Diversity and habitat preferences of Carabidae and Staphylinidae (Coleoptera) in two agroecosystems

Abstract

The present study had as objective determine the diversity and abundance of adults Carabidae and Staphylinidae in two areas, constituted by forest fragment and soybean/corn crops under conventional tillage and no-tillage systems and to analyze the distribution and preference of those beetles for the habitat. The beetles were sampled with 48 pitfall traps. In both experimental areas, two parallel transects of pitfall traps were installed. Each transect had 100 m in the crop and 100 m in the forest fragment. Four traps were close to each other (1 m) in the edge between the crop and the forest fragment, the other traps were installed each 10 m. The obtained data were submitted to the faunistic analysis and the preference of the species by habitat was obtained by cluster analysis. The results demonstrated that the type of crop system (conventional tillage or no-tillage) might have influenced the diversity of species of Carabidae and Staphylinidae. The cluster analysis evidenced that the carabids may prefer a specific habitat. In the present study, the distribution of carabids and staphylinids in the three habitats showed that these beetles have potential to be dispersed at great distances inside the crop.Key words: ground beetles, rove beetles, no-tillage systems, forest fragment, edge.Diversidade e preferência de habitat de Carabidae e Staphylinidae (Coleoptera) em dois agroecossistemas ResumoEste estudo teve como objetivo determinar a diversidade e abundância de adultos de Carabidae e Staphylinidae em duas áreas, constituídas por fragmentos florestais e culturas de soja/milho sob sistemas de plantio convencional e direto, e analisar a distribuição e a preferência desses insetos para o habitat. Os besouros foram amostrados com o uso de 48 armadilhas de solo do tipo Pitfall. Em ambas as áreas experimentais, foram instalados dois transectos paralelos de armadilhas; cada transecto teve 100 m na culturas e 100 m no fragmento florestal. Na borda entre a cultura e o fragmento de floresta foram instaladas quatro armadilhas, que ficaram distantes entre si por 1 m e as outras armadilhas, a cada 10 m. Os dados obtidos foram submetidos à análise faunística e a preferência das espécies para o habitat foi obtida pela análise cluster. Pelos resultados, observa-se que o tipo de sistema de cultivo (convencional ou plantio direto) pode ter influenciado a diversidade de espécies de Carabidae e Staphylinidae. A análise de cluster evidenciou que os carabídeos tiveram preferência por um habitat específico. Neste estudo, a distribuição de carabídeos e estafilinídeos nos três habitats mostraram que estes besouros têm potencial para se dispersarem em grandes distâncias no interior da cultura.Palavras-chave: Carabídeos, estafilinídeos, sistemas de plantio direto, fragmento florestal, borda.

Occurrence of Carabid Beetles in the Phenological Stages of Weedy Plants

“…By contrast, the presence of C. granulatum, G. brasiliensis, and O. nodicornis in the edge habitats suggests that these habitats act as temporary refuges for these species [32] [33]. This is also supported by reports that C. granulatum prefers soybean/corn crops and is rarely observed in forest fragments and that O. nodicornis behaves as a forest species [19], whereas G. brasiliensis occurs mainly in corn crops rather than in rubber tree plantations (Hevea brasiliensis Muell Arg) or soybean crops [34].…”

“…Traps were 500-ml (80-mm diameter) plastic cups filled with a solution of formaldehyde in water (1%) and detergent [19] [21]. To install each trap, a hole was dug and a plastic cup was inserted so that the lip of each cup was level with the ground.…”

“…Despite the rich carabid fauna in Brazilian agroecosystems [18] [19], there are no specific studies from this region on carabid beetles as weed seed consumers or on their relationship with the phenological stages of weedy plants. The only studies published on the feeding habits of Brazilian carabids were by Barbosa et al [20], who evaluated the effect of different diet types on biological aspects of two carabid species, and Matta et al [21], who determined the types of food within the digestive tract of carabids associated with herbaceous plants and colored cotton.…”

Comparison of beat cloth and entomological net methods for determining faunistic indices of soybean in Rio Grande do Sul, Brazil

“…Richness and dominance (indices that measure the number of species per point) are different in terms of altitude, when entomological net is used, because this method captures a larger number of species. Regarding different environments, no-till areas and large forest fragments have higher diversity of Carabidae and Staphylinidae species compared with areas under conventional tillage (Martins et al, 2012); thus, the environment can influence faunistic indices.…”

“…Estimates of faunistic indices provide information on distribution, richness and abundance of species within a community. The advantage of such indices is that they generate analyzable data, and by definition, they are devoid of unity, allowing comparisons between communities sampled with a nonstandard method (Wade et al, 2006;Haddad et al, 2011;Martins et al, 2012). Therefore, studies on the diversity of beneficial and pest insects have been performed in different crops (Wade et al, 2006;Stürmer et al, 2012).…”