Quantifing Diversity and Phenology of Cereal Leaf Beetles Oulema Spp. (Chrysomelidae: Criocerinae) in Several Cereal Fields of Semi-Arid Zone, Algeria

Abstract

The present study treated the taxonomic diversity of the cereal leaf beetle (Oulema spp.) community subservient to several cereal fields (barley, durum wheat and oats) in Eastern Algeria. From April to June, which is the appearance period of these insects, the leaf beetle fauna was weekly sampled using two trapping techniques: entomological net and sight hunting method. Spatiotemporal alpha and beta diversity of this community were evaluated by several ecological indices: Shannon index, Simpson index and equitability. The multivariate statistic test (GLM) was used to assess the variation of the different diversity parameters. Catches totaled 1144 individuals belonging to the genus Oulema and four species: Oulema melanopus, Oulema cyanella, Oulema duftscmidi and Oulema gallaeciana. The highest abundance of the leaf beetles was recorded in oats with 569 individuals (49.73%), followed by barley (390 individuals, 34.09%) and durum wheat (185 individuals, 16.17%), whereas the most speciose field was barley (4 species), followed by oats (3 species) and durum wheat (2 species). The most abundant species was O. melanopus with 746 individuals (65.20% of the total). The spectrum of occurrence ranked constant species first, followed by common and very accidental species. GLMs demonstrated that diversity of cereal leaf beetles Oulema spp is highly related to cereal field type.