Diversity of wasps (Hymenoptera: Vespidae) in conventional and organic guarana (Paullinia cupana var. sorbilis) crops in the Brazilian Amazon. The present study aimed to determine the diversity of wasp species associated with the guaraná crop and the difference in composition of species associated to organic and conventional crops, as well as among environments established in each management (adjacent forest, crop edge and guaraná crop). We collected 977 individuals and 59 species, in 23 genera of Vespidae, sixteen of Polistinae (52 species) and seven Eumeninae (seven species). Polybia was the most abundant and rich genus with 553 specimens and 15 species, followed by Agelaia (139, nine) and Protopolybia (103, five). In organic management crop, 686 individuals allocated in 18 genera and 47 species were collected, whereas in conventional management crop 291 individuals allocated in 18 genera and 41 species were collected. According to the three sampling points, in both management types, the edge of the crop field shows the highest abundance of wasps with a total of 519 individuals allocated in 19 genera and 45 species. Given the intense use of both environments (forest and crop) by the wasps, it is important to grow crops in regions near native forests, where the chances of social wasp colonies to be founded are increased.

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A new species of Horismenus Walker, H. liturgusae Hansson & Schoeninger (Hymenoptera: Eulophidae), is described from material reared from an ootheca of an unidentified mantid species of genus Liturgusa Saussure (Mantodea: Liturgusidae). The new species is compared to H. argus Hansson, a species it is very similar to. Horismenus liturgusae sp. n. is gregarious and 49 adult specimens developed in the ootheca. This is the first record of a Horismenus species parasitizing mantids, and the first record of a Horismenus species from an ootheca.

We surveyed parasitoid wasps (Hymenoptera) in two guarana plantations in the central Brazilian Amazon (one conventionally, and one organically managed), as well as in adjacent forest and edge areas between crop and forest. We evaluated differences between management systems in parasitoid diversity and abundance, and assessed the importance of the surrounding matrix as a source of parasitoid wasps for guarana cultivation. Parasitoid wasp richness, abundance and taxonomic composition (at family level) were compared between plantations, and among habitats within plantations. Wasps were sampled using Malaise and Moericke traps. A total of 25,951 parasitoid wasps (10,828 in the conventional, and 15,123 in the organic crop area) were collected, and were distributed in 11 superfamilies and 38 families. In the conventional management area, the greatest abundance and richness of parasitoids were recorded in the adjacent forest, while, in the organic management area, the greatest abundance and richness were recorded in the crop-forest edge. Parasitoid wasp family richness was not influenced by management system and habitat but varied significantly between trap types. Average wasp abundance varied significantly between management systems. The presence of adjacent forest in both cultivation areas likely contributed to a greater abundance and richness of parasitoid wasps, showing the importance of preserving forest areas near the plantations.

RESUMO O objetivo deste trabalho foi realizar o levantamento das famílias de himenópteros parasitoides associados ao cultivo do tabaco (Nicotiana tabacum L) no Estado do Rio Grande do Sul. Foram realizadas coletas quinzenais com armadilhas de Malaise, pitfalls e bandejas amarelas em lavouras de tabaco nos municípios de Santa Cruz do Sul e Lagoão. Durante o período de novembro de 2007 a fevereiro de 2008, foram coletados 1.047 indivíduos da ordem Hymenoptera. Destes, 738 parasitoides estão distribuídos em 23 famílias. Ichneumonidae, Braconidae e Scelionidae foram as famílias mais abundantes, representando 44,6%, 14,9% e 11,5% dos indivíduos parasitoides coletados, respectivamente.