Beetle Communities of Alfalfa (Medicago sativa L.) in the Republic of Moldova

摘要

This article reports on the beetle diversity and abundance study conducted during 2009 and 2010 in three alfalfa fields located near Lozova, Ivancea and Trebujeni in the central part of the Republic of Moldova. All insects were collected using pitfall traps and sweeping techniques. In total, 843 beetle specimens were collected, representing 63 species from 49 genera and 12 families. The largest family was Curculionidae, followed by Scarabaeidae, Carabidae, Coccinellidae, Silphidae, Cerambycidae, Dermestidae, Staphylinidae, Tenebrionidae and Trogidae. Weevils (Curculionoidea) also, represented the greatest proportion in terms of number of individuals. During the present study captured beetles from all three localities were compared and Shannon indices were calculated as a measure of diversity within the habitat. The Shannon diversity index has been found maximum (1.035) in Trebujeni, moderate (1.017) in Ivancea and low (0.936) in Lozova. Five of the recorded species are known to feed on alfalfa (Medicago sativa) and cause serious damage in the Republic of Moldova: Sitona lineatus, S. inops, Hypera postica, Protapion trifolii, Subcoccinella vigintiquatuorpunctata. Of these, S. inops is thought to represent the greatest potential threat based on adult abundance at all three sites and the negative impact of this species. A significant number of beetles collected during this study are adventive species associated with forest ecosystems of the Republic of Moldova.