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Summary Distribution, host preference and pathogenicity of Japanese Armillaria species on conifers were investigated on the basis of field collections of 65 isolates. We identified seven Armillaria species from 19 conifer species including six major Japanese plantation conifers using mating tests and sequences of the translation elongation-1 α gene. Armillaria mellea, Armillaria ostoyae, Armillaria cepistipes and Armillaria sinapina were frequently collected, whereas Armillaria nabsnona, Armillaria tabescens and a biological species Nagasawa's E were rare. On the basis of host condition when the isolates were collected, A. mellea, A. ostoyae, A. cepistipes and A. tabescens are considered as moderate to aggressive pathogens of conifers in Japan. [ABSTRACT FROM AUTHOR]

How cooperation can arise and persist, given the threat of cheating phenotypes, is a central problem in evolutionary biology, but the actual significance of cheating in natural populations is still poorly understood. Theories of social evolution predict that cheater lineages are evolutionarily short-lived. However, an exception comes from obligate socially parasitic species, some of which thought to have arisen as cheaters within cooperator colonies and then diverged through sympatric speciation. This process requires the cheater lineage to persist by avoiding rapid extinction that would result from the fact that the cheaters inflict fitness cost on their host. We examined whether this prerequisite is fulfilled, by estimating the persistence time of cheaters in a field population of the parthenogenetic ant Pristomyrmex punctatus. Population genetic analysis found that the cheaters belong to one monophyletic lineage which we infer has persisted for 200-9200 generations. We show that the cheaters migrate and are thus horizontally transmitted between colonies, a trait allowing the lineage to avoid rapid extinction with its host colony. Although horizontal transmission of disruptive cheaters has the potential to induce extinction of the entire population, such collapse is likely averted when there is spatially restricted migration in a structured population, a scenario that matches the observed isolation by distance pattern that we found. We compare our result with other examples of disruptive and horizontally transmissible cheater lineages in nature. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the prevalence of antiphospholipid antibodies, mainly anti-β2-glycoprotein I (anti-β2-GPI), and their possible clinical and laboratory relevance in mixed connective tissue disease (MCTD). This study included 39 consecutive patients with MCTD (Kasukawa's criteria) from January, 2005, to March, 2007, and compared them with 21 age- and sex-matched healthy controls. IgG and IgM anticardiolipin (aCL) and anti-β2-GPI were measured by ELISA. Lupus anticoagulant (LA) was detected by functional coagulation tests. Medium to high titres of aCL and anti-β2-GPI antibodies were found in sera from four (10.2%)MCTD patients. One of these patients was found to be positive for IgM aCL, IgM anti-β2-GPI and LA antibodies simultaneously. Additionally, this patient had a previous history of foetal loss in the second trimester and new-onset pulmonary arterial hypertension (PAH). The other three patients had none of the manifestations of antiphospholipid syndrome (APS) or PAH. The mean value of IgG anti-β2-GPI was higher among those MCTD patients with PAH than in the group without PAH (34.2 ± 46.8 vs 12.3 ± 9.1, P = 0.018). None of the controls were positive for antiphospholipid antibodies. High to moderate titres of anti-β2-GPI as well as APS were rare in MCTD, and these antibodies may be correlated with the development of PAH in these patients. [ABSTRACT FROM AUTHOR]

Hynobius retardatus has a head-width plasticity that is functional in cannibalism and preying on large creatures. Cannibalistic specialization in H. retardatus appears to a lesser degree than in those species that have clearly dimorphic morphs. To examine the degree of cannibalistic specialization and intraspecific phenotypic variation, we investigated the allometric relationship between the head and body in the larvae of H. retardatus in a single pond. In addition, the effect of cannibalism on the determination of morphology was examined. A field survey revealed the existence of allometric dimorphism and the occurrence of large-headed large larvae. However, we did not observe a bimodal size distribution that indicates a split in the population. A laboratory experiment revealed that the development of such large-headed large larvae was inducible by actual cannibalism and/or additional tactile cues under high-density conditions. We deduce that the allometric dimorphism in the larvae of H. retardatus in the wild is caused by actual cannibalism. The cannibalistic phenotypic variation in H. retardatus would be characterized by allometric dimorphism without a bimodal size-frequency distribution. [ABSTRACT FROM PUBLISHER]

Genotypes of a queen and the first brood of workers of 20 colonies of Polistes chinensis antennalis were electrophoretically analyzed. We found allelic polymorphisms in two loci which encodes two enzyme, i.e., creatine kinase (CK) and isocitrate dehydrogenase (IDH). The genotype array of the first brood of workers in five colonies could not be explained by monoandry of the queen. Two to four suggested multiple mating of the queen, and one to three suggested replacement of the queen. Although multiple matings of some queens is apparent, the mean estimate of relatedness of the first brood of workers from the genotype frequency data, 0.648, is ambiguous, because it is not significantly different from 0.75 (one singly-mated queen) nor 0.545 (one doubly-mated queen). [ABSTRACT FROM PUBLISHER]

Previously known parent-offspring relationship for queens and her daughters of the ant Colobopsis nipponicus was examined using RAPD markers in order to test the reliability of this molecular technique for estimating the reproductive structure within colonies of social insects. RAPD markers from 20 oligomers successfully clustered the queen with her daughters among an artificially generated polygynous society, even when paternal information was unavailable. When information from both the queen and her sperm was included in the analysis, 20 polymorphic bands seem to be sufficient to cluster correctly the true parents to their offspring. Lack of father's information considerably decreased accuracy of the analysis. Thus, if RAPD markers are to be used to demonstrate parent-offspring relationship between individuals in the field, sperm from the queen's spermatheca should be incorporated in analysis. [ABSTRACT FROM AUTHOR]

The present paper describes for the first time that adult-to-adult trophallaxis exists in ponerine ants. Furthermore, it shows that the adult castes of the ponerine and Hypoponera sp. have different habits of trophallaxis. Workers display a soliciting behavior toward queens, males and workers, but receive regurgitated food only from workers. The workers are forced to stop soliciting for regurgitated food by the 'whipping behavior' of the queen. Callow queens solicit regurgitated food from workers and ergatoid males and receive it, while mature queens do not solicit regurgitation from workers. Ergatoid males receive regurgitated food from workers and regurgitate it to queens. Alate males show no trophallactic food exchange with workers and queens. Trophallactic behavior was never observed between males of either winged or ergatoid types. [ABSTRACT FROM AUTHOR]

Intercolonial differences in raiding activity were investigated in the field on 9 colonies of the slavemaking ant Polyergus samurai. Duration of raiding season, the mean start time of the first raiding trip in a day, the mean speed of outbound and inbound trips, and the mean distance to target nests varied significantly among colonies. The variance in start time of raiding was correlated with that in soil temperature and diurnal change pattern in soil temperature at the nest sites. The speed of trips and the first day with trips in the season also correlated with soil temperature at the nest site. Simple environmental factors well explained the observed variances in raiding activity among colonies. Therefore, raiding behaviour of P. samurai seemed to be a stereotyped behaviour that is regulated through simple environmental factors. [ABSTRACT FROM AUTHOR]

Raiding behavior of the Japanese slave-making ant Polyergus samurai was investigated in the field. Raiding trips occurred from early June to early September. A raiding column of several hundreds workers would rush into a target nest and rob mainly worker pupae of the host species, Formica (Serviformica) japonica. Most trips occurred on sunny days. Air temperature, soil temperature, relative humidity, and radiation energy at the ground surface were significantly different between days with and without raiding trips. Nuptial flights occurred on hot, sunny days, and most Polyergus colonies released alates simultaneously. Behaviors of newly mated queens are also provided and are compared with other Polyergus species. [ABSTRACT FROM AUTHOR]

Life history parameters, including colony boundary, number of queens in a colony, seasonal change in colony-member composition and seasonal change in male-egg production were investigated for the arboreal ant Colobopsis nipponicus in the field. Colonies were shown to be typically monogynous and polydomous, with several different colonies inhabiting the same tree. The queen and workers overwinter only with larvae, which grow rapidly into new adults during early summer. Male-destined eggs were produced throughout the warm season with a conspicuous peak in summer that coincided with adult production. It is suggested that this might be related to seasonal changes in the food available to the queen. [ABSTRACT FROM AUTHOR]

Food-storage abilities of both minor and major workers of the dimorphic ant Colobopsis nipponicus were examined to prove the hypothesis that major workers of this species have a trophic role in addition to a defensive one. Both worker subcastes accumulated water, that was supplied with water-soluble food, as well as fat, that probably originated from food given. However, the major workers accumulated much larger amounts of water and fat than did the minor workers. Difference in water accumulation increased as food supply increased. In spite of their difference in body weight, the residual amount of fat after starvation did not differ between the two subcastes. Although the amount of stored fat increased with colony size in both subcastes, the stored fat per dry weight of the major worker was significantly larger than that of the minor worker regardless of the colony size. When workers of a colony were starved, minor workers with a single major worker survived significantly longer than those without a major worker. In addition, about half the behavioral acts of major workers were regurgitation for minor workers. These results demonstrate that major workers of C. nipponicus functioned as a trophic caste. On the basis of the results, quantitative relationships of storage abilities between the two worker subcastes are discussed. [ABSTRACT FROM AUTHOR]