Initiation of oocyte development in Varroa jacobsoni depends on whether the female enters the brood cell of Apis mellifra before operculation and subsequently sucks hemolymph from a late fifth instar bee larva. Females inserted into the brood 24 h after cell capping, during the spinning phase of the bee larva, do not initiate oocyte development. All stages of mite vitellogenesis and embryogenesis which are described here develop in a close temporal relation to the host stages. A timetable of the first gonocycle is given showing its duration in worker and drone host cells. About 70 h after capping of the bee brood cell, the first egg is laid containing a nearly completed protonymph that hatches within the next day.*The term gonocycle is used here for the development of the oocyte and the embryo until oviposition of the ovoviviparous egg. In case of this mite, only one offspring per gonotrophic cycle is produced. Several overlapping gonocycles occur within one reproductive phase identical with the postcapping period in preimaginal development of the honey bee host. Downloaded by [University of Toronto Libraries]

In order to compare the effectiveness of birds and insects as pollinators, we studied the floral biology of the bromeliad Aechmea nudicaulis (L.) Grisebach in the biome of the Atlantic rain forest, southern Brazil. On Santa Catarina Island, flowering extends from mid-September to the end of December, with diurnal anthesis. The reproductive system is obligatory xenogamy, thus pollinator-dependent. Flowers secrete 31.84 μl of nectar per day, with a mean sugar concentration of 23.2%. Highest nectar volume and sugar concentration occur at the beginning of anthesis. Most floral traits are characteristic for ornithophily, and nectar production appears to be adapted to the energy demand of hummingbirds. Continued secretion of the sucrose-dominated nectar attracts and binds visitors to inflorescences, strengthening trapline foraging behaviour. Experiments assessing seed set after single flower visits were performed with the most frequent visitors, revealing the hummingbird Thalurania glaucopis as the most effective pollen vector. In addition, bees are also functional pollinators, as substantiated by their high visitation frequency. We conclude that this pollination system is bimodal. Thus, there is redundancy in the pollination service provided by birds and bees, granting a high probability of successful reproduction in Ae. nudicaulis.

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AbStrACt. In order to analyze the pollen resources used by the orchid bee Euglossa annectans, samples of larval provisions from cells under construction were taken from 12 different trap nests (wooden boxes) on Santa Catarina Island, southern Brazil. The 43 samples collected between 2002 and 2005 represented all months except December. Overall, 74 pollen types from 24 families were distinguished. Among the 26 pollen types that reached more than 10% in monthly means, the families Melastomataceae, Bromeliaceae, Ochnaceae, Fabaceae, and Myrtaceae were most frequently represented. The Shannon-Weaver diversity index H' for the 43 brood cells varied from 0.10-1.65 and the annual diversity was 0.98. Similarity indices ranged from 0 to 0.87 and were highest during spring and summer. The results characterize E. annectans as a polylectic species. Based on these data, we can conclude that Euglossa females may act as pollinators of many forest species.

Orchid or euglossine bees are conspicuous Hymenoptera of the Neotropics, where they pollinate numerous plants, including orchids. Allozyme-based analyses have suggested that their populations suffer from inbreeding, as evidenced by so-called diploid male production. We have developed nine polymorphic microsatellite loci for the widespread Euglossa annectans, with observed heterozygosities ranging from 0.143 to 0.952 and between 2 and 9 alleles per species. These loci will be useful for analysis of relatedness, population genetic structure and diploid male production in this and related species.

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The present study contributes to the knowledge of the apifauna and its food sources on the Santa Catarina Island, SC, southern Brazil. Bees and their food sources were recorded through non-systematic collections, between November 1999 and April 2008, in several environments on the island. A total of 169 species of bees were captured on 126 species of melittophilous plants. The majority of plants recorded are subshrub and shrub species, with only nine species of trees. 91% of the bee species were collected on native plants, which represent 64% of the plant species, while only seven species of bees (4%) were captured exclusively on exotic plants (27% of the plant species). In our study, we show the importance of non-arboreal native plants in maintaining a rich diversity of bees and we indicate plant species that can be used as target species in rapid surveys of the subtropical apifauna in Brazil. The spectrum of species with oligolectic habits and their pollen sources as well as the recording of new food sources for rare species in surveys of bees on flowers are discussed.