No abstract

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.

1992). Host specicity and seed dispersal of Psittacanthus robustus (Loranthaceae) in south-east Brazil.ABSTRACT. Psillacanlhus robuslus (Loranthaceae) is a Neotropical mistletoe which grows mainly on species of Vochysiaceae in Brazilian 'cerrado' regions. Its parasitizing pattern involves: (a) the height and the aspect of the crown of the host-plants; (b) the presence of sticky substance in the fruits of the parasite; and (c) the feeding behaviour and habitat selection of the dispersal agent, the swallowtanager Tersina viridis viridis. The feeding behaviour of this bird on fruits of P. robustus facilitates seed release and seedling establishment; its foraging habit and habitat selection account for high concentrations of the parasites on their preferred host-plants. RESUMO. Psittacanthus robustus (Loranthaceae) e uma erva-de-passarinho neotropical que parasita principalmente especics de Vochysiaceae em cerrados brasileiros. O padrao de parasitismo tem relacao com: (a) a altura e o aspecto da copa das plantas hospedeiras; (b) a presence de substancia viscosa no fruto da parasita; e (t) o comportamento alimentar e a selec,ao de habitat do agente dispersor, o sai-andorinha Tersina viridis viridis. Seu comportamento alimentar facilita a liberac.ao da semente e o estabelccimcnto da plantula; seu habito de forrageamento e selec.ao de habitat ocasionam alta concentrac.ao de parasitas nas suas plantas hospedeiras principais.

The ecotone zone between epigean and hypogean environments has been delimited for two limestone caves using a new method proposed herein. The richness and the diversity of the ecotone, epigean and hypogean environments and their similarities have also been determined. The ecotones were delimited using a similarity matrix between the inner and outer sectors of each cave. The ecotone of Dona Rita's cave was estimated to be 12 m long and the ecotone of Retiro's cave 16 m. The richness (S) of arthropods in Dona Rita's cave was higher in the ecotone (S = 131), intermediate in the epigean environment (S = 75) and lower in the hypogean system (S = 45). The invertebrate diversity (H′) was lower in the hypogean environment (H′ = 2.89) and not statistically different between the epigean environment and the ecotone (H′ = 3.56 and H′ = 3.76, respectively). The richness in Retiro's cave was higher in the ecotone (S = 86), intermediate in the epigean environment (S = 39) and lower in the hypogean system (S = 12). The invertebrate diversity was lower in the hypogean environment (H′ = 0.48), intermediate in the ecotone (H′ = 3.02) and higher in the epigean region (H′ = 3.29). Species migration patterns, differential environmental barriers and determination of accidental versus trogloxenes/troglophylous species are topics that are primarily approached by establishing ecotone zones in caves. The aim of the present paper is to establish the delimitation of theses zones.

In Brazil, only limestone caves and a few caves in sandstone, iron ore and granite rocks had their invertebrate communities evaluated. Being such, the present study aimed to promote a comparative analysis of the structure of the invertebrate communities in caves associated to carbonatic, magmatic, siliciclastic and ferruginous rocks of the Brazilian Atlantic forest. Significant differences in the relative richness, abundance and diversity were observed between lithologies. The average relative richness was higher in the ferruginous caves (0.53 spp). The total number of troglomorphic species was significantly different among caves and the highest average richness occurred at ferruginous caves (5.79 spp/cave). Siliciclastic, carbonatic and magmatic caves presented a higher quantitative similarity of the fauna. Ferruginous caves revealed communities with a fauna composition different from the other lithologies. The total richness of invertebrates correlated significantly and positively with the linear development in the siliciclastic caves (R s = 0.67, P \ 0.05), carbonatic (R s = 0.71, P \ 0.05) and ferruginous (R s = 0.74, P \ 0.05). The rock type in which the cave is inserted can determine differences in the richness of invertebrate troglophyles and troglobites. Therefore, on creating value attributes, the size of the caves should always come related to their lithology by the fact that same sized caves associated to different lithologies, possess communities with quite diverse structures.

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.

The trophic structure and natural history of bat guano invertebrate communities in Brazilian caves was compared with information concerning bat guano communities in other caves throughout the world. The basis of Brazilian cave guano food webs are detritivorous organisms that directly consume guano, and microorganisms that live off deposits. These include mites, the most common organisms on guano, and others such as springtails (Acherontides eleonorae Palacios-Vargas & Gnaspini-Netto 1992), booklice (e.g. Psyllipsocidae), beetles (e.g. Dermestidae, Cholevidae), moths (e.g. Tineidae) and flies (e.g. Phoridae, Milichiidae). Facultative detritivores are also common, forming large populations when other organic substrata, such as vegetable debris, become scarce, as in the case of permanently dry caves. These are isopods (e.g. Trichorrhina sp.), diplopods (e.g. Pseudonannolene sp.), cockroaches, crickets (e.g. Endecous sp.), and silverfish (e.g. Coletinia brasiliensis Mendes & Ferreira in press). Other detritivores, like flatworms, earthworms, gastropods and harvestmen, are rarely found. Detrivores are in turn consumed by a wide range of predators, like pseudoscorpions (e.g. Chernetidae), spiders (e.g. Loxosceles similis Moenkhaus 1898, Oecobius annulipes Lucas 1846), and heteropterans (Reduviidae Zelurus variegatus Costa-Lima 1940). Facultative predators, like scorpions and whip-scorpions attracted by prey items, are also occasionally abundant. Food webs of bat guano communities in Brazilian caves are richer in species than those elsewhere.

Neotropical Entomology 35(3): 285-298 (2006) Revisão sobre a Influência de Fatores Proximais na Nidificação de Vespas e Abelhas Solitárias (Hymenoptera: Aculeata) em Cavidades Pré-Existentes no Lenho PALAVRAS-CHAVE: Vespa solitária, abelha solitária, guilda, cavidade em árvores, ninho-armadilha ABSTRACT -Guilds of Aculeate solitary wasps and bees that nest in preexisting cavities in wood are important components of terrestrial ecosystems because they engage in several ecological interactions (e.g. predation and pollination) with other species of plants and animals. Spatial and temporal variations in richness and abundance of solitary wasps and bees can be related to changes in environmental structure and in the diversity of other groups of organisms. The nesting period of these Aculeata is their most critical life cycle stage. Females of solitary wasp and bee species invest relatively more time constructing and provisioning their nests than do females of social species. Differently from species that nest in the soil or construct exposed nests, the main factors affecting the reproductive success of solitary species nesting in preexisting wood holes are still unknown. Our objective is to provide an overview of the role of proximate causes of nesting failure or success among solitary wasps and bees (Aculeata), for designing effective conservation and management strategies for these Hymenoptera.