ACTIVITY OF PEACH TWIG BORER Anarsia lineatella Zeller AND ITS ASSOCIATED BIO AGENTS ON PEACH TREES

Abstract

The seasonal activity of the peach twig borer, Anarsia lineatella Zeller was in-vestigated during 2004 and 2005 seasons. The data revealed that the infested twigs empty from larvae (15%) were higher than that with larvae (1.25%) in February. The situation was reverse in April which recorded 8% and 14.75% for both, respec-tively. In fruits, infestation began to appear in the third week of March which rec-orded 2% whereas the maximum rate was recorded in May (16.75%). Three species of hymenopterous parasitoids were found; Apanteles ruficrus Haliday (Fam. Braco-nidae), Diplazon laetatorus Fab. (Fam. Ichneumonidae) and Microgaster tiro Rein-hard (Fam. Braconidae). These parasitoids reached its maximum during April (13.5%) that seems to be more active. Their numbers were positively correlated with the rate of infestation (r = + 0.799). In spite of presence of four predatory species (Coccinella undecimpunctata L., Rodalia cardinalis Mulsant, and Scymnus syriacus Marseul (Coleoptera: Coccinellidae) and Syrphus sp. (Diptera: Syrphidae)), it seems to be less active. Their numbers recorded very slight positive correlation with the rate of infestation (r =+0.423)