Context affects nestmate recognition errors in honey bees and stingless bees.

Nestmate recognition studies, where a discriminator first recognises and then behaviourally discriminates (accepts/rejects) another individual, have used a variety of methodologies and contexts. This is potentially problematic because recognition errors in discrimination behaviour are predicted to be context-dependent. Here we compare the recognition decisions (accept/reject) of discriminators in two eusocial bees, Apis mellifera and Tetragonisca angustula, under different contexts. These contexts include natural guards at the hive entrance (control); natural guards held in plastic test arenas away from the hive entrance that vary either in the presence or absence of colony odour or the presence or absence of an additional nestmate discriminator; and, for the honey bee, the inside of the nest. For both honey bee and stingless bee guards, total recognition errors of behavioural discrimination made by guards (% nestmates rejected + % non-nestmates accepted) are much lower at the colony entrance (honey bee: 30.9%; stingless bee: 33.3%) than in the test arenas (honey bee: 60-86%; stingless bee: 61-81%; P<0.001 for both). Within the test arenas, the presence of colony odour specifically reduced the total recognition errors in honey bees, although this reduction still fell short of bringing error levels down to what was found at the colony entrance. Lastly, in honey bees, the data show that the in-nest collective behavioural discrimination by ca. 30 workers that contact an intruder is insufficient to achieve error-free recognition and is not as effective as the discrimination by guards at the entrance. Overall, these data demonstrate that context is a significant factor in a discriminators' ability to make appropriate recognition decisions, and should be considered when designing recognition study methodologies.

Frugivory by a stingless bee (Hymenoptera: Apidae)

Frugivory is not frequent among bees. Although stingless bees visit aged fruits for pulp, the use of fresh fruits is recorded only for Trigona hypogea Silvestri, a species that does not visit flowers. Here we report the occurrence of frugivory in Trigona amazonensis (Ducke), a flower-visiting stingless bee.

Utilization of floral resources by bees of the Genus Frieseomelitta von Ihering (Hymenoptera: Apidae)

The present study intended to verify which factors (phylogenetic relationship or local ecological conditions) would determine how Frieseomelitta bees use floral resources. The data obtained in the literature on biocenotic studies of Apoidea visiting flowers in Brazil were analyzed, with identification and quantification of floral resources used by Frieseomelitta species in different areas. The phenogram of similarity on use of resources among Frieseomelitta species was compared to the phylogenetic hypothesis proposed for the group. Among the eight Frieseomelitta species registered in 19 studies, F. doederleini (Friese), F. francoi (Moure), F. languida Moure, F. varia (Lepeletier) e Frieseomelitta sp. nov., were collected using resources from 36 plant families. F. doederleini, F. languida e F. varia centralized their activity in Caesalpiniaceae, Malpighiaceae e Anacardiaceae. The similarities and disparities found among areas and Frieseomelitta species reflected the similarities and differences of the vegetation composition in each area. Frieseomelitta bees presented a forage pattern similar to that one presented by other highly social bees, visiting flowers of many plant species, but concentrating their activities in few plant species. Despite the low phylogenetic relationship between F. languida and F. doederleini, they showed a high similarity on the use of floral resource, while F. varia e F. languida, species with high phylogenetic relationship, showed low similarity in the use of resource. Although the data obtained are not conclusive, it indicates that phylogenetic restrictions do not influence the pattern of use of floral resource by Frieseomelitta bees.

No presente estudo procurou-se investigar fatores que influenciariam o modo de utilização de recursos florais por abelhas Frieseomelitta von Ihering. Os dados obtidos na literatura sobre estudos biocenóticos de Apoidea visitando flores no Brasil foram analisados, com identificação e quantificação dos recursos florais utilizados pelas espécies de Frieseomelitta, em diferentes áreas. O fenograma de similaridade no uso de recursos entre as espécies de Frieseomelitta foi comparado com a hipótese filogenética proposta para o grupo. Das oito espécies de Frieseomelitta registradas em 19 estudos, F. doederleini (Friese); F. francoi (Moure); F. languida Moure, F. varia (Lepeletier) e Frieseomelitta sp. nov.; foram amostradas em 36 famílias botânicas. As similaridades e as disparidades encontradas entre as áreas e entre as espécies de Frieseomelitta refletiram as semelhanças e diferenças da composição da vegetação de cada área. Abelhas Frieseomelitta apresentam padrão de forrageio semelhante ao observado para outros grupos de abelhas eussociais, visitando diversas espécies vegetais, mas concentrando a visita em poucas espécies. F. languida e F. doederleini, embora apresentem parentesco mais distante dentre as espécies do gênero, mostraram maior similaridade no uso dos recursos, enquanto que F. varia e F. languida, espécies mais aparentadas do gênero, não apresentaram similaridades no uso de recursos. Embora as informações disponíveis não sejam, ainda, conclusivas, mostram que as restrições filogenéticas não influenciam específicamente o padrão de utilização dos recursos florais pelas espécies de Frieseomelitta.

Flora visitada pelas abelhas eussociais (Hymenoptera, Apidae) na Serra da Capivara, em caatinga do Sul do Piauí / Flora visited by the eusocial bees (Hymenoptera, Apidae) in a Savanna of the South of Piauí, Brazil

Estudou-se a flora explorada por Apis mellifera L. (abelhas africanizadas) e meliponíneos, em vegetação de caatinga, no Parque Nacional da Serra da Capivara, PI. Durante um ano foram feitas amostragens mensais em dois locais, utilizando-se redes entomológicas para a coleta das abelhas eussociais em visita às plantas. Coletaram-se 69 espécies de angiopermas de 28 famílias nos dois locais amostrados. Leguminosae foi a família com maior número de espécies florais e de maior visitação pelas abelhas eussociais, como ocorreu com outras localidades de caatinga, mas há poucas espécies melitófilas em comum. As plantas coletadas foram visitadas por 12 espécies de meliponíneos e, ou pelas abelhas africanizadas. A. mellifera visitou 32 espécies florais e os meliponíneos 58 espécies, destes destacou-se Trigona spinipes Fabr. com maior espectro de plantas visitadas. O comportamento oportunista foi aparente em A. mellifera, mas não foi observado em todas as espécies de meliponíneos coletadas. A fenologia da flora e da fauna de abelhas foi similar à relatada em outros estudos regionais de mesma formação florística: abundância e heterogeneidade floral durante a estação chuvosa, favorecendo o forrageamento das abelhas, e escassez de recursos florais durante a seca, quando a ocorrência das abelhas se reduz.

This study presents the flora explored by Apis mellifera L. (Africanized honey bee) and stingless bees, and their seasonal phenology, in a caatinga vegetation, located in the Parque Nacional Serra da Capivara, Piauí State, tropical Brazil. During one year, bees were monthly collected with entomological nets, while visiting flowers. Sampling took place in two places. Eusocial bees, A. mellifera and 12 stingless bees species, were collected visiting 69 angiopermas species. Like reported in other studies on caatinga, a plant family heavily foraged was Leguminosae, but there were a few melittophilic species in common. A. mellifera visited 32 floral species and the stingless bees visited 58 species; among them Trigona spinipes Fabr. had the largest spectrum of plant species visited. A. mellifera showed the opportunistic behavior, but this was not observed with the majority of the stingless bee species. Regarding the seasonal phenology, the picture is like others studies conducted in the caatinga: abundance and floral heterogeneity during the rainy station, when the sampling was most effective, and shortage of floral resources during the dry season, when the occurrence of the eusocial bee species was reduced.