No worker reproduction in the Australian stingless bee Trigona carbonaria Smith (Hymenoptera, Apidae)

Brood of the Australian stingless bee Trigona carbonaria was investigated using microsatellites to determine the origin of males. Genotypes of over 1800 males sampled from ten unrelated colonies were consistent with the hypothesis that the resident queen was the sole mother of the males and that workers, either natal or non-natal (parasitic), did not contribute to the production of males. Dissections of 300 workers from a total of four colonies showed that ovaries are present but not activated. Received 6 June 2007; revised 20 August 2007; accepted 12 September 2007.     

Development of a Species-Diagnostic Marker for Identification of the Stingless Bee Trigona pagdeni in Thailand

A species-diagnostic SCAR marker for identification of the stingless bee (Trigona pagdeni Schwarz) was successfully developed. Initially, amplified fragment length polymorphism analysis was carried out across representatives of 12 stingless bee species using 64 primer combinations. A 284 bp band restrictively found in T. pagdeni was cloned and sequenced. A primer pair (CUTP1-F/R) was designed and tested for species-specificity in 15 stingless bees. The expected 163 bp fragment was successfully amplified in all examined individuals of T. pagdeni (129/129). Nevertheless, cross-species amplification was also observed in T. fimbriata (1/3), T. collina (11/112), T. laeviceps (1/12), and T. fuscobalteata (15/15), but not in other species. SSCP analysis of CUTP1 further differentiated T. fuscobalteata and T. collina from T. pagdeni. Although T. laeviceps, T. fimbriata, and T. pagdeni shared an identical SSCP genotype, they are not taxonomically problematic species.     

Effect of Australian Propolis from Stingless Bees (Tetragonula carbonaria) on Pre-Contracted Human and Porcine Isolated Arteries

Bee propolis is a mixture of plant resins and bee secretions. While bioactivity of honeybee propolis has been reported previously, information is limited on propolis from Australian stingless bees (Tetragonula carbonaria). The aim of this study was to investigate possible vasomodulatory effects of propolis in KCl-precontracted porcine coronary arteries using an ex vivo tissue bath assay. Polar extracts of propolis produced a dose-dependent relaxant response (EC₅₀=44.7±7.0 μg/ml), which was unaffected by endothelial denudation, suggesting a direct effect on smooth muscle. Propolis markedly attenuated a contractile response to Ca²⁺ in vessels that were depolarised with 60 mM KCl, in Ca²⁺-free Krebs solution. Propolis (160 µg/ml) reduced vascular tone in KCl pre-contracted vessels to near-baseline levels over 90 min, and this effect was partially reversible with 6h washout. Some loss in membrane integrity, but no loss in mitochondrial function was detected after 90 min exposure of human cultured umbilical vein endothelial cells to 160 µg/ml propolis. We conclude that Australian stingless bee (T. carbonaria) propolis relaxes porcine coronary artery in an endothelial-independent manner that involves inhibition of voltage-gated Ca²⁺ channels. This effect is partially and slowly reversible upon washout. Further studies are required to determine the therapeutic potential of Australian stingless bee propolis for conditions in which vascular supply is compromised.     

Pollen Harvest by Stingless Bee Foragers (Hymenoptera,Apidae, Meliponinae)

Data on pollen load capacity and flower constancy are discussed for nine stingless bee species. The foragers present high levels of flower constancy and often visit only one flower type (on average 97% of bee foragers), rarely a few flower types (on average 3% of bee foragers), during the same foraging trip. The latter foragers exhibit no tendencies for choosing similar sources, related either to flower type or to pollen type. Pollen load capacity (the ratio between pollen load weight/worker weight) decreases as forager body weight increases, so it is larger in smaller stingless bees species and smaller in larger ones. Nevertheless, it seems that specific load capacity also depends on pollen types.     

Production of Sexuals and Mating Frequency in the Stingless Bee Tetragonisca angustula (Latreille) (Hymenoptera, Apidae)

Queen, worker, and male production was studied for 1 year in three queenright colonies of Tetragonisca angustula (Latreille). We sampled brood combs monthly and noticed that the number of brood cells and production of individuals were similar among colonies. Although the production of queens did not vary significantly, the frequencies of workers, males, and the number of cells among the combs varied over time. The production of males was highly seasonal, occurring mostly from February to April, coinciding with the period of intense brood cells production, when colonies produced more males and less workers, resulting in a negative correlation. Although the frequency of queens has not varied in time, the seasonal availability of males affected the mating frequency and the time spent since emergence until fertilization of queens. In the T. angustula colonies studied, the population dynamics was highly seasonal and the mating success depended of male production, according to the season.     

A new species of Syntretus Foerster (Hymenoptera: Braconidae: Euphorinae), a parasitoid of the stingless bee Trigona carbonaria Smith (Hymenoptera: Apidae: Meliponinae)

A new species of euphorine braconid, Syntretus trigonaphagus sp. nov., is described and illustrated. This is the first Australian Syntretus species to be described and the first record of braconids parasitising Trigona Jurine stingless bees. Egg-laying by adults and emergence of larvae from the host Trigona carbonaria is detailed. A 12S ribosomal rRNA gene fragment was sequenced to confirm the association of larvae and adults of the wasp parasitoid.     

Temporal Response of Foragers and Guards of Two Stingless Bee Species to Cephalic Compounds of the Robber Bee <Emphasis Type="Italic">Lestrimelitta niitkib</Emphasis> (Ayala) (Hymenoptera,Apidae)

Lestrimelitta spp. are stingless bees that steal food and nesting materials from other highly social bees to survive. Though most of their victim species respond, either aggressively or submissively, to cephalic components of Lestrimelitta, little is known about if such response changes at some point during extended periods of exposure. Moreover, potential synergistic effects due to a mixture of victim’s alarm/defense pheromones and Lestrimelitta mandibular pheromones, like in an actual attack, have not been examined so far. In this paper, we investigated the response of two species of non-robber stingless bees, Scaptotrigona mexicana (Guérin) and Tetragonisca angustula (Latreille), to (a) cephalic compounds from crushed heads of nestmates, (b) cephalic compounds of Lestrimelitta niitkib (Ayala), and (c) a mixture of (a) and (b). We found that even though T. angustula did not react to nestmates’ crushed head, its response towards L. niitkib cephalic compounds was stronger and lasted longer than that of S. mexicana. Interestingly, the addition of crushed heads of the non-robber species to L. niitkib crushed heads caused no significant increase in the alarm response of both species. It may be that the absence of an alarm pheromone in T. angustula made this species more receptive to extraneous odors, which is not the case for S. mexicana; however, more species must be studied to elucidate any pattern regarding the absence/presence of alarm pheromones and the corresponding response to intruders’ pheromones.     

Pollen Types Used by the Native Stingless Bee, <Emphasis Type="Italic">Tetragonisca angustula</Emphasis> (Latreille), in an Amazon-Chiquitano Transitional Forest of Bolivia

Samples of corbicular and stored pollen gathered by Tetragonisca angustula (Latreille, 1811) in an Amazon-Chiquitano transitional forest during the dry season were analyzed. The pollen spectrum was established as well as the dynamics of the relationship between the stingless bee and the surrounding flora. Pollen samples obtained from three rational hives were subjected to acetolysis and 55 pollen types were identified, the most frequent being from Anadenanthera (Fabaceae), Chenopodiaceae, and Dydimopanax (Araliaceae). Significant differences in pollen families used between hives along the months of collection were found in stored pollen and non-significant differences in corbicular pollen. Mean values of alpha diversity (H′) showed T. angustula as a generalist while beta diversity qualitatively showed that pollen composition was similar between two hives both of which differed from the third hive. Pollen types in corbicular and stored pollen were in general related with richness of flowering plants in the foraging area; the pollen offer was less diverse than the pollen collected, and a trend to prefer the collection of pollen from the most abundant flowering species could be discerned. T. angustula showed polylectic feeding habits and a capacity to adapt to food availability.     

Effect of Ambient Temperature on the Body Temperature Rhythm of Male Gray Mouse Lemurs (Microcebus murinus)

In order to cope with the seasonal variations in ambient temperature and food availability in the natural habitat, gray mouse lemurs (Microcebus murinus) exhibit adaptive energy-saving mechanisms similar to those in hibernating species with seasonal and daily heterothermia. To determine thermoregulatory responses, via telemetry we recorded body temperature and locomotor activity variations during the breeding season in three captive male mouse lemurs kept at ambient temperatures (T_a) ranging from 18° to 34°C. Rhythms in body temperature and locomotor activity were clearly exhibited regardless of ambient temperature. As _a increased, mean body temperature increased from 36.5 ± 0.1°C to 37.6 ± 0.3°C, with significant change in the amplitude of the body temperature rhythm when _a rose above 28°C. Effects of _a were mostly due to changes in the fall in body temperature occurring daily at the beginning of the light phase when the subjects entered diurnal sleep. The daily decrease in body temperature was not modified by exposure to ambient temperatures from 18°C to 28°C whereas it disappeared under warmer condition. Changes in locomotor activity levels only delayed the occurrence of thermoregulatory modulation. These results strongly suggest that, during the breeding season, the thermoneutral zone of mouse lemurs is close to 28°C and that the diurnal fall in body temperature could be considered as an important adaptive energy-saving mechanism adjusted to ecological constraints.     

Feeding Preference of Native Subterranean Termites (Isoptera: Rhinotermitidae: Reticulitermes) for Wood Containing Bark Beetle Pheromones and Blue-Stain Fungi

Surprisingly little research has been conducted to investigate interactions between subterranean termites and bark beetles. Facilitative interactions between these organisms could easily alter stand dynamics and impact wood utilization strategies. A series of American Wood Protection Association Standard E1-09 “choice tests” were carried out to determine the feeding preference of Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae) for blue-stained sapwood and sapwood impregnated with various bark beetle pheromones. Reticulitermes flavipes exhibited a feeding preference for both air-dried and kiln-dried blue-stained sapwood, unstained sapwood treated with frontalin, and air-dried blue-stained sapwood treated with a 0.02% solution of both frontalin and endo-brevicomin. The implications of these results are far reaching, with particular relevance to forest health, ecology, and utilization.     

Influences of Forest Structure on the Density and Habitat Preference of Two Sympatric Gibbons (Symphalangus syndactylus and Hylobates lar)

International Journal of Primatology - Forest structure, defined as the three-dimensional vertical and horizontal distribution of canopy vegetation, has a great influence on the distribution...     

Effect of Season and High Ambient Temperature on Activity Levels and Patterns of Grizzly Bears (Ursus arctos)

Understanding factors that influence daily and annual activity patterns of a species provides insights to challenges facing individuals, particularly when climate shifts, and thus is important in conservation. Using GPS collars with dual-axis motion sensors that recorded the number of switches every 5 minutes we tested the hypotheses: 1. Grizzly bears (Ursus arctos) increase daily activity levels and active bout lengths when they forage on berries, the major high-energy food in this ecosystem, and 2. Grizzly bears become less active and more nocturnal when ambient temperature exceeds 20°C. We found support for hypothesis 1 with both male and female bears being active from 0.7 to 2.8 h longer in the berry season than in other seasons. Our prediction under hypothesis 2 was not supported. When bears foraged on berries on a dry, open mountainside, there was no relationship between daily maximum temperature (which varied from 20.4 to 40.1°C) and the total amount of time bears were active, and no difference in activity levels during day or night between warm (20.4–27.3°C) and hot (27.9–40.1°C) days. Our results highlight the strong influence that food acquisition has on activity levels and patterns of grizzly bears and is a challenge to the heat dissipation limitation theory.     

Thermal Preference of Juvenile Dover Sole (Solea solea) in Relation to Thermal Acclimation and Optimal Growth Temperature

Dover sole (Solea solea) is an obligate ectotherm with a natural thermal habitat ranging from approximately 5 to 27°C. Thermal optima for growth lie in the range of 20 to 25°C. More precise information on thermal optima for growth is needed for cost-effective Dover sole aquaculture. The main objective of this study was to determine the optimal growth temperature of juvenile Dover sole (Solea solea) and in addition to test the hypothesis that the final preferendum equals the optimal growth temperature. Temperature preference was measured in a circular preference chamber for Dover sole acclimated to 18, 22 and 28°C. Optimal growth temperature was measured by rearing Dover sole at 19, 22, 25 and 28°C. The optimal growth temperature resulting from this growth experiment was 22.7°C for Dover sole with a size between 30 to 50 g. The temperature preferred by juvenile Dover sole increases with acclimation temperature and exceeds the optimal temperature for growth. A final preferendum could not be detected. Although a confounding effect of behavioural fever on temperature preference could not be entirely excluded, thermal preference and thermal optima for physiological processes seem to be unrelated in Dover sole.     

Common names for Australian ants (Hymenoptera: Formicidae)

Abstract Most insects do not have common names, and this is a significant barrier to public interest in them, and to their study by non-specialists. This holds for even highly familiar insect groups such as ants. Here, I propose common names for all major native Australian ant genera and species-groups, as well as for many of the most abundant and distinctive species. Sixty-two genera, 142 species-groups and 50 species are given names. The naming system closely follows taxonomic structure; typically a genus is given a general common name, under which species-group and species names are nested.     

Influences of Temperature and Desiccation on Breaking Diapause in the Gemmules of Eunapius fraqilis (Leidy)

Summary

Most specimens of Eunapius fraqilis in Gallup Pond (Connecticut) apparently formed gemmules in September and then died. The gemmules were initially in a protracted diapause which was gradually broken during the winter. They germinated in the pond between late March and late April. Gemmules collected during the fall did not germinate during four months when they were kept at 20°C. Other gemmules from the same collections, which were kept at 5°C for several months before they were placed at 20°C, exhibited good germination. Finally, gemmules that did not germinate following a cold treatment could be activated by drying them at 20°C for seven days and then maintaining them in pond water at 20°C. These results suggest that low temperature and desiccation are effective in breaking gemmule diapause of Eunapius fraqilis.     

Interaction Effects of Seed Mass and Temperature on Germination in Australian Species of Frankenia (Frankeniaceae)

The seed size and number theories have been proposed to explain the advantages of having many small versus a few large seeds in plants. In particular, seed germination is predicted to be shaped by temperature, and may differ for small and large seeds. In this study, we experimentally test germination at different temperatures in 12 species of arid zone plants in the genus Frankenia L. that differ in seed mass. Seed mass was categorized as “smaller-seeded species” versus “larger-seeded species” for analysis (six species per category). Many of these species co-occur geographically and hence experience similar abiotic conditions (unpredictable rainfall, extremes in temperature, poor soil conditions). The results demonstrated differences in germination as a result of the temperature*seed mass(species) interaction effect. There were significant differences in germination rates across seed mass categories during the first eight days of germination. Germination rates were higher in the larger-seeded species than the smaller-seeded species. Smaller-seeded species had lower germination success but had higher germination rates at lower temperatures, and had a more stringent temperature as a germination cue. These findings are discussed in the context of life-history strategies in arid zone plants.     

Taste Preference Thresholds for Food-Associated Sugars in Baboons (Papio hamadryas anubis)

We aimed to determine taste preference thresholds for 5 food-associated sugars in Papio hamadryas anubis. In a 2-bottle preference test of brief duration (2 min) 4 subadult baboons significantly preferred concentrations as low as 10 mM sucrose, 20 mM fructose, lactose, and maltose, and 25 mM glucose over tap water. Presentation of suprathreshold sugar solutions led to marked concentration-dependent polydipsia. The results show that baboons are among the most sugar-sensitive nonhuman primates tested so far and, thus, support the assumption that Papio hamadryas anubis may use sweetness as a criterion for food selection.