Abstract We record for the first time the Darwin wasp species Photocryptus nigrosignatus (Kriechbaumer, 1901) parasitizing nests of the solitary wasp Sceliphron fistularium (Dahlbom, 1843) in the Amazonas state, Brazil, and provide new distribution records for them and S. asiaticum (Linnaeus, 1758), the other species registered to Brazil. Additionally, we also report the emergence of solitary wasp Pachodynerus nasidens Latreille, 1817 (Vespidae), and parasitoid wasps Leucospis sp. (Leucospidae) and Photocryptus sp. in S. fistularium nests.

Resumen Registramos por primera vez a la avispa de Darwin Photocryptus nigrosignatus (Kriechbaumer, 1901) parasitando nidos de la avispa solitaria Sceliphron fistularium (Dahlbom, 1843) en el estado de Amazonas, Brasil, y proporcionamos nuevos registros de distribución para ellas y S. asiaticum (Linnaeus, 1758), la otra especie registrada en Brasil. Adicionalmente, también reportamos la emergencia de la avispa solitaria Pachodynerus nasidens Latreille, 1817 (Vespidae), y las avispas parasitoides Leucospis sp. (Leucospidae) y Photocryptus sp. en nidos de S. fistularium.

RESUMO Pesquisamos vespas parasitoides (Hymenoptera) em duas plantações de guaraná na Amazônia central brasileira (uma convencional e outra manejada organicamente), bem como em florestas adjacentes e áreas de borda entre cultivo e floresta. Avaliamos as diferenças entre os sistemas de manejo na diversidade e abundância de parasitoides e a importância da matriz circundante como fonte de vespas parasitoides para o cultivo de guaraná. A riqueza de vespas parasitoides, abundância e a composição taxonômica (em nível de família) foram comparadas entre as plantações e entre os habitats nas plantações. As vespas foram amostradas usando armadilhas Malaise e Moericke. Foram coletadas 25.951 vespas parasitoides (10.828 em área de cultivo convencional e 15.123 em cultivo orgânico), distribuídas em 11 superfamílias e 38 famílias. Na área de manejo convencional, a maior abundância e riqueza de parasitoides foi registrada na floresta adjacente, enquanto na área de manejo orgânico, a maior abundância e riqueza foram registradas na borda da floresta. A riqueza de famílias de vespas parasitoides não foi influenciada pelo sistema de manejo e habitat, mas variou significativamente entre os tipos de armadilhas. A abundância média de vespas variou significativamente entre os sistemas de manejo. A presença de floresta adjacente em ambas as áreas de cultivo provavelmente contribuiu para uma maior abundância e riqueza de vespas parasitoides, mostrando a importância de preservar as áreas florestais próximas às plantações.

ABSTRACT 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.

Records about stingless bee-fungi interaction are very rare. In Brazilian Amazonia, workers of Trigona crassipes (Fabricius, 1793) and Trigona fulviventris Guérin, 1835 visiting two stinkhorn species, Dictyophora sp. and Phallus sp., respectively, were observed. The workers licked the fungi gleba, a mucilaginous mass of spores covering the pileum. Neither gleba residue nor spores were found on the body surface of these bee workers. These observations indicate that these bee species include spores as a complement in their diet. On the other hand, they also suggest that these stingless bees can, at times, facilitale spore dispersal, in case intact spores are eliminated with the feces.

Stingless bees were collected between 1984 and 1990 in continuous forest, forest fragments and cleared areas 90 Km north of Manaus, Amazonas, Brazil. Several methods were employed. a total of 54 species of 21 genera were collected including two undescribed species of Plebeia Schwarz, 1938. The most abundant genera were Trigona Jurine, 1807; Melipona Illiger, 1806; Partamona Schwarz, 1939 and Tetragona Lepeletier, 1825. The most abundant species were Trigona crassipes (Fabricius, 1793) and T. fulviventris Guérin, 1835. Fruit fly traps baited with fragrances for euglossine bees showed to be an useful method for stingless bee collection too. The study area showed a great richness in relation to other regions of the world. However the density of nests found from a 100ha area of continuous forest were low (1 nest/6.67ha). The consequences of deforestation on stingless bees populations and of the decrease of these on the forest conservation are also discussed.