Anne Zillikens

Developmental patterns of vitellogenin haemolymph titre and rate of synthesis in adult drone honey bees (Apis mellifera)

Abstract In adult drones temporal changes in the protein content of the haemolymph were determined showing a maximal concentration during the first week after emergence. In this period vitellogenin was found to represent about 5% of the soluble haemolymph proteins. Tracer experiments revealed that the maximal vitellogenin production makes up about 10% of the total synthesis of serum proteins until day 8 and decreases rapidly thereafter. In drones older than 2 weeks, only traces of vitellogenin could be detected in the haemolymph and vitellogenin synthesis ceased. This developmental pattern is compared with worker bees and discussed under the aspects of drone maturation and expression of a female-specific gene in a male genomic environment as realized in the haplo-diploid hymenoptera.

Bimodal pollination system of the bromeliad Aechmea nudicaulis involving hummingbirds and bees.

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.

Bees and Other Insects Recorded on Flowering Trees in a Subtropical Araucaria Forest in Southern Brazil

AbstractFlower visiting insects were monitored on angiosperm trees in an Araucaria forest in Rio Grande do Sul, Brazil. The most abundant flower visitors were workers of the introduced honey bee, Apis mellifera, followed by stingless bees which were represented by 8 species. Together with other bees, they provide the main guild of foragers on flowering trees. The stingless bee fauna of the study area is similar to that of other regions of the Mata Atlântica, especially of former Araucaria forests, but also of montane coastal rain forests.

Ancient associations of aquatic beetles and tank bromeliads in the Neotropical forest canopy

Water reservoirs formed by the leaf axils of bromeliads are a highly derived system for nutrient and water capture that also house a diverse fauna of invertebrate specialists. Here we investigate the origin and specificity of bromeliad-associated insects using Copelatinae diving beetles (Dytiscidae). This group is widely distributed in small water bodies throughout tropical forests, but a subset of species encountered in bromeliad tanks is strictly specialized to this habitat. An extensive molecular phylogenetic analysis of Neotropical Copelatinae places these bromeliadicolous species in at least three clades nested within other Copelatus. One lineage is morphologically distinct, and its origin was estimated to reach back to 12–23 million years ago, comparable to the age of the tank habitat itself. Species of this clade in the Atlantic rainforest of southern Brazil and mountain ranges of northern Venezuela and Trinidad show marked phylogeographical structure with up to 8% mtDNA divergence, possibly indicating allopatric speciation. The other two invasions of bromeliad water tanks are more recent, and haplotype distributions within species are best explained by recent expansion into newly formed habitat. Hence, bromeliad tanks create a second stratum of aquatic freshwater habitat independent of that on the ground but affected by parallel processes of species and population diversification at various temporal scales, possibly reflecting the paleoclimatic history of neotropical forests.

Nest Architecture, Life Cycle and Cleptoparasite of the Neotropical Leaf-cutting Bee Megachile (Chrysosarus) pseudanthidioides Moure (Hymenoptera: Megachilidae)*

Abstract Reproduction in the leaf-cutting bee Megachile (Chrysosarus) pseudanthidioides Moure was studied by trap nesting in secondary Atlantic rain forests on Santa Catarina Island, southern Brazil. Nests were built in borings of hardwood blocks, in small wooden boxes and bamboo canes. The brood cells consisted of an outer layer of overlapping small leaves or pieces of leaves cut oval. They covered a chamber formed of clay. Pieces of flower petals served as the innermost lining of the cells. Nests were constructed October through February. Emergence pattern indicates a bivoltine life cycle with a spring generation emerging December and early January and a second (summer) generation diapausing as prepupae from fall through winter. Metamorphosis then takes place in late winter and imagines emerge only in the following spring, September and October. A cleptoparasitic megachilid, Coelioxys (Acrocoelioxys) tepaneca (Cresson), was found to attack nests of Megachile (C.) pseudanthidioides. This host-parasite relationship was previously unknown.

Nests of Augochlora (A.) esox in Bromeliads, a Previously Unknown Site for Sweat Bees (Hymenoptera: Halictidae)

Five nests of Augochlora (Augochlora) esox (Vachal, 1911) were detected in the rosettes of bromeliads (Aechmaea nudicaulis and A. lindenii) on the island of Santa Catarina, Brazil. Two of the nests were constructed after manipulation of bromeliads as trap nests. Cells were built in the central funnel filled with moist black humus in a scattered way without a detectable pattern. One founding female and all brood stages from eggs to pupae as well as male and female imagines were found in the nests which contained between 3–16 cells each. The uppermost cells contained the youngest larvae whereas pupae and young imagines were found at the bottoms of the nests. Pollen carried by the provisioning female and present in provisions of two nests originated from 18 plant species, in particular Asteraceae and Melastomataceae. Nest architecture is compared to that of congeners, and the use of bromeliads as nest sites for bees is discussed.

Microsatellite loci for Euglossa annectans (Hymenoptera: Apidae) and their variability in other orchid bees

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.

A new species of Adenomera (Amphibia: Anura: Leptodactylidae) from the Atlantic rain forest in Santa Catarina, southern Brazil

As part of the remarkable biodiversity of anurans in the southern range of the Brazilian Mata Atlântica, Adenomera engelsi sp. nov. is described here as a new taxon occurring on the island of Santa Catarina and adjacent coastal mainland. This litter-inhabiting frog is restricted to the Atlantic rain forest biome, living in primary and secondary woods and semi-open areas from sea level to about 900 m a.s.l., partly in sympatry with its congener A. araucaria. Both species are also referred to the Leptodactylus marmoratus group. Adenomera engelsi sp. nov. is a medium-sized member of the genus (snout–vent length 20.9–22.7 mm in males), characterized by a brown dorsal coloration with a maculated pattern of variable dark spots and blotches and a unique advertisement call, consisting of single, unpulsed notes with duration of 95–160 ms, dominant frequency between 3500 and 4300 Hz, and note repetition rates of 10–24 notes/min. Está descrita, como parte da enorme biodiversidade de anuros na região sul da Mata Atlântica brasileira, Adenomera engelsi sp. nov. que ocorre na Ilha de Santa Catarina e no litoral adjacente. A espécie está restrita ao bioma da Mata Atlântica, onde vive no folhiço em mata primária, secundária e áreas semi-abertas, desde o nível do mar até 900 m, parcialmente em simpatria com A. araucaria. Ambas as espécies também são atribuidas ao grupo Leptodactylus marmoratus. Adenomera engelsi sp. nov., de tamanho medio dentro do gênero (SVL 20.9–22.7 mm em machos), é caraterizada pela coloração dorsal marrom, com manchas escuras de tamanho e forma variável e um canto de anúncio distinto, que consiste de notas únicas e sem pulsos de 95–160 ms com frequência dominante entre 3500–4300 Hz e taxa de repetição de 10–24 notas por minuto.

Nests of the soil dwelling sweat bee Augochloropsis caerulans (Hymenoptera: Halictinae) in a waterlogged environment in southern Brazil

ABSTRACT A swampy nest site of the sweat bee Augochloropsis caerulans (Vachal, 1903) in southern Brazil is reported. The bees colonized small earth mounds scattered throughout a water-covered area. Although the substrate of these mounds has high organic matter content, the risk of microbial infestation seems not to be enhanced owing to permanent water saturation. The nests are shallow and can be found 3 cm above the water table. Each nest consists of a cluster of vertically oriented cells on pillars in an oval shaped cavity. The specific nest architecture is thought to mitigate microbial infestation of the brood and to prevent water excess. Nests of A. caerulans are not restricted to water-saturated substrates, but the specific nest architecture presumably enables the bee to propagate in such habitats.

Species richness and seasonality of bees (Hymenoptera, Apoidea) in a restinga area in Santa Catarina, southern Brazil

Species richness and seasonality of a bee community were studied in a restinga area in Palhoça, Santa Catarina, southern Brazil. Twice a month during a year, from September 2004 to September 2005, bees were collected on flowers, in flight and with trap-nests. A total of 784 individuals belonging to 64 species of the families Apidae, Colletidae, Halictidae and Megachilidae were collected. Halictidae was the most rich and abundant family, followed by Apidae. Species richness peaks in summer whereas only a few species of Apidae and mainly Halictidae were active in the coldest months of the year. This clear seasonal pattern of activity appears to be a general characteristic of subtropical bee communities in Brazil. Comparison with others studies in restinga of Santa Catarina was made, as also the total apifauna of restinga in Rio Grande do Sul, Santa Catarina and Paraná are presented.