severity of damage caused by the collecting of cone samples from the stone pine forests in our country. Area of study : Without making any discrimination either planted or natural or any altitude or any aspect, stone pine cones have been collected from 42 localities which are distributed all around Turkey. Material and Methods: Weight and size of cones have been measured and seeds extracted by holding at 55 0 C in climate cabinet, then damage on seeds of L. occidentalis and unshelled seed yield determined. Main results: Empty seed formation in stone pine cones varies between %14 and 98%, depending on the region. There is no difference between natural or plantation forests in terms of empty seed formation. Research highlights: All necessary control strategies should be developed against this bug which has high potential as technic and cost for affecting forestry.