Assembleia de Ichneumonidae (hymenoptera: ichneumonoidea) no cultivo convencional e orgânico de guaraná (paullinia cupana var. sorbilis (mart.) ducke) na Amazônia Brasileira

Abstract

Guarana (Paullinia cupana var. sorbilis (Mart.) Ducke, Sapindaceae) is widely cultivated in the state of Amazonas, with a production that represents 22.6% of the total production of the country. However, there is a lack of basic studies of the fauna associated to the crop, especially hymenoptera parasitoid, that act in the biological control of pests. The objective of this dissertation was to characterize and evaluate the Ichneumonidae (Hymenoptera: Ichneumonoidea) assembly of the vegetation adjacent to the organic and conventional management of guarana (Paullinia cupana) in the Brazilian Amazon. The collections were carried out at EMBRAPA, with the use of Malaise and Moericke traps between September 2012 and February 2013, in an area of conventional cultivation, one of organic cultivation and adjacent vegetation. A faunistic analysis was performed to determine the main groups with the ANAFAU software and the differences of abundance, richness and composition were evaluated with the aid of Software R. 524 Ichneumonidae specimens were collected from 18 subfamilies, 56 genera and 148 species. Fauna analysis revealed the predominance of rare and infrequent genera (54.2% in the conventional and 47.1% in the organic). For abundance, no differences were detected between organic and conventional management and between the variable sampling point. For richness, there was a difference in relation to the sampling point, with the adjacent forest with higher species richness of Ichneumonidae. The Ichneumonidae composition was influenced by the variable management and sampling point of the 148 species, 66 were collected only in the forest, 25 were border exclusive, and 14 species occurred only in the interior. Nine species were recorded at all sampling points. In relation to richness and abundance, the similarities found in both managements may be related to the adjacent vegetation, since the maintenance of the richness and abundance of parasitoids in crops depends on the diversity of the vegetation inside or in its surroundings. Since Ichneumonidae has a wide host diversity, these parasitoids may have migrated to the crop following the hosts. This movement of the hosts possibly resulted in the difference that was observed in the composition of Ichneumonidae species. This study evidenced the high number of rare, infrequent and accidental genera and exposed the predominant groups in each management system. As well as, it reinforces the importance of the maintenance of the native vegetation adjacent to the crops and of more diversified agroecosystems for the conservation of Ichneumonidae species in the Amazon region.