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Pseudoscorpions are predators of arthropods and primarily inhabit soil litter and tree bark in forests, although some species have been collected from animal nests, suggesting close associations with mammals and birds. We made preliminary observations on the life cycle and life history traits of Megachernes ryugadensisMorikawa, 1954, phoretic on the wood mice Apodemus speciosus and A. argenteus, by sampling wild specimens in the field and rearing these specimens in a laboratory. The main phoretic host at the study site was A. speciosus; we observed an average of 1–1.7 pseudoscorpions on 5–36% of mice within the 2-year study period. The observed phoretic stages of M. ryugadensis were adults and tritonymphs; the phoretic ratio on A. speciosus was relatively stable for 2 years. The duration of full development from egg to adult in M. ryugadensis was unclear, probably due to unsuitable rearing conditions; however, individuals survived as adults for over one year. Typical maternal care was confirmed in pseudoscorpions and egg hatching was synchronized to within ca. 8 h. Further study, including close examination of mouse nests, is required to elucidate the symbiotic relationship between the pseudoscorpion and host rodents.

Ovary contents and insemination status were examined in overwintered queens of Vespa mandarinia that were collected using bait traps in Ibaraki Prefecture, eastern Japan. Catches in the traps occurred from late April to early July in 1999, though they were few or rather sporadic in and after June. Fertilization rates were 100% in 1999, and 93% in 1998 when a preliminary sampling was made. While the ovary index (number of eggs with size equal to or larger than adjacent nurse cells) of queens caught on the first few collection dates was small, it rapidly increased up to late May. Generalized linear model analyses showed that the ovary index depended both on collection date and the size (head width) of the queens. Mature eggs were almost absent in their ovaries before early May, whereas more than 70% of the queens had one or more mature eggs on and after May 10, suggesting the onset of nesting in early May.

We constructed a hazard map for oak wilt disease in Yamagata and Fukushima Prefectures, Japan, based on a logistic regression model. Within the framework of a regression model, we incorporated data from previously damaged areas on vegetation type, geography and meteorology, and pest immigration. We evaluated the predictive power of the model using defoliation records within the same prefecture taken from the subsequent year. The results obtained for Yamagata Prefecture were highly predictive and we conclude that practical hazard maps can be constructed based on damage records from the previous year combined with other environmental data. The predictive value of the model was improved dramatically by incorporating an immigration effect. The model used to predict damage in Yamagata Prefecture was correct for only 46.7% of the actual damage in Fukushima Prefecture. Several difficulties were identified regarding the application of the model in other prefectures. Based on our results, we suggest that defoliation data should be collected quickly in the target area when constructing a localized regression model that includes immigration. Collection and organization of defoliation data could help to quickly draw up hazard maps before oak wilt disease begins to occur in a given year.

Although primary forests are important for biological conservation, the value of secondary forests for forest-dependent organisms needs to be evaluated when habitat restoration is required. We examined whether flower-visiting insects can use secondary forests as alternative habitats to primary forests. In particular, we compared assemblages of bees (Anthophila) and flower longhorn beetles (Lepturinae: Cerambycidae) in young secondary, mature secondary, and primary forests. Our results showed that more bee species were captured in primary and mature secondary forests than in young secondary forests, and flower longhorn beetle species were captured more frequently in primary forests than in mature and young secondary forests. Ordination showed that the communities in the three forest types were not statistically identical, which indicated that secondary forests cannot provide an absolute alternative habitat to primary forests for bees and flower longhorn beetles. However, the results also suggest that as secondary forests mature, more primary forest species would be able to use secondary forests as habitats. This implies that restoration from other land uses, such as monoculture plantations, to secondary forests could help to promote the faunal biodiversity of primary forests.

Since the 1960s, Japan has become highly dependent on foreign countries for natural resources, and the amount of managed lands (e.g. coppice, grassland, and agricultural field) has declined. Due to infrequent natural and human disturbance, early-successional species are now declining in Japan. Here we surveyed bees, birds, and plants in four human-disturbed open habitats (pasture, meadow, young planted forest, and abandoned clear-cut) and two forest habitats (mature planted forest and natural old-growth). We extended a recently developed multispecies abundance model to accommodate count data, and used the resulting models to estimate species-, functional group-, and community-level state variables (abundance and species richness) at each site, and compared them among the six habitats. Estimated individual-level detection probability was quite low for bee species (mean across species = 0.003; 0.16 for birds). Thirty-two (95% credible interval: 13–64) and one (0–4) bee and bird species, respectively, were suggested to be undetected by the field survey. Although habitats in which community-level abundance and species richness was highest differed among taxa, species richness and abundance of early-successional species were similar in the four disturbed open habitats across taxa except for plants in the pasture habitat which was a good habitat only for several exotic species. Our results suggest that human disturbance, especially the revival of plantation forestry, may contribute to the restoration of early-successional species in Japan.

Insular ecosystems can be dramatically affected by alien species, and records of pre-eradication status are essential to evaluate the effects of eradicating alien species. Nishi-jima Island is a small island of the Ogasawara group on which the first program of complete eradication of alien herbivorous mammals (black rats and feral goats) will be conducted. After eradication, the government plans to conduct ecosystem restoration on the island. This paper reports the angiosperm flora and vegetation of Nishi-jima Island before eradication of the rats and goats, with the objective of aiding ecosystem management after the eradication. Our surveys indicate that vegetation cover by the alien tree, Casuarina equisetifolia has expanded compared with its distribution in a 1974 aerial photograph of the island. The predominant vegetation in 2006 was C. equisetifolia forests and Zoysia tenuifolia grasslands, with fragmented native tree vegetation. The flora of the island comprised 69 angiosperm species (50 indigenous species) of which 30% were endemic, far less than for the Ogasawara Islands as a whole (45%). However, several populations of endangered plants remain. To restore the native ecosystem on Nishi-jima, eradication of C. equisetifolia is important in addition to eradication of alien herbivorous mammals.

Tube-nesting bees and wasps were collected with bamboo tube nest traps in a cherry blossom forest and an old secondary forest in Tama Forest Science Garden in the western suburbs of Tokyo. Curtain type traps, in which bamboo tubes were vertically arranged, attracted more bees and wasps to nests than bundle type traps, in which bamboo tubes were bundled haphazardly. The attractiveness of small tubes was similar between small tube traps, which were only composed of small tubes (about 4 mm in diameter), and size mixture traps, which set small tubes together with larger tubes, indicating that the presence of the larger species did not affect the nesting of small species. In the cherry forest, which was characterized by the sparse distribution of deciduous cherry trees with a thin canopy layer and rich growth of weeds, Megachilidae, Colletidae, Sphecidae and Eumenidae were common. In the shady secondary forest, where evergreen trees (Abies firma Sieb. et Zucc., Quercus glauca Thunb.) and shrubs (Aucuba japonica Thunb., Eurya japonica Thunb., Camellia japonica L.) were prevalent, Pompilidae was abundant. Among five species of Crabronidae recorded in this study, four were collected mostly in the cherry forest, whereas the most abundant, Trypoxylon malaisei Gussakovskij, was also common in the secondary forest. Likewise, Auplopus carbonarius (Scopoli) (Pompilidae) was common in the secondary forest and not rare in the cherry forest. These results suggest that the tube-nesting bees and wasps can be a good bioindicator for monitoring environment.

In this study, the influence of individual cuticular hydrocarbons on nestmate recognition in Japanese hornets was investigated. Cuticular hydrocarbons were extracted from the individuals of several colonies of Japanese hornets, Vespa analis Fablicius (Hymenoptera: Vespidae), and analyzed by combined gas chromatography and mass spectrometry (GC-MS). In the case of V. analis, the results of the GC-MS analyses showed 12 major components and 20 minor components. The results showed some intraspecific variation in the quantities of each component of the profiles even within the same colony and same cast. The number of cuticular hydrocarbon compounds of V. analis was relatively high compared with that of V. crabro. Discriminant analysis of the cuticular hydrocarbon profiles of the workers and queens showed that the wasps could be grouped by colony and by caste even if the colonies were located at a close distance. The cuticular hydrocarbon profiles of workers and males were different. Discipline: Insect pest Additional key words: Asian vespines, GC-MS analysis, nestmates recognition *Corresponding author: e-mail tokoro@affrc.go.jp Received 12 May 2010; accepted 15 November 2010.

Summary 1. In large-scale field surveys, a binary recording of each species’ detection or nondetection has been increasingly adopted for its simplicity and low cost. Because of the importance of abundance in many studies, it is desirable to obtain inferences about abundance at species-, functional group-, and community-levels from such binary data. 2. We developed a novel hierarchical multi-species abundance model based on species-level detection/nondetection data. The model accounts for the existence of undetected species, and variability in abundance and detectability among species. Species-level detection/nondetection is linked to species-level abundance via a detection model that accommodates the expectation that probability of detection (at least one individuals is detected) increases with local abundance of the species. We applied this model to a 9-year dataset composed of the detection/nondetection of forest birds, at a single post-fire site (from 7 to 15 years after fire) in a montane area of central Japan. The model allocated undetected species into one of the predefined functional groups by assuming a prior distribution on individual group membership. 3. The results suggest that 15–20 species were missed in each year, and that species richness of communities and functional groups did not change with post-fire forest succession. Overall abundance of birds and abundance of functional groups tended to increase over time, although only in the winter, while decreases in detectabilities were observed in several species. 4. Synthesis and applications. Understanding and prediction of large-scale biodiversity dynamics partly hinge on how we can use data effectively. Our hierarchical model for detection/nondetection data estimates abundance in space/time at species-, functional group-, and community-levels while accounting for undetected individuals and species. It also permits comparison of multiple communities by many types of abundance-based diversity and similarity measures under imperfect detection.

Crop pollination is an essential ecosystem service, which, when provided by wild pollinator species, can be negatively affected by human activities at a landscape scale. Various pollinator species can be affected by landscape factors and/or act at different spatial scales. We investigated whether different landscape factors at different spatial scales are correlated with pollinator abundances and pollination success. We examined common buckwheat, which is a self-incompatible crop species, pollinated by managed honeybees, native honeybees, and wild non-honeybee insects. To determine the effects of landscape factors at different spatial scales, we sampled flower-visiting insects and recorded seed sets. Results from the sampled flower visitors indicated that the abundances of managed honeybees, native honeybees, and wild non-honeybee insects were significantly related to the distance of managed hives, the area of forest cover within a 3-km radius, and the area of forest and grassland cover within a 100-m radius, respectively. Additionally, the latter two influential factors of the landscape, but not the distance of managed hives, showed significant positive correlations with the seed set. These results suggest that considering landscape factors at different spatial scales associated with the characteristics of managed and wild pollinators would help to ensure crop yields.

The alien predatory lizard, Anolis carolinensis, has reduced the insect fauna on the two main islands of the Ogasawara archipelago in Japan. As a result of this disturbance, introduced honeybees are now the dominant visitors to flowers instead of endemic bees on these islands. On the other hand, satellite islands not invaded by alien anoles have retained the native flower visitors. The effects of pollinator change on plant reproduction were surveyed on these contrasting island groups. The total visitation rates and the number of interacting visitor groups on main islands were 63% and 30% lower than that on satellite islands, respectively. On the main islands, the honeybees preferred to visit alien flowers, whereas the dominant endemic bees on satellite islands tended to visit native flowers more frequently than alien flowers. These results suggest that alien anoles destroy the endemic pollination system and caused shift to alien mutualism. On the main islands, the natural fruit set of alien plants was significantly higher than that of native plants. In addition, the natural fruit set was positively correlated with the visitation rate of honeybees. Pollen limitation was observed in 53.3% of endemic species but only 16.7% of alien species. These data suggest that reproduction of alien plants was facilitated by the floral preference of introduced honeybees.

1. Tree harvesting, an anthropogenic disturbance, and natural disturbances, such as avalanches, windstorms, fires, and floods, drive forest reestablishment. Chrono-sequential changes in plant communities as well as reforestation caused by harvesting and natural disturbances can affect forest faunal assemblages. 2. The effects of reforestation age, from recently harvested to old growth between 1 and 178 years old, on moth assemblages were examined for two types of reforestation: plantations and natural regeneration. 3. In total, 7848 individuals representing 579 species of moths were collected using black lights and then identified. In plantation forests, species richness and abundance responded unimodally to succession age, whereas in naturally regenerated forests, species richness and abundance did not significantly respond to succession age. In addition, the community structure of moth assemblages varied greatly in relation to succession age in both reforestation types. 4. These findings suggest that if the diversity of moth assemblages changes within and among forest stands of different successional stages, forest stands can provide habitat for unique moth assemblages. Thus, intentional forest management may enable the maintenance of greater moth diversity within a heterogeneous landscape or region. Various land-use practices, such as old growth forest conservation and short-length harvests, associated with forest types at the level of the forest stand could result in forest mosaics at the landscape or regional scale.

Despite plant quarantine systems, many organisms have been unintentionally introduced by the rapid expansion of international trade. Xylocopa tranquebarorum, a large species of carpenter bee that nests in bamboo shoots, was introduced into Japan approximately 5 years ago and, along with its specifically associated mite, has established populations in Toyota and Nagoya in Aichi Prefecture and Anpachi in Gifu Prefecture. Because X. tranquebarorum only nests in dead bamboo shoots and because its associated mite differs from the mite species associated with X. tranquebarorum in Taiwan but is morphologically similar to the species described in India, Indonesia, and China, we suspect that X. tranquebarorum and its mite were introduced via processed bamboo shoots from continental Asia. Because the most probable pathway of associated microorganisms is host introduction, biological and ecological information, such as an inventory of symbionts, is crucial to avoid the risk of invasive symbiotic microorganisms. Although X. tranquebarorum may become a pest in the bamboo industry if its distribution is expanded by human transport, its associated mite is suspected to be of low risk as house dust but to have a high contamination risk for the Japanese endemic mite, Sennertia alfkeni, associated with native Japanese carpenter bees.

The parasite Xenos moutoni inactivates workers and castrates reproductives of the Japanese hornet Vespa analis. Using over 500 nests, we investigated the relationship between hornet nest size (number of cells) and the proportion of parasitized adults (i.e., prevalence) in central Japan. Over 3 years, 36–48% of nests had more than one parasitized adult, and approximately 3–5% of female adults (mostly workers) and 1–3% of male adults were parasitized within the population. The number of cells did not differ between nests with and without parasitized workers; therefore, the effects of parasite-caused losses within the worker force on nest size appear to be negligible. However, the prevalence of parasitized workers tended to decrease with an increase in the number of cells. Our analysis indicated that the number of parasitized workers was consistently low and did not increase with nest size, resulting in a relatively high prevalence in small nests.

Crop pollination by animals is an essential ecosystem service. Among animal-pollinated crops, distylous plants strongly depend on animal pollination. In distylous pollination systems, pollinator species are usually limited, although flowers of some distylous plants are visited by diverse animals. We studied the pollination biology of common buckwheat (Fagopyrum esculentum), a distylous crop mainly pollinated by honeybees and visited by many insect species, to evaluate the effects of non-honeybee species on pollination services. We focused on insects smaller than honeybees to determine their contribution to pollination. We applied pollination treatments with bags of coarse mesh to exclude flower visits by honeybees and larger insects and compared the seed set of bagged plants with that of untreated plants for pin and thrum flower morphs. We found a great reduction of seed set only in bagged pin flowers. We also confirmed that small insects, including ants, bees, wasps and flies, carried pin-morph pollen. These small insects transfer pollen from the short anthers of pin flowers to the short styles of thrum flowers, leading to sufficient seed set in thrum flowers. Consequently, small, non-honeybee insects have the potential to maintain at least half of the yield of this honeybee-dependent distylous crop.

Natural forests are often replaced by invasive alien trees on isolated oceanic islands. Adequate eradication of invasive trees should be conducted with the goal of biodiversity conservation, because islands support many endemic organisms that depend on native forests. An invasive alien tree, Bischofia javanica Blume (Euphorbiaceae), has invaded and replaced natural forests on the oceanic Ogasawara (Bonin) Islands, Japan, in the northwestern Pacific Ocean. To determine how the removal of B. javanica trees affects insect diversity, we examined flying beetles captured using Malaise traps in B. javanica forests on Hahajima. The abundance, species density, and species composition of wood-boring beetles (Coleoptera: Cerambycidae, Elateridae, Mordellidae, and Scolytidae) were compared between closed-canopy sites and gaps created by girdling B. javanica trees in alien forests during two seasons (June–July and October–November 2005). Of the collected beetles, 75.8, 87.5, 90.0, and 0.0% of cerambycid, elaterid, mordellid, and scolytid beetle species, respectively, were endemic to the Ogasawara Islands. More cerambycid, elaterid, and mordellid individuals were captured in June–July than in October–November; the number of scolytid individuals did not differ between seasons. More cerambycid, elaterid, and scolytid individuals were captured in artificial gaps than on the closed-canopy forest floor. Although fewer mordellid individuals were captured in gaps, more endemic mordellids were captured in gaps. More cerambycid and scolytid species were captured in artificial gaps than in closed-canopy areas. The positive responses of beetles to artificial gaps suggest that the removal of B. javanica increases beetle diversity and the abundance of endemic beetles.

Some bees and wasps that host mites have peculiar pocket-like structures called acarinaria. These have long been considered as morphological adaptations to securely transfer beneficial mites into nests, and thus are thought to be the product of a mutualistic relationship. However, there has been little compelling evidence to support this hypothesis. We demonstrated that the parasitic miteEnsliniella parasitica, which uses acarinaria, increases the reproductive success of its host waspAllodynerus delphinalisby protecting it from parasitoid wasps. Every time the parasitoidMelittobia acastaaccessed a prepupal or pupal wasp host cell, adult mites attacked it, continuously clinging to it and possibly piercing the intersegmental membrane of the parasitoid with their chelicerae. Subsequent mortality of the parasitoid depended on the number of attacking mites: an average of six mites led to a 70% chance of mortality, and 10 mites led to a 100% chance of mortality. In this way, parent mites protect the food source (juvenile wasps) for themselves and ultimately for their offspring. We propose that wasps evolved acarinaria to maintain this protective guarding behaviour.

Natural vegetation is often replaced by invasive alien plants on isolated oceanic islands. To determine how invasive alien plants affect insect diversity, we compared flying insects captured using Malaise traps among different vegetation types on a small island (Nishijima; 0.49 km2) in the oceanic Ogasawara (Bonin) Islands in the north-western Pacific. The numbers of individuals and species, and the species composition of pollinators (bees), predators (wasps) and wood borers (cerambycid, mordellid and elaterid beetles) were compared among three vegetation types: Casuarina equisetifolia (an invasive alien tree) forest, natural forest and natural grassland (forest edge), during two seasons (June and October–November 2005). In traps, 80.0, 66.7, 87.5, 85.7 and 100.0% of bee, wasp, cerambycid, mordellid and elaterid beetle species, respectively, were endemic to the Ogasawara Islands. Grassland had the highest wasp and bee species richness, whereas natural forest had the highest species richness of wood-boring beetles. The C. equisetifolia forest had the poorest species richness for most insect groups (except mordellid beetles). More individuals of most insect groups (except bees) were captured in June than in October–November. More individual bees and wasps were captured in grassland than in forests, whereas more individual mordellid and elaterid beetles were captured in forests than in grassland. The number of cerambycid individuals did not differ among vegetation types. Redundancy analysis suggested that most insect species preferred natural forest or grassland to alien forest. Therefore, further invasion of natural grassland and forest by the alien tree C. equisetifolia may negatively affect the endemic insect fauna of Nishijima.

Phoretic deutonymphs of Sennertia alfkeni and S. japonica, both associated with the Japanese large carpenter bee, Xylocopa appendiculata, were distinguished by Fain (1974) by body size and the presence or absence of a spine proximal to the pretarsal claw. Despite these morphological differences, rearing of iso‐female lines yielded both morphological forms, thus revealing that both were the same species but functionally different during phoresy. Adults also expressed variation in the form of the dorsal setae, ranging from narrow to broad. We hypothesized that deutonymphal morphology was controlled environmentally, but that the adult setal morphology was at least partially controlled genetically. Both types of deutonymphs disembarked from a female bee during the host tunnelling through provisioning of nests in spring, but there seemed to be no behavioural difference between the two morphs at the time of disembarkation.

Flower visitors recently decreased in the Ogasawara Islands which are subtropical Pacific oceanic islands located 1,000 km south from Japan mainland. The aim of this study was to determine the main cause of this pollinator decline. We assumed four hypothesis, (i) honeybee competition hypothesis, (ii) forest decline hypothesis, (iii) agricultural insecticides hypothesis, and (iv) anole predation hypothesis. They were tested by distribution survey in the field, historical survey using literature, and predation experiment using mesh cages. As a result, the factors affecting the distribution among the islands and the timing of observed declines of native pollinators supported the anole predation hypothesis rather than other hypotheses. In addition, result of experimental predation test well explained the composition of flower visitors in the main islands (Chichi-jima and Haha-jima). So, we concluded that one invasive predator (the anole) has changed the pollination network in the Ogasawara Islands. To conserve the native pollination network, eradication of this invasive predator should take priority over the eradication of honeybees.

Sphaerularia vespae sp. nov., an endoparasite of a common Japanese hornet, Vespa simillima is described from Hokkaido, Japan, and its molecular sequence profiles are given. This newly discovered nematode appears to belong to the genus Sphaerularia, judging from its characteristic parasitic form, the uterium, which looks like a sausage with many verrucae on its surface. Sphaerularia vespae sp. nov. is distinguished from S. bombi, the only other nominal species of the genus, by the morphology of the male bursa, female tail, and anterior end of parasitic juveniles. SSU, ITS, and D2D3 (LSU) DNA sequences were determined for S. vespae sp. nov. and compared with those from related nematodes obtained from the GenBank database. The sequences from S. vespae sp. nov. were close to those of S. bombi and several another tylenchid entomoparasitic nematodes. Sphaerularia vespae sp. nov. parasitizes overwintering gynes of the hornet and practically sterilizes them, as S. bombi does for bumblebee gynes.

Bees are important pollinators for many flowering plants. Female bees are thought to be more effective pollinators than male bees because they carry much more pollen than males. Males of some solitary bee species are known to patrol near flowers that females visit. Because patrolling males visit flowers to mate or defend their territories, they may function as pollinators. However, the significance of patrolling males to pollination has not been studied. We studied males of a solitary bee, Heriades fulvohispidus (Megachilidae), patrolling near flowers and visiting flowers that attracted nectar-feeding insects, including conspecifics, on the Ogasawara (Bonin) Islands. To test the hypothesis that patrolling male bees may function as pollen vectors, we compared the frequency of visits by H. fulvohispidus to flowers of an endemic plant, Schima mertensiana (Theaceae); comparisons were made among flowers with a dead H. fulvohispidus, a dead beetle, a piece of plastic, and nothing (control flowers). Patrolling H. fulvohispidus more frequently visited flowers with a dead conspecific, a dead beetle, or a piece of plastic than the control flowers. Our experiment demonstrates that nectar-feeding insects (including conspecifics and other insects) enhance the flower-visiting frequency of patrolling H. fulvohispidus males on S. mertensiana flowers. Furthermore, we observed S. mertensiana pollen on patrolling males as well as females, suggesting that male bees may also function as pollen vectors.

Summary The structure and feeding group composition of collembolan communities were studied in secondary deciduous forests of different ages to investigate the collembolan community response to environmental changes associated with forest cycles. The study was carried out at eight sites forming a chronosequence (1, 4, 12, 24, 51, 54, 71 and 128 years after clear cutting) of deciduous forest stands in northern Ibaraki (Japan). Total collembolan density and species richness was low at the 1-year-old site, and there was little difference in density among sites over 4 years of age. The density of sucking feeders was especially low at the 1-year-old site. Species richness of trees of a diameter at breast height (DBH)

We examined structures of acarinaria and phoretic mite faunas of the large carpenter bees Xylocopa amamensis, X. flavifrons, X. albinotum, and X. ogasawarensis from Japan, and compared them with those of X. tranquebarorum and X. ruficeps from Taiwan. While the first three Japanese Xylocopa bees had acarinaria both on the mesosoma and on the first metasomal tergum like the common Japanese large carpenter bee, X. appendiculata circumvolans, X. ogasawarensis did not have distinctive mesosomal acarinaria. Xylocopa tranquebarorum, which nests in bamboo, did not have either kind of acarinarium. Of the species examined, only X. ruficeps had a distinctive metasomal acarinarium, which was a deep, round cavity that opened on the first metasomal tergum. All mites except for Dinogamasus were collected from host's mesosoma, wing base furrows, mesosomal acarinaria and the metasomal acarinarium. We collected mites of two Sennertia spp. (alfkeni, japonica) and Horstia helenae from the Japanese bees. The Taiwanese bees also carried Sennertia and Horstia mites but probably of different species. Only X. ruficeps carried mesostigmatid mites (Dinogamasus sp.) in the metasomal acarinarium. We suggest that Sennertia deutonymphs are well adapted to be phoretic on the large carpenter bees with specialized body structures such as attachment organs and hook-like pretarsal claws as seen in other astigmatids phoretic on bees. In contrast, putatively beneficial mites, such as those of the genus Dinogamasus, have possibly been specialized to settle in the distinctive acarinaria in the course of mutualistic evolution with the host.

The life cycle of Kurosaia jiju, a mite phoretic on the mason wasp Anterhynchium flavomarginatum micado, is described based on the results of field observations and artificial rearing of the host. One to two deutonymphs of the mite, on average, disembarked from a female wasp and migrated into a host cell while the host was laying an egg or provisioning the cell with prey. The deutonymphs quickly molted to tritonymphs and then to female adults, which copulated with their single sons (small-type males) that they produced ovoviviparously and laid a mean of ≈300 eggs for about 1 wk. Tritonymphs and adults fed on hemolymph of prey provisioned by the wasp and facultatively on host larvae, whereas larvae and protonymphs scavenged various organic debris, including prey feces. Eggs of the mite hatched when nonoverwintering prepupal host turned into pupae, and then larval mites molted to protonymphs on the host pupae. Protonymphs became deutonymphs 12–24 h before host eclosion, and they attached to specifi...

The adult eumenid wasp, Allodynerus delphinalis delphinalis (Giraud), had obvious acarinaria (mite chambers) on the propodeum, the second metasomal tergite, and the scutellum, harboring deutonymphs of the mite Ensliniella parasitica Vitzthum. The scutellar acarinaria, first described here in detail, were a pair of deeply invaginated chambers situated on both sides of the scutellum, connected to the outside via a very small orifice. The metasomal acarinarium, located on the base of the second tergite, had clear sexual dimorphism. In the female, it was an almost completely closed, capacious chamber, while in the male, it was a wide furrow overhung by a lamella that extended backward from the margin of the second tergite. Newly emerged female and male wasps had a total of 148 and 44 deutonymphs on average, respectively, in the acarinaria. In the female, the metasomal acarinaria supported the largest mite population, while in the male, the scutellar acarinaria were the principal mite chambers.

This study aims to infer the proportion of queens and workers of the hornet Vespa analis parasitized by the strepsipterous parasite Xenos moutoni in overwintered females from morphological data collected for three years. It is known that both worker and queen hornets parasitized by strepsipterous insects overwinter. The parasitized queens cannot reproduce in the next season and thus the level of parasitism potentially affects the number of colonies to be established in the population. Thus, estimation of the ratio of parasitized queens to the total of parasitized females would be useful for understanding the population dynamics of the hornet. K-means cluster analysis demonstrated that 50 to 85% of individuals were workers in the total of parasitized females during the period. From 8 to 15% of total queens were thought to be sterilized by X. moutoni, a level that would not be expected to have a serious effect on the population dynamics of V. analis. Forced hibernation of workers might be considered to be a result of manipulation of the diapause system of the host by the parasite to increase its reproductive success.

The oviposition season and developmental time of Sipalinus gigas were investigated by periodic setting and collection of cut pine bolts at different times in a Pinus densiflora stand in central Kyushu. The number of S. gigas colonized in the bolts was estimated as the sum of the number of holes that were 3 mm or larger in dia. without scolytids and the ones less than 3 mm dia. with S. gigas larva. The oviposition season of S. gigas in the study stand was normally late April through mid-August with a peak in early summer. The eggs laid early in the oviposition season could grow to adults emerging in the autumn of the same year, although many overwintered as larvae and some of the survivors emerged as adults by November of the following year.

1 In the spring, females of the leaf beetle Gonioctena sibirica deposited larvae on the ventral surface of growing young leaves situated on the apical position of shoots of the willow Salix bakko. 2 The parent females remained with the larvae usually on the underside of the basal part of leaves, facing toward the base of shoots. When other arthropods approached, the females temporarily moved towards these intruders, showing aggressive behaviour such as swinging the body or stamping the legs. Many females remained with their larvae until the larvae grew into the final (fourth) instar. No female produced an additional brood in the field. 3 Broods from which parent females were experimentally removed suffered higher mortality than those in which females were left intact. Arthropods such as spiders and ants were observed preying on the larvae. In contrast, the survivorship of broods from which females were removed and intruders were excluded with a sticky substance applied to the base of twigs was not different from that of control broods. These results demonstrate that the main mortality factor of offspring is pedestrian arthropod predators and females physically repel the predators. 4 Potentially alternative reproductive strategies, such as producing a large number of offspring by iteroparity and/or larger brood(s) with less or no care, seem to be inhibited in G.sibirica by larval dependence on growing young leaves which are temporally limited and by ovoviviparity which may have limited brood size.

The community structures of Mesostigmata, Prostigmata, and Oribatida in the soil of broad-leaved regeneration forests and conifer plantations of various ages were assessed alongside soil and plant environmental variables using three response metrics (density, species richness, and species–abundance distribution). The density and species richness of mites recovered swiftly after clear-cutting or replanting. Oribatid mites dominated the soil mite communities in terms of densities and species richness for both forest types. Soil mite communities in broad-leaved forests was related to forest age, the crown tree communities index, and forest-floor litter weight. In contrast, soil mite communities in the conifer plantation sites were related to various indices of understory plants. The development of the understory plants was synchronized with the silvicultural schedules, including a closed canopy and thinning. Such a conifer plantation management may affect indirectly the community of mites.

Two Hibiscus (Malvaceae) species coexist on the oceanic Bonin (Ogasawara) Islands: Hibiscus glaber (an endemic species) and H. tiliaceus (the ancestral non-endemic species). Hibiscus tiliaceus produces extrafloral nectar from the sepals, while H. glaber does not. To clarify the effects of extrafloral nectar loss on Hibiscus-insect relationships, we examined herbivory and insect communities on flower buds of H. glaber and H. tiliaceus. Larvae of the endemic moth Rehimena variegata (Lepidoptera: Pyralidae) attacked 20% of the flower buds on H. glaber, while less than 0.2% of buds on H. tiliaceus were attacked. Introduced species of ants frequently visited the flower buds of H. tiliaceus to collect extrafloral nectar from the sepal, while they rarely visited those of H. glaber. Therefore, extrafloral nectar on H. tiliaceus sepals may function as a facultative defense against flower bud herbivory. The loss of extrafloral nectaries of H. glaber sepals may be related to the original paucity of native herbivores and ants on the Bonin Islands.

Collembolan communities in conifer plantations (Japanese cedar, Cryptomeria japonica) and secondary deciduous broad-leaved forests of varying ages were investigated to determine the extent to which forest conversion (broad-leaved to coniferous) affects the species richness and assemblage composition of Collembola in central Japan. Density and total species richness of Collembola not differed between the broad-leaved and cedar forests except immediately after clear-cutting. The amount of forest-floor organic matter was larger in cedar forests and positively correlated with the species richness of detritus feeders. Species richness of fungal feeders and sucking feeders positively correlated with the species richness of forest-floor plants. There was difference in collembolan species composition between the forest types. The age of the forests seemed to have only small importance for the collembolan community, except during the first four years after clear-cutting. The conversion to artificial cedar stands has not reduced the abundance or species richness of collembolan communities, but has affected community composition. Differences in species composition may be related to the ground floras. As comunidades de colêmbolos nas plantações da conífera Cryptomeria japonica (cedro japonês) e florestas decíduas secundárias de várias idades foram investigadas para determinar até que ponto a conversão da floresta decídua em conífera afeta a riqueza das espécies e a composição das comunidades de colêmbolos no Japão central. A densidade e a riqueza total de espécies de Collembola não foram diferentes entre as florestas decíduas e de cedro, exceto imediatamente depois do corte raso. A quantidade de matéria orgânica acumulada no solo foi maior sob cedro e positivamente correlacionada com a riqueza de espécies de detritívoros. A riqueza de espécies de fungívoros e sugadores foi positivamente correlacionada à riqueza de espécies de plantas do estrato herbáceo da floresta. Houve diferença na composição das espécies de colêmbolos entre os tipos de floresta. A idade das florestas parece ter pouca importância para a comunidade de colêmbolos, exceto nos primeiros quatro anos após o corte raso. Concluiu-se que a conversão da floresta decídua em plantações de cedro japonês não causou diminuição na abundância e na riqueza das espécies das comunidades de colêmbolos, mas afetou a composição dessas comunidades. As diferenças na composição das espécies podem ser relacionadas ao desenvolvimento de plantas do estrato herbáceo da floresta.

Intraspecific nest usurpation by foundresses was studied in 2 haplometrotic (solitary founding) species of different subgenera,Polistes (P.) riparius andP. (Polistella) snelleni, in areas where they cohabited. The overall probability for a nest to be usurped by a foreign foundress during the season was about twice as large inP. snelleni as inP. riparius. In both, however, probability of usurpation was largest on late pre-emergence nests, or in late June and early July. InP. riparius, all the usurpers of known origins were those foundresses that had lost their pre-emergence nests to destruction probably by some vertebrates; inP. snelleni, some usurpers had the same history as above, while the others had lost many of all larvae to predation by unknown agents before worker emergence. Usurpers of both species destroyed eggs and younger larvae to much greater extents than older larvae or pupae, and they produced fewer numbers of reproductives in comparison with non-usurping foundresses. We concluded that usurpation behavior has been maintained despite its relatively low productivity because renesting would lead to even lower or no reproductive production.

For protection from HIV-1 infection, a vaccine should elicit both humoral and cell-mediated immune responses. A novel vaccine regimen and adjuvant that induce high levels of HIV-1 Env-specific T cell and antibody (Ab) responses was developed in this study. The prime-boost regimen that used combinations of replication-competent vaccinia LC16m8Δ (m8Δ) and Sendai virus (SeV) vectors expressing HIV-1 Env efficiently produced both Env-specific CD8(+) T cells and anti-Env antibodies, including neutralizing antibodies (nAbs). These results sharply contrast with vaccine regimens that prime with an Env expressing plasmid and boost with the m8Δ or SeV vector that mainly elicited cellular immunities. Moreover, co-priming with combinations of m8Δs expressing Env or a membrane-bound human CD40 ligand mutant (CD40Lm) enhanced Env-specific CD8(+) T cell production, but not anti-Env antibody production. In contrast, priming with an m8Δ that coexpresses CD40Lm and Env elicited more anti-Env Abs with higher avidity, but did not promote T cell responses. These results suggest that the m8Δ prime/SeV boost regimen in conjunction with CD40Lm expression could be used as an immunization platform for driving both potent cellular and humoral immunities against pathogens such as HIV-1.

Dispersion capabilities of new queens were studied in the two haplometrotic paper waspsPolistes riparius andP. 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.

1. Losses in workers and reproductives due to the ichneumonid parasitoidLatibulus sp. were determined in a haplometrotic, temperate paper wasp,Polistes riparius, during a 5-year study. 2. Fifty-four to 79% of pre-emergence nests were parasitized on worker brood, resulting in a worker loss of 25–31% on average. Worker brood reared in outer cells were much more often parasitized than those in central ones, possibly because outer cells are more accessible to the parasitoid. Infestation of worker brood was not random but aggregated among nests. 3. Seventy-eight to 100% of nests were parasitized on reproductive brood, and lost 10–34% of reproductives. 4. The number of emerged workers positively correlated with that of reproductives produced and that of cells made during the season. This suggests that worker loss reduces reproductive output of colonies. Hence, the parasitoid can reduce colonial reproductive output not only by killing reproductive brood but by reducing worker force.

1985年秋,北海道農業試験場(札幌市)のテンサイ根腐病発生圃場で,病原菌Rhizoctonia solani Kuhn AG-2-2の菌核と菌糸を摂食し,崩壊させる双翅目昆虫ジャガイモクロバネキノコバエPnyxia scabiei(Hopkins)を見いだした。幼虫は菌核にい集し,摂食も旺盛であった。すなわち室内実験では,菌核15個と幼虫30頭を直径6cmシャーレに入れると,菌核は24時間以内にほとんど食い尽くされ,消失した。摂食温度は10～30C,最適は25Cであった。R. solani菌糸融合群間では,菌核に対する摂食はAG-2-2, AG-3およびAG-5で活発で, AG-1, AG-2-1およびAG-4は劣った。圃場では,本種昆虫はテンサイ根腐病の発病・蔓延に伴って急増した。激発株では1株当たりの幼虫数が5,000頭を超える場合もあった。幼虫の多くは腐敗部根面および付着土壌に集中して分布した。AG-2-2菌核を10または250μmフィルター付きの容器内に入れ,激発株周囲に3週間埋めると,菌核の崩壊は250μm区だけに起こった。また菌核15個,幼虫30頭を無殺菌土壌を詰めたテンサイ育苗用紙筒に埋めると, 9日後菌核はまったく回収されなかった。以上の結果から,本種昆虫は根腐病発生後根圏のR. solani AG-2-2菌核の密度を低下させる一要因となる可能性が示唆される。