Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?

Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong "numerical" effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative "identity" effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.

Comparação da fenologia e produção de frutos de camu-camu (Myrciaria dubia) entre uma população natural e uma plantação na Amazôniacentral, Brasil / Phenology and fruit set comparison of camu-camu (Myrciaria dubia) in a natural population and a plantation in the central Amazon, Brazil

Myrciaria dubia (Myrtaceae) é um arbusto que produz frutos com altas concentrações de ácido ascórbico (1380 a 1490 mg 100 g-1 na polpa e 2050 mg 100 g-1 na casca), 20 vezes mais que a acerola e 100 vezes mais que o limão. Nativo da região amazônica, ocorre naturalmente em ambientes sazonalmente inundados, nas margens de lagos e rios, mas também é cultivado comercialmente em terra firme. Neste estudo, observações fenológicas e avaliação da produtividade de frutos foram realizadas em uma população natural de camu-camu em ambiente inundável e em uma plantação em terra firme, na Amazônia central. Visitas quinzenais foram feitas durante um ano para coleta de dados sobre floração, frutificação e fenologia foliar. No auge da floração, os botões florais foram marcados e acompanhados até a maturação dos frutos, que foram colhidos para biometria e contagem das sementes. Os frutos variaram de 1,01 a 2,73 cm em diâmetro e 1,14 a 10,87 g em peso, com maior produção de frutos em ambiente natural. A fenologia diferiu entre os habitats e a sincronia das fenofases foi maior na população natural. Apesar de ser nativo de florestas inundáveis, a produção de frutos em terra firme ocorreu ao longo do ano, sugerindo que há poucas restrições para o desenvolvimento de frutos em cultivo.(AU)

Diversity of parasitoid wasps in conventional and organic guarana (Paullinia cupana var. sorbilis) cultivation areas in the Brazilian Amazon

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. (AU)

Association of Pollinators of Different Species of Oil Palm with the Metabolic Profiling of Volatile Organic Compounds.

The development of studies on emissions of volatile organic compounds (VOCs) by inflorescence of oil palms deserves a special attention regarding the importance to reproduction success and for increase of production. This study aimed to evaluate metabolic profiling of VOCs expelled by male and female inflorescences of different oil palm species (African oil palm, Amazonian Caiaué and the interspecific hybrid BRS-Manicoré), associating the composition variability with main pollinators to improve the comprehension of the plant-insect relationship. The phenylpropanoids, terpenoids and the aliphatic hydrocarbons were predominant classes detected in inflorescences of oil palms and the major compound was estragole. This result may be correlated with attraction of Elaidobius pollinators, since these insects were not attracted by Caiaué, which emitted estragole only in trace amounts. However, Caiaué and the hybrid species were visited by other native species whose frequencies were low and their success as pollinators could not be expected.

Nocturnal Bee Pollinators Are Attracted to Guarana Flowers by Their Scents.

Floral scent is an important component of the trait repertoire of flowering plants, which is used to attract and manipulate pollinators. Despite advances during the last decades about the chemicals released by flowers, there is still a large gap in our understanding of chemical communication between flowering plants and their pollinators. We analyzed floral scents of guarana (Paullinia cupana, Sapindaceae), an economically important plant of the Amazon, using chemical analytical approaches, and determined the attractiveness of the scent to its nocturnal bee pollinators using behavioral assays in the field. Pollen loads of attracted bees were also analyzed. Inflorescences of guarana emit strong scents, both during day and at night, with some semi-quantitative differences between day- and night-time scents. Synthetic scent mixtures containing some of the identified floral scent components, including the most abundant ones, i.e., linalool and (E)-ß-ocimene, successfully attracted the nocturnal Megalopta bee pollinators. Pollen analyses revealed that many of the attracted bees had pollen grains from previous visits to guarana flowers on their bodies. Overall, our data show that guarana flowers attract nocturnal bee visitors by their strong scents and suggest that the chemical communication between this plant and its pollinators is a key component in crop production of this economically important plant species.

First record of the indian meal moth, Plodia interpunctella (Hubner 1813) (Lepidoptera: Pyralidae) for Brazil nut / Primeiro registro da traça-das-farinhas Plodia interpunctella (HUBNER 1813) (Lepidoptera: Pyrallidae) em castanha-do-Brasil

This is the first record in Brazil of an infestation of the Indian meal moth, Plodia interpunctella (Hubner 1813), for Brazil nut. P. interpunctella, is a cosmopolitan microlepidoptera of the family Pyralidae, considered an important insect pest of many different stored products. The record was for Brazil nut stored in bags in Itacoatiara county, Amazonas state.

Este é o primeiro registro no Brasil da infestação da traça-das-farinhas, Plodia interpunctella (Hubner 1813), em castanha-do-brasil. Plodia interpunctella é um microlepidóptero pertencente à família Pyralidae, cosmopolita e considerado importante inseto-praga dos mais variados produtos armazenados. O registro foi realizado em castanhas armazenadas em sacarias no município de Itacoatiara, estado do Amazonas.

[The use of different methods to sample the bee fauna (Hymenoptera: Apoidea), a study in the mixed temperate rainforest in Santa Catarina State]. / O uso de diferentes métodos para amostragem da fauna de abelhas (Hymenoptera: Apoidea), um estudo em floresta ombrófila mista em Santa Catarina.

A survey of the bee fauna of Araucaria Forest was performed in the border of a fragment in the district of Porto União, in Santa Catarina State. Samples were carried on monthly between October/2005 and October/2006 with hand nets directly on the flowers, besides three types of traps: chemical baits, trap nests and pantraps. A total of 1711 bees were captured belonging to 164 species, distributed in five families of bees that occur in Brazil. From the total 1339 bees of 130 species were sampled with the hand net, 346 individuals of 72 species were collected in pantraps, 24 bees of nine species were caught in the trap nests and two specimens of one species were sampled with baits. At most 48 species were common to two or more sample methods. Dialictus, with 27 species, was the most representative genus in the area. The exotic Apis mellifera L. was the most abundant species, representing 49.6% of the sampled bees, following by Dialictus sp.11 with 3.2%. The results show evidences of a seasonal pattern of activity of the bees and the importance of the use of complementary methods to survey the fauna. The composition of the bee fauna was similar to many inventories performed in the Araucaria Forest, being Halictidae the most diverse family followed by Apidae.

O uso de diferentes métodos para amostragem da fauna de abelhas (Hymenoptera: Apoidea), um estudo em floresta ombrófila mista em Santa Catarina / The use of different methods to sample the bee fauna (Hymenoptera: Apoidea), a study in the mixed temperate rainforest in Santa Catarina State

A fauna de abelhas da Mata com Araucária foi inventariada no entorno de um fragmento no município de Porto União, SC. Foram realizadas coletas mensais entre outubro/2005 e outubro/2006, com rede entomológica diretamente nas flores, além de três tipos de armadilha: iscas de cheiro, ninhos-armadilha e pratos-armadilha. Foram amostradas 1.711 abelhas pertencentes a 164 espécies, distribuídas nas cinco famílias de abelhas ocorrentes no Brasil. Do total, 1339 abelhas de 130 espécies foram amostradas com rede entomológica, 346 indivíduos de 72 espécies foram coletados nos pratos-armadilha, 24 abelhas de nove espécies foram capturadas através dos ninhos-armadilha e dois indivíduos de uma espécie foram amostrados com iscas de cheiro. No máximo 48 espécies de abelhas foram comuns a duas ou mais metodologias. Dialictus, com 27 espécies, foi o gênero mais representativo na área. A exótica Apis mellifera L. foi a espécie mais abundante, correspondendo a 49,6 por cento dos indivíduos amostrados, seguida por Dialictus sp.11 com 3,2 por cento. Os resultados mostram evidências de um padrão sazonal de atividade das abelhas e a importância da utilização de metodologias complementares na realização de levantamentos de apifauna. A composição da fauna de abelhas foi similar a vários trabalhos realizados em Mata com Araucária, sendo Halictidae a família mais diversa seguida por Apidae.

A survey of the bee fauna of Araucaria Forest was performed in the border of a fragment in the district of Porto União, in Santa Catarina State. Samples were carried on monthly between October/2005 and October/2006 with hand nets directly on the flowers, besides three types of traps: chemical baits, trap nests and pantraps. A total of 1711 bees were captured belonging to 164 species, distributed in five families of bees that occur in Brazil. From the total 1339 bees of 130 species were sampled with the hand net, 346 individuals of 72 species were collected in pantraps, 24 bees of nine species were caught in the trap nests and two specimens of one species were sampled with baits. At most 48 species were common to two or more sample methods. Dialictus, with 27 species, was the most representative genus in the area. The exotic Apis mellifera L. was the most abundant species, representing 49.6 percent of the sampled bees, following by Dialictus sp.11 with 3.2 percent. The results show evidences of a seasonal pattern of activity of the bees and the importance of the use of complementary methods to survey the fauna. The composition of the bee fauna was similar to many inventories performed in the Araucaria Forest, being Halictidae the most diverse family followed by Apidae.