Dispersion distance of queens from natal sites in the two haplometrotic paper waspsPolistes riparius andP. snelleni (Hymenoptera: Vespidae)

Dispersion capabilities of new queens were studied in the two haplometrotic paper wasps Polistes riparius and P. snelleni. New queens were marked on the nests in the late summer and located in the next spring. Dispersion distances greatly varied among queens: although a large part of recovered queens nested in close proximity to their natal sites, some did disperse over 100–300 m. This suggests that queens' emigration from and immigration into the censused areas occurred to a substantial extent. On the whole, these species exhibited a weaker “philopatric” tendency than those so far studied for dispersion distance, and seem to have the potential for a long-distance dispersion.     

Seasonal change of nest survival and related aspects in an aggregation ofLasioglossum duplex (Dalla torre), a eusocial halictine bee (Hymenoptera: Halictidae)

Nest survival in an aggregation of a eusocial halictine bee, Lasioglossum duplex, was censused through an annual cycle. Out of 2,500 nests marked at the beginning of solitary phase in the spring, only 25.5% attained eusocial phase. But 60.5% of 636 nests attaining eusocial phase successfully produced sexual offspring. This shows that solitary phase is the most vulnerable period in the annual cycle. A very low productivity in eusocial phase in the census year was clarified from examination of 99 nests in the autumn. The number of prospective foundresses surviving to the next year was estimated upon the number of brood cells in examined nests and of old females surviving these nests. Deviation between this estimate and the number of nests made in the next spring was 8.8%, confirming a drop of population size to less than one third in the next year. Some nests solitarily made in the summer by dispersed females were examined. Productivity in such nests was extremely low, hence these nests should contribute virtually nothing to the next generation. Possible factors affecting the low productivity in eusocial phase were enumerated though none of these were supported by concrete evidence. Some considerations were given on the relation between obtained results and colony life cycle in eusocial insects, particularly in halictine bees.     

Nesting biology of tropical solitary and social sweat bees,Lasioglossum (Dialictus) figueresi Wcislo andL. (D.) aeneiventre (Friese) (Hymenoptera: Halictidae)

Summary The nesting biology of a mainly solitary bee,Lasioglossum (Dialictus) figueresi, is compared with that of a possible relative and mainly eusocial bee,L. (D.) aeneiventre. These bees nest in the ground in highly disturbed areas in the Meseta Central of Costa Rica. Information is provided on social organization, male production, diel and seasonal activity patterns, pollen utilization, natural enemies and nest architecture. L. (D.) figueresi nests within aggregations in vertical earthen banks, and 80–90 % of females are solitary during the nest-provisioning phase. Social nests contain two (or rarely three) females which may be either equal or unequal in reproductive status (i.e. mated with developed ovaries or not). Solitary nests and two-female nests do not experience different rates of parasitism. Mid-way through the dry season, females cease provisioning at a time when otherL. (Dialictus) remain active. Females typically remain within their nests, although they occasionally forage for nectar. This behavior is similar of that of spring gynes of temperate eusocial species. The egg-to-adult developmental rate ofL. (D.) figueresi is unusually slow for halictine bees, however, so that all the adult females die before their brood eclose in April and May, precluding overlap of generations. The eclosed offspring remain in open cells within their natal nests until mid-June, when both males and females emerge to mate. These newly mated females either establish new nests or re-use old ones. L. (D.) aeneiventre nests within aggregations in horizontal ground or in vertical banks. A foundress female digs a nest at the beginning of the dry season, although some re-activate old nests. Foundress nests develop into colonies with various kinds of social organization. In contrast toL. (D.) figueresi, L. (D.) aeneiventre is active nearly all year round, except during periods of heavy rain, and produces up to three broods per year.Sweat bees (Hymenoptera: Halictinae) are a socially heterogeneous group of mainly ground-nesting bees which are abundant world-wide. Intra-specific variation in social behavior is prevalent both within and among populations, presumably indicating social and environmental control of behavioral modifications (see e.g. Sakagami and Munakata, 1972; Eickwort, 1986; Packer, 1990; Yanega, 1988; reviewed in Michener, 1990). The initial stages of hymenopteran social evolution are represented by solitary individuals and those in undifferentiated societies, yet their biology is not well known, as is true for the numerous tropical halictine species or populations (see Michener, 1990).The subgenusDialictus ofLasioglossum is a primarily New World group of several hundred species (Moure and Kurd, 1987). These bees are monotonously similar in structure and appearance, yet diverse in social behavior. FemaleLasioglossum (Dialictus) figueresi are usually solitary, and structurally are very similar to their social relativeL. (D.) aeneiventre (Wcislo, 1990 a). The systematic placement of these species with respect to otherL. (Dialictus) is uncertain, but they have no obvious affinities to other recognized species groups (G. C. Eickwort, pers. comm.). Unusual morphological features, such as large size, yellowish wings and pubescence, and features of the genital organs, may indicate thatL. (D.) figueresi is the more derived of the pair, and may therefore be secondarily solitary, as is known for other sweat bees (Packer, 1991).     

Seasonal changes in ovarian state in a eusocial halictine bee,Lasioglossum duplex,based on stages of the oldest oocytes in each ovariole (Hymenoptera: Halictidae)

Summary The changes in ovarian activity in the life cycle of the eusocial halictine beeLasioglossum (Evylaeus) duplex (Dalla Torre) was studied in both queens and workers by examining the stages of the terminal follicle in each of the six ovarioles. By this method, ovarian activities of both queens and workers were more quantitatively determined than by observation of gross ovarian features as usually conducted. Queen ovaries clearly exhibited two active periods, corresponding to the spring solitary phase and the summer eusocial phase, with distinctly greater activity in the latter. In ovaries of overwintering queens oosorption of young follicle was observed. Worker ovaries were found more active in orphan than in queenright colonies. The order of ovarian activity obtained from pooled data, summer queens>spring queens>orphan workers>queenright workers, was also recognized by comparison of individual females. Bionomics of the eusocial halictine beeLasioglossum duplex IX. Contribution No. 3107 from the Inst. Low Temp. Sci.     

Patterns of provisioning and iteroparity in a solitary halictine bee,Lasioglossum (Evylaeus) fratellum (Perez), with notes onL. (E.) calceatum (Scop.) andL. (E.) villosulum (K.)

Summary On Dartmoor, UK the temperate halictine beeLasioglossum (Evylaeus) fratellum is solitary and univoltine. A significant proportion of individually marked foundresses reproduce during two different seasons (iteroparity). This could represent a form of risk-spreading in environments where conditions are harsh and unpredictable. Perhaps associated with iteroparity, foundresses put in relatively low reproductive effort, often failing to provision their nests on suitable days, despite the small number of days available on Dartmoor. Foundresses stopped provisioning asynchronously, then remained in their nests until well after offspring emergence. There was a small proportion of digynous nests, in which nest-sharing appeared to be temporary.L. (E.) calceatum had a similar life-cycle on Dartmoor.L. villosulum was also solitary, and was able to provision its nests under less favourable weather conditions than the other two species. Information is also provided on nest productivity andSphecodes parasites.     

Local distribution of two swallows of genusHirundo,and breeding success ofH. rustica

Population Ecology - The distribution of nests of the swallows was investigated in 1957, 1962 and 1963 at Koriyama, Nara Prefecture. Roughly speaking, the nest ofHirundo rustica was located in the...     

Breeding ecology and male spawning success in two hill-stream populations of the freshwater goby,Padogobius martensi

Synopsis This investigation was carried out at two study sites to examine the influence of shelter availability, nest site quality and male body size on spawning success of malePadogobius martensi. At Stirone Stream (first study site) individuals were not randomly distributed with respect to usable stones; larger males and females were consistently found to occupy larger stones. Laboratory experiments showed that the bottom surface area of the shelter was the relevant cue for the choice. The number of nesting males settled in a given area increased with increasing availability of local stone cover; inter-nest distance was directly correlated with male size. At Rivarolo Stream (second study site), which was characterized by lower nest density and a greater shortage of large stones, the pattern of shelter occupation was similar. These results suggest the presence of competition among individuals for the possession of larger-sized shelter sites. At both sites, the number of eggs in the nest increased as stone size increased; however, at the first study site, male body size played a major role in male spawning success as it concerns both the numbers of females mated and the number of eggs, while at the second study site, male body size was not shown to influence male spawning success. Factors responsible for between-site differences in male spawning success are discussed.     

Diel changes of temperature in the nests of two Polybia species, P. paulista and P. occidentalis (Hymenoptera, Vespidae) in the subtropical climate

Temperatures in two mature Polybia nests were measured to study the thermal conditions of nests. Temperatures in a Polybia paulista nest were measured when it had adult wasps (trial 1) and after the adult wasps were removed (trial 2), and temperatures in a P. occidentalis nest were measured when inhabited by adult wasps (trial 3). In each trial, C–C thermocouples were set at four points in the nest and at two points outside to discover the ambient and substratum temperatures. In trial 1, nest temperatures basically followed the ambient temperature, but during the day the nest temperatures were lower than the ambient temperature and this relationship was reversed during the night. The temperature fluctuation of the inner substratum points was smaller than that of the outer points. The trend of trial 2 was closely similar to that of trial 1, showing a virtual lack of thermal effects from the presence of adult wasps. In trial 3, the changing pattern in the P. occidentalis nest showed a trend similar to that in the P. paulista nest, but the inside temperatures rose quickly when the nest received direct sunlight in the morning. From these results, thermal characteristics in the Polybia nests are discussed in relation to the nest architecture and their geographical distribution.     

Differences in winter activity,courtship, and social behavior of two captive family groups of Mexican wolves (Canis lupus baileyi)

The purpose of this study was to determine differences in activity patterns and social behavior of two groups of endangered Mexican wolves maintained at two quite different facilities and to determine some of the variables that should be considered when making specific behavioral comparisons among wolves in this binational captive breeding program. Quantitative measurements of an Activity Index and social behaviors were obtained for three individuals in each pack. Within each age/sex category, activity, aggression, and play were more frequent in the pack at a zoo facility, compared to the pack at a field station facility. Frequency of courtship interactions and scent marking were significantly higher in the field station pack. The packs were similar in the frequency of active submission, but differed significantly in the pattern of this behavior. Given the large number of interacting variables and small number of individuals in this study, we recommend caution in generalizing results to other packs or facilities. Zoo Biol 16:435–443, 1997. © 1997 Wiley-Liss, Inc.     

The ecology of a beech forest on Mt. Sanpoiwadake,Hakusan National Park,Japan II. The correlation of the subassociation within the Lindero membranaceae-fagetum crenatae association and environmental parameters

Detailed examination of a sample plot covered by the Lindero membranaceae-Fagetum crenatae association on Mt. Sanpoiwadake, Hakusan National Park, revealed a number of correlations between the distribution of subassociations and environmental factors. The subassociations on the south-facing slopes receive deep snow cover in winter with rapid melting in the spring. They occur on porous, freely draining soils, typical of the general range of brown forest soils. Conversely, on the north-eastern slopes there are widespread late-snow patches which delay leaf development and expansion and which provide an abundant water supply well into early summer. Under these conditions, bleached soil horizons have developed with iron pan formation, resulting in poor soil drainage, strongly correlated with quite different plant communities.     

Nest recognition in neighboring colonies: a comparison of two European species of Polistes wasps (P. dominulus and P. nimphus, Hymenoptera: Vespidae)

The ability of two species of Polistes wasps to distinguish their own from nearby nests was tested, following the procedure used by Espelie et al. Our experiments demonstrated that, in the laboratory, females of Polistes dominulus and Polistes nimphus preferentially selected their own nests rather than nearby nests. We also evaluated the role of odor cues in nest recognition by washing nests in hexane to remove the apolar solvent-soluble components of nest odor. Although P. nimphus females continued to discriminate nests even after washing, P. dominulus individuals failed to discriminate between their own and a foreign neighboring nest. In both species, wasps were able to recognize their own nests when nest extracts were subsequently reapplied to the nest surface. These results indicate that P. dominulus wasps recognize their nests through perception of nest odor. The ability of P. nimphus wasps to distinguish their own nests even after presumed removal of the nest odor is discussed. Received: January 27, 2000 / Accepted: May 22, 2000     

Effect of population density on reproduction of two sympatric dung beetle species,Aphodius haroldianus andA. Elegans (Coleoptera: Scarabaeidae)

The effect of population density on reproduction as well as the oviposition modes of two sympatric dung beetle species, Aphodius haroldianus (a low fecundity/high parental effort species) and A. elegans (a high fecundity/low parental effort species) was studied at a pasture in central Japan from 1982 to 1986.

1. The adult population density of A. haroldianus was high (>40 per dung pat). The density of A. elegans was low (<5 per dung pat). Oviposition of A. haroldianus was suppressed above the density of about 10 adults of conspecifics but not affected by the density of other species. The intra- and interspecific density effects on oviposition were not detected in A. elegans.
2. The number of A. haroldianus adults per pat decreased with dung age, while that of A. elegans increased until sixth day after deposition and then decreased. The number of eggs laid per pat was not different between 1-day-and 3-day-old pats for A. haroldianus. However, more eggs of A. elegans were found in 3-day-old pats than in 1-day-old ones.
3. In the both species, the amplitude of population fluctuations was not remarkable; the maximum/minimum ratio for five years being 2.3 for A. haroldianus and 2.9 for A. elegans. Different density dependent processes were suggested to function for the small fluctuation of population density between the two species, i.e. intraspecific density effect on oviposition for A. haroldianus and contest type competition for food among larvae of A. elegans.

     

Phytophthora species isolated from alpine and sub-alpine regions of Australia,including the description of two new species; Phytophthora cacuminis sp. nov and Phytophthora oreophila sp. nov

Plant deaths had been observed in the sub-alpine and alpine areas of Australia. Although no detailed aetiology was established, patches of dying vegetation and progressive thinning of canopy suggested the involvement of root pathogens. Baiting of roots and associated rhizosphere soil from surveys conducted in mountainous regions New South Wales and Tasmania resulted in the isolation of eight Phytophthora species; Phytophthora cactorum, Phytophthora cryptogea, Phytophthora fallax, Phytophthora gonapodyides, Phytophthora gregata, Phytophthora pseudocryptogea, and two new species, Phytophthora cacuminis sp. nov and Phytophthora oreophila sp. nov, described here. P. cacuminis sp. nov is closely related to P. fallax, and was isolated from asymptomatic Eucalyptus coccifera and species from the family Proteaceae in Mount Field NP in Tasmania. P. oreophila sp. nov, was isolated from a disturbed alpine herbfield in Kosciuzsko National Park. The low cardinal temperature for growth of the new species suggest they are well adapted to survive under these conditions, and should be regarded as potential threats to the diverse flora of sub-alpine/alpine ecosystems. P. gregata and P. cryptogea have already been implicated in poor plant health. Tests on a range of alpine/subalpine plant species are now needed to determine their pathogenicity, host range and invasive potential.     

Social and ecological contexts of trophallaxis in facultatively social sweat bees, Megalopta genalis and M. ecuadoria (Hymenoptera, Halictidae)

Exchange of liquid food among adults (trophallaxis) is documented for the first time in New World sweat bees (Halictinae). Megalopta genalis and M. ecuadoria are facultatively social, and in social groups foragers regularly give food to the oldest resident female bee, which dominates social interactions. In turn, the oldest resident sometimes re-distributes this food, and shares it with younger foragers. Food is sometimes offered freely, but often the dominant bee exhibits escalating aggressive behavior until she is fed, whereupon she immediately ceases to be aggressive. The occurrence of trophallaxis in a species with mass-provisioned larvae provides an opportunity to examine the ritualization of social behavior. Trophallaxis also increases survivorship of males and females by almost 50% under experimental conditions, suggesting the behavior is also important in ecological contexts. Received 25 July 2005; revised 22 November 2005; accepted 23 December 2005.     

Of mites and bees: A review of mite–bee associations in Australia and a revision of Raymentia Womersley (Acari: Mesostigmata: Laelapidae), with the description of two new species of mites from Lasioglossum (Parasphecodes) spp. (Hymenoptera: Halictidae)

Social bees have a diverse fauna of symbiotic mesostigmatic mites, including highly pathogenic parasites of the honeybee, but there are few reports of Mesostigmata phoretic on or inhabiting the nests of solitary or communal, ground-nesting bees. In south-eastern Australia, however, native bees in the family Halictidae carry what appears to be a substantial radiation of host-specific mesostigmatans in the family Laelapidae. Herein, we redescribe the obscure genus Raymentia , associated with Lasioglossum ( Parasphecodes ) spp. bees (Halictidae) and describe two new species, R. eickwortiana from L. lacthium (Smith) and R. walkeriana from L. atronitens (Cockerell). The type species, R. anomala Womersley, is associated with L. altichum (Smith). In addition, we review the mites known to be associated with Australian bees, provide a key to differentiate them, and describe and illustrate acarinaria of the Halictinae. We also report on the first occurrences in Australia of the genera Trochometridium Cross (Heterostigmata: Trochometridiidae), from L. eremaean Walker (Halictidae), and Cheletophyes Oudemans (Prostigmata: Cheyletidae) from Xylocopa Latreille (Xylocopinae), and on the previously unknown association between a Neocypholaelaps Vitzthum (Mesostigmata: Ameroseiidae) and Lipotriches tomentifera (Friese) (Halictidae).     

The behavioral ecology of three Indian Ocean surgeonfishes (Acanthurus lineatus,A. leucosternon and Zebrasoma scopas): their feeding strategies,and social and mating systems

Synopsis The relationship between the morphology, feeding strategies and social and mating systems of three surgeonfishes was investigated. Adults of each defend feeding territories, intra-and interspecifically. The largest species, because of its morphological limitation, relies on food that has to be defended against many other species. It forms large colonies in which fishes singly defend small territories containing high standing crop algal mats. Colony formation is a mechanism by which the efficiency and effectiveness of interspecific territory defense is increased. The smallest species, because of its morphological adaptations, is able to rely most on food that other species cannot efficiently exploit. It forms pairs that defend large territories containing a thin algal mat. It is restricted to the poorest quality habitat by the aggressive activities of more dominant species. The third species, which also forms pairs, has an intermediate feeding strategy. The local coexistence of these three and other surgeonfishes results from a combination of (i) their partitioning both habitat and food resources, and (ii) the populations of two of the most dominant species apparently being below the carrying capacity. Territoriality and the absence of parental care facilitates pair formation in surgeonfishes. Permanently territorial species usually form pairs. The colonial species does not form pairs because the colonial habit facilitates interference of males in each other's spawnings.     

西班牙桉树林下土小平盘菌复合群中两个独立的种——暗柔膜菌属一新组合及一新种:分类、分子生物学、生态与分布(英文)

土小平盘菌复合群原产澳大利亚,其中两个土生种在西班牙报道,很可能是在18世纪中叶引入西班牙。根据形态学特征和序列分析的结果,建立一个新组合和一个新种,分别定名为Phaeohelotium undulatum comb.nov.和Phaeoh.succineoguttulatum sp.nov.。对其宏观和微观形态特征进行了详尽的描述和图示,ITS rDNA序列分析的结果显示,它们以100%的支持率与Phaeohelotium monticola聚类在同一个分支。文中提供了该复合群Phaeohelotium属5个土生种的分种检索表,并对它们的生态习性与世界分布进行了深入讨论。