دراسة حقلية ومعملية لدورة حياة حشرة سوسة سنابل الحبوب

Abstract

The objective of this study is to determine the apperance time and the life cycle of wheat spike weevil Pachtychius hordei (Brulle) Coleobterea, curculionidae in EL-Marj Region in the East of Libya during 2015 to 2016. The study is applied on weeds and Grain crops fields (wheat and barley). By field visiting every two weeks from Mid February to harvesting time (end of May) it also continued after harvesting season. According to the results obtained, P. hordie was distributed on all El-Marj regions on Fam. Graminea (weeds, Barley, Wheat), adults are feeding on leaves, lay one egg in the grain (Lactic stage, 1⁄4th of grain size), the larvae feed on grains then turns ub to free white pupa inside grain , next season emerges as adult, it has one generation per year but some adults have summer dormancy, thos adults stay alive to next season with pale color, then eggs on weeds and wheat and barley remain from the last season and then they invade all the field.the pest have one generation per year and some adults live for tow years.