Yasmine Antonini

Yeast communities associated with stingless bees

The yeast communities associated with the stingless bees Tetragonisca angustula, Melipona quadrifasciata and Frieseomelitta varia were studied. The bees T. angustula and F. varia showed a strong association with the yeast Starmerella meliponinorum. M. quadrifasciata more frequently carried a species related to Candida apicola, but also vectored low numbers of S. meliponinorum. Some of the yeasts isolated from adult bees were typical of species known to occur in flowers. Other yeast species found in adult bees were more typical of those found in the phylloplane. S. meliponinorum and the species in the C. apicola complex, also part of the Starmerella clade, may have a mutualistic relationship with the bees studied. Many yeasts in that group are often found in bees or substrates visited by bees, suggesting that a mutually beneficial interaction exists between them.

The flowering-visiting bees at the ecological station of the Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil

The richness and the composition of bee species at the ecological station of the Universidade Federal de Minas Gerais, Campus Pampulha, Belo Horizonte, MG, Brazil, was recorded from January to December 1996. The bee fauna of the ecological station is rich (98 species) in low-density populations species (350 individuals). The composition of the bee fauna is seasonal (Q = 29.35, df = 11, P < 0.002), however the composition in flowering plants showed no seasonality (Q = 17.30, df = 11, P < 0,099). The bee species visited 23 flowering plant species from 11 families. Asteraceae (111 individuals in 53 species) and Convolvulaceae (88 individuals in 26 species) were the most visited families. There was a positive relation between bee abundance and the number of flowering plants (r2 = 0.72, P = 0.0011, n = 12) and bee richness and abundance of flowering plants (r2 = 0.46; P = 0.010, n = 12). In the studied area and other sites at Southeastern Brazil, Apidae was the richer and abundant family and Halictidae was the richer and abundant at South Brazil. Despite its localization in a heavily urbanized area, the ecological station supports a rich bee species assembly.

CANDIDA BATISTAE, A NEW YEAST SPECIES ASSOCIATED WITH SOLITARY DIGGER NESTING BEES IN BRAZIL

AbstractSeveral strains of the new yeast species Candida batistae have been isolated from larval provisions, larvae, and pupae of the solitary bees Diadasina distincta and Ptilotrix plumata (Apidae...

The value of a tree species (Caryocar brasiliense) for a stingless bee Melipona quadrifasciata quadrifasciata

The expansion of crop lands and increased logging for charcoal production in the Brazilian savannahs (“cerrados”) has reduced richness and abundance of Meliponini bees. This may be a consequence of limitation in the availability of potential nesting substrate. The role of a cerrado-tree (Caryocar brasiliense) in providing nesting substrate for Melipona quadrifasciata quadrifasciata was evaluated. Tree (p= 0.006) and branch (p= 0.001) diameters, number of suitable branches (n= 513), height of the trees and availability of trees suitable for bee nesting were all important to the conservation of M. quadrifasciata. However, the high availability of nesting substrate did not seem to limit nest density nor cause the clumped pattern of nest distributions found for the study site. Nests (n= 48) were found mainly in individuals of C. brasiliense (n= 46) suggesting an active tree selection. In addition, nests located on the highest branches (mean = 4.6 m, sd = 1 m, n= 46) had lower probability of being extirpated by human honey collectors.

Diversidade e comportamento dos insetos visitantes florais de Stachytarpheta glabra Cham. (Verbenaceae), em uma área de campo ferruginoso, Ouro Preto, MG

The influence of abiotic factors and floral resources on the frequency of insect visitors to Stachytarpheta glabra Cham was assessed in an area of ferruginous fields, Ouro Preto, MG. A total of 312 insects were collected, belonging to 28 species. The highest abundances were for Oxaea flavescens Klug (25%), Vespidae sp1 (11.5%), Vespidae sp2 (11%), Antheos clorinde Hubner (10.3%) and Vespidae sp3 (10%). There was a positive relation of abundance with light intensity (r2 = 0.66, b = 0.82, P < 0.001) and temperature (r2 = 0.40, b = 0.65, P = 0.001), and a negative relation with relative humidity (r2 = 0.34, b = -0.60, P < 0.001). The number of flowers and inflorescences (rS = 0.81, n = 20, P < 0.001 e rS = 0.82, n = 20, P < 0.001, respectively) influenced the abundance of visits. No significant relation was found with plant height. Halictidae prefer to forage at high temperatures and light intensity. Large bees (Apidae and Andrenidae), on the other hand, are more tolerant to temperature variations and forage during the whole day. Vespidae prefer high temperatures but tolerate variation in light intensity. Lepidoptera forage preferentially during periods of high light intensity and temperature. Butterflies, moths, Eulaema nigrita Lepeleier and Apis mellifera L. are the potential pollinators whereas Vespidae, Halictidae, Bombus atratus Franklin and O. flavescens were thieves in S. glabra flowers.

Flebotomíneos do Parque Nacional Cavernas do Peruaçu, MG

We surveyed the phlebotomine fauna in the Parque Nacional Cavernas Do Peruacu, Minas Gerais, Brazil, aiming to associate the presence of vector with the risk of leishmaniasis transmission. Field captures were performed with CDC light traps between February and March 2003. A total of 436 sand flies were captured, belonging to 14 species. The predominant species (28.7%) was Lutzomyia ischnacantha Martins, Souza e Falcao, followed by L. renei (27,06%) and L. cavernicola (13,07%). The finding of L. intermedia, a species that is incriminated as vector of the cutaneous leishmaniasis, has to be taken into account.

Pollen and nectar harvesting by the stingless bee Melipona quadrifasciata anthidioides (Apidae: Meliponini) in an urban forest fragment in Southeastern Brazil

Pollen and nectar sources used by Melipona quadrifasciata anthidioides were recorded at Parque Estadual da Serra do Rola‐Moça during one year. Eighty‐nine workers of M. quadrifasciata visited flowers of 16 out of 83 flowering plant species recorded at the site. The flowers visited belonged mainly to a few families, mostly Solanaceae and Myrtaceae. Abundance of bees was not correlated to food availability. From most plant species the workers of M. quadrifasciata gathered either pollen or nectar. Fifty‐five percent of visited plant families overlapped among Parque Estadual da Serra do Rola‐Moça and four other sites in Bahia, São Paulo and Paraná States. Resumo Inventariou‐se as espécies de plantas que Melipona quadrifasciata anthidioides utiliza para coleta de pólen e néctar. Oitenta e nove operárias de M. quadrifasciata visitaram 16 (19.3%) das 83 espécies de plantas floridas. Setenta por cento das plantas visitadas foram principalmente espécies de Solanaceae e Myrtaceae. A abundância de abelhas nas flores não se correlacionou com a disponibilidade de recursos. Melipona quadrifasciata coletou somente pólen ou néctar da maioria das plantas que visitou. Houve uma similaridade média de 55% entre o conjunto de espécies de plantas visitadas por M. quadrifasciata no Parque Estadual da Serra do Rola‐Moça e aqueles visitados em locais nos Estados da Bahia, São Paulo e Paraná.

Inverse density-dependent and density-independent parasitism in a solitary ground-nesting bee in Southeast Brazil

Aspects of the population dynamics of a solitary ground-nesting oligolectic bee, Diadasina distincta (Holmberg 1903) (Hymenoptera Anthophoridae), were studied in relation to the number of parasitized nests in aggregations of different sizes. inversely density-dependent parasitism by bombyliid flies and density- independent mortality by fungi together explained most of the variation in population size. There was a significant negative correlation between the number of nests in an aggregation and parasitism by bombyliid flies. Bombyliids accounted for 19.4% of mortality and two fungal species for an additional 19%. It is hypothesized that male patrolling in larger aggregations accounted for lower parasitism rates by bombyliid flies.

Compositional changes in bee and wasp communities along Neotropical mountain altitudinal gradient

Climate conditions tend to differ along an altitudinal gradient, resulting in some species groups’ patterns of lower species richness with increasing altitude. While this pattern is well understood for tropical mountains, studies investigating possible determinants of variation in beta-diversity at its different altitudes are scarce. We sampled bee and wasp communities (Hymenoptera: Aculeata) along an altitudinal gradient (1,000–2,000 m.a.s.l.) in a tropical mountainous region of Brazil. Trap nests and Moericke traps were established at six sampling points, with 200 m difference in altitude between each point. We obtained average climate data (1970–2000) from Worldclim v2 for altitudes at each sampling site. Nest traps captured 17 bee and wasp species from six families, and Moericke traps captured 124 morphospecies from 13 families. We found a negative correlation between altitude and species richness and abundance. Temperature, precipitation, water vapor pressure, and wind speed influenced species richness and abundance, and were correlated with altitude. β-diversity was primarily determined by species turnover as opposed to nestedness, and Aculeate community similarity was higher for more similar altitudinal ranges. Moericke traps seem to be more efficient for altitudinal surveys compared to nest traps. We found high occurrence of singleton and doubleton species at all altitudes, highlighting the need for long-term studies to efficiently assess hymenopteran diversity in these environments.

Does scale matter? The influence of three-level spatial scales on forest bird occurrence in a tropical landscape

Consequences of habitat fragmentation for species occurrence are amongst the most important issues in landscape and conservation ecology. Empirical and theoretical studies have demonstrated that the total amount of habitat, patch size and connectivity have nonlinear effects on species survival on multiple spatial and temporal scales. Therefore, population models need to incorporate multiple scales, which can be extremely valuable to prioritizing conservation efforts in these changing landscapes. We tested how the amount and configuration of habitat affect understory bird species occurrence using fine to broad-scale habitat features. We used playback to sample birds in 13 Atlantic Forest fragments in Southeast Brazil. Microhabitat, local and regional landscape variables were tested against bird occurrence. Our results demonstrate that different bird species respond to different habitat scales. Sclerurus scansor, Xiphorhynchus fuscus, Automolus leucophthalmus, Drymophila ochropyga, Mackenziaena leachii, and Chiroxiphia caudata were most influenced by tree height and diameter (microhabitat characteristics), S. scansor, F. serrana and Pyriglena leucoptera were most influenced by forest cover and red-edge reflectance(local-scale metrics) and S. scansor, X. fuscus, D. ochropyga, P. leucoptera, F. serrana and M. leachii had area, core area and functional connectivity index (landscape features) as stronger predictors of species occurrence. Small forest fragments acted as corridors and increased overall connectivity of the entire community. The most effective means of maintaining long-term population connectivity of understory birds involves retaining both large and small areas, including forests with different micro-habitat characteristics. No management approach based on a single-scale would benefit all species. Implementing multiscale conservation strategies are necessary for maintaining long-term viability of forest birds on tropical landscapes.