Host Selection of Peach Rootborer Capnodis tenebrionis L. (Coleoptera: Buprestidae) to Stone-Fruit Trees in Jordan *)

Abstract

Field and laboratory experiments were conducted during April 2006 to December 2008 to investigate host selection of peach rootborer (PRB) to stone-fruit trees. PRB adults selected significantly peach trees for feeding and oviposition more than apricots and plums, while bitter almonds were the least selected host. Peaches contain lower levels of prunasin than apricots, plums, and almonds. Bitter almond is the only host containing amygdalin (94.0 mg/100g dried sample). When these results were matched with the results of field experiments, it became obvious that peach trees, which have the least prunasin content is more susceptible to infestation by PRB than apricots or plums. Bitter almonds which have amygdalin in the kernels and high prunasin content in the leaves and roots are the most resistance. The Nitrogen content in roots and leaves of bitter almond is significantly higher than the N-content of other hosts. Increased availability of N in almonds lead to increase synthesis of N-containing secondary compounds, such as prunasin and amygdalin, which in turn decrease the susceptibility of stone-fruits to infestation by PRB.