Données bio-écologiques sur deux espèces jumelles sympatriques en milieux agricoles : Oulema melanopus (L.) et Oulema duftschmidi (Redtenbacher) (Coleoptera, Chrysomelidae)

Abstract

Bio-ecological data on two sympatric sibling species in arable crops : Oulema melanopus (L.) and O. duftschmidi (Redtenbacher) (Coleoptera, Chrysomelidae). A trapping campaign, using Malaise and cornet traps, was carried out in arable crops in the Beauce area (District of Erceville, Department of Loiret) and in the Gâtinais area (District of Boigneville and Maisse, Department of Essonne). It permits to identify two sympatric sibling species of Leaf beetles : Oulema melanopus and O. duftschmidi. Both species represent a potential pest in cereal fields. 4,309 individuals were collected and studied. The results show that there are more females than males (sex ratio of 0.63) catched with interception traps. Among males, 67.7 % belong to O. duftschmidi and 32.3 % belong to O. melanopus. Furthermore, regular captures indicate that the two species have a completely similar flight activity between the end of April and mid-October.