Bees are the most important diurnal pollinators of angiosperms. In several groups of bees a nocturnal/crepuscular habit developed, yet little is known about their role in pollination and whether some plants are adapted specifically to these bees. We used a multidisciplinary approach to investigate the reproductive biology and to understand the role of nocturnal/crepuscular bees in pollination of Campomanesia phaea (Myrtaceae), popularly named cambuci. We studied the floral biology and breeding system of C. phaea. We collected the floral visitors and tested the pollinators' effectiveness. We also determined the floral scents released at night and during daytime, and studied behavioural responses of crepuscular/nocturnal bees towards these scents. The flowers of cambuci were self-incompatible and had pollen as the only resource for flower visitors. Anthesis lasted around 14 h, beginning at 04:30 h at night. The flowers released 14 volatile compounds, mainly aliphatic and aromatic compounds. We collected 52 species of floral visitors, mainly bees. Nocturnal and crepuscular bees (four species) were among the most frequent species and the only effective pollinators. In field bioassays performed at night, nocturnal/crepuscular bees were attracted by a synthetic scent blend consisting of the six most abundant compounds. This study describes the first scent-mediated pollination system between a plant and its nocturnal bee pollinators. Further, C. phaea has several floral traits that do not allow classification into other nocturnal pollination syndromes (e.g. pollinator attraction already before sunrise, with pollen as the only reward), instead it is a plant specifically adapted to nocturnal bees.

Tetrapedia diversipes Klug is herein reported for the first time to be the host of the cleptoparasite Coelioxoides waltheriae Ducke. Because these two genera had been previously recognized as sister taxa [A. Roig-Alsina. 1990. Coelioxoides Cresson, a parasitic genus of Tetrapediini (Hymenoptera: Apoidea). Journal of the Kansas Entomological Society 63: 279-287], the authors wished to learn to what extent biological information and immature stages reflected this relationship. Tetrapedia diversipes normally nests in holes in wood such as old beetle burrows, and it was induced to use trap nests for this study. Many aspects of the nesting behavior of females of this species are described, including the following: diurnal flight period; sleeping habits; nest structure; nest provisioning; egg placement; and sequence of nest construction, provisioning, and oviposition. Eggs produced by this species are categorized as ''giant'' (K. Iwata and S.F. Sakagami. 1966. Gigantism and dwarfism in bee eggs in relation to the mode of life, with notes on the number of ovarioles. Japanese Journal of Ecology 16: 4-16). Its first instar was discovered to be pharate within the chorion while the following four instars actively feed. Defecation starts early in the last larval stadium. Females use floral oils both in nest construction and in provisioning, and they carry pollen, oil, and soil with their scopae. The biology of T. diversipes was compared with that of other species in the genus and then compared with that of other apines that are known to nest in preformed cavities and that provision nests with pollen and floral oils. The host-nest searching behavior of Coelioxoides waltheriae is described. The cleptoparasite introduces its egg into the closed cell of the host shortly after cell closure. This egg is characterized as ''small'' (Iwata and Sakagami, ibid.) and has a very short incubation period. The highly modified first instar immediately feeds on the host egg and grows remarkably fast on the host yolk. This species has only four instars. Rates of development of the host and cleptoparasite are compared. Both have four ovarioles per ovary. Eggs, first instars, last larval instars, and pupae of host and cleptoparasite are taxonomically described and compared. In conclusion, the immatures of Coelioxoides and Tetrapedia are quite distinct from those of other known apids. While these two genera are probably sister genera based on the similarities identified by Roig-Alsina (op. cit.) and by this study, they are quite different from one another based on features of the eggs, first instars, and pupae. Recent issues of the Novitates may be purchased from the Museum. Lists of back issues of the Novitates and Bulletin published during the last five years are available at World

ReSUMoExistem cerca de 330 espécies de abelhas que usam óleo coletado em flores para alimentar as larvas e revestir as células de cria, e pertencem aos grupos Melittinae (Melittidae), Centridini, tapinostapidini e tetrapediini (Apidae). As últimas três tribos são exclusivamente do hemisfério oeste e especialmente diversas na região Neotropical. Abelhas coletoras de óleo possuem modificações nas pernas ou esterno (Tapinotaspoides) para coletar, manipular e transportar o óleo. essas estruturas normalmente são relacionadas aos diferentes tipos de elaióforos (as glândulas secretoras de óleo): epitelial ou em tricomas. estima-se que mais de 1800 espécies de plantas de nove famílias ofereçam óleo floral como recurso, sendo Malpighiaceae a mais importante. Neste trabalho organizamos uma revisão sobre o processo de nidificação de algumas abelhas coletoras de óleo, bem como sobre associação com as plantas produtoras de óleo. As abelhas coletoras de óleo são de vida solitária, mas algumas espécies nidificam em agregação. As espécies que fazem ninho no solo usam superfícies planas ou barrancos (como Epicharis, Monoeca, Lanthanomelissa). existem espécies que utilizam ninhos de cupins e formigas (como Ptilotopus) ou cavidades pré-existentes (como Tetrapedia). os parasitas geralmente são abelhas cleptoparasitas como Coelioxys, Coelioxoides, Mesoplia, Mesocheira, Protosiris, Paraepeolus, que ovipositam dentro da célula de cria e suas larvas (com mandíbulas afiadas) matam o ovo ou larva da hospedeira. Apesar de todo avanço no conhecimento sobre as abelhas coletoras de óleo ainda restam questões a serem desvendadas sobre a utilização deste produto pelas abelhas Palavras-chave: Flores produtoras de óleo, Centridini, tapinotaspidini, tetrapediini, Apoidea.

No abstract

Anthodioctes megachiloides Holmberg, 1903 é uma abelha solitária que utiliza cavidades pré-existentes para construir o ninho. Ninhos armadilhas de madeira foram instalados no jardim do Laboratório de Abelhas no campus da Universidade de São Paulo. As armadilhas consistiram de orifícios circulares de 4 a 5 mm de diâmetro, com profundidade de 5 a 7 cm. Tubos de papel foram inseridos nos orifícios de tal maneira que pudessem ser posteriormente e periodicamente inspecionados. Dados sobre a biologia, construção de ninho, comportamento da fêmea e atividade dos parasitas foram obtidas através de observações diretas durante a primavera e verão de 2001/2002. Fêmeas de A. megachiloides iniciaram atividade em meados de agosto e fundaram um total de 40 ninhos na primavera de 2001. Resina vegetal é usada para cobrir as células, construir as partições e fechamento do ninho. De 24 ninhos examinados, 18 continham imaturos mortos, indicando que a taxa de mortalidade foi alta. Uma espécie de vespa da família Sapygidae foi detectada como cleptoparasita de A. megachiloides.

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 sub-species 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 remarkably 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.

Abstract:For this work, we considered the results of four studies that sampled bees on flowers in the two main biomes of São Paulo State: Atlantic forest (3 locations) and 'cerrado' (4 locations). We found 276 species of bees belonging to 88 genera: 207 species and 78 genera in the Atlantic forest and 105 genera and 40 species in the 'cerrado' biome. Apidae family was the most represented in both biomes. In the sampled areas, bees visited 433 plant species: 361 in the Atlantic forest and 75 in the 'cerrado'.

The foraging activity of diurnal bees often relies on flower availability, light intensity and temperature. We do not know how nocturnal bees, which fly at night and twilight, cope with these factors, especially as light levels vary considerably from night to day and from night to night due to moon phase and cloud cover. Given that bee apposition compound eyes function at their limits in dim light, we expect a strong dependence of foraging activity on light intensity in nocturnal bees. Besides being limited by minimum light levels to forage, nocturnal bees should also avoid foraging at brighter intensities, which bring increased competition with other bees. We investigated how five factors (light intensity, flower availability, temperature, humidity, and wind) affect flower visitation by Neotropical nocturnal bees in cambuci (Campomanesia phaea, Myrtaceae). We counted visits per minute over 30 nights in 33 cambuci trees. Light intensity was the main variable explaining flower visitation of nocturnal bees, which peaked at intermediate light levels occurring 25 min before sunrise. The minimum light intensity threshold to visit flowers was 0.00024 cd/m2. Our results highlight the dependence of these nocturnal insects on adequate light levels to explore resources.