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Anopheles stephensi is an Asian and Middle Eastern malaria vector, and it has recently spread to the African continent. It is needed to measure how the malaria parasite infection in A. stephensi is influenced by environmental factors to predict its expansion in a new environment. Effects of temperature and food conditions during larval periods on larval mortality, larval period, female wing size, egg production, egg size, adult longevity, and malaria infection rate were studied using a laboratory strain. Larval survival and female wing size were generally reduced when reared at higher temperatures and with a low food supply during the larval period. Egg production was not significantly affected by temperature during the larval period. Egg size was generally smaller in females reared at higher temperatures during the larval period. The infection rate of mosquitoes that fed on blood from malaria-infected mice was not affected by rearing temperature or food conditions during the larval period. Higher temperatures may reduce infection. A. stephensi; however, larger individuals can still be infective. We suggest that routinely recording the body size of adults in field surveys is effective in finding productive larval breeding sites and in predicting malaria risk.

Myco-talpology is the science of mushrooms and talpid moles based on our discovery in 1976 that underground mole nests can be located by the aboveground fruiting of the agaricsHebeloma danicumorHebeloma sagarae, a Japanese sibling species of EuropeanHebeloma radicosum. Hyphae of these mushrooms specifically colonise mole latrines near nests, forming ectomycorrhizas with the roots of their host trees. By this process, the hyphae and roots absorb, transform, and translocate the nutrients from mole excretions, cleaning the mole’s habitat. The mushrooms fruit on the ground with thick root-like tissue stretching up from the ectomycorrhizas. The presence of the fruit bodies serves as the only indicator for underground mole nests, enabling us to provide novel insights into mole ecology. We excavated 74H. sagaraeorH. danicumsites in Japan and 13H. radicosumsites in Europe and identified the nesting species. These investigations provided new perspectives on latrine making, nest structure, breeding and nestlings, the neighbouring presence of different Talpini species, and long-term nesting at the same site with inhabitant changes. Moreover, they suggested that a tripartite habitat-cleaning symbiosis among moles, mushrooms, and mushroom-host trees in the latrine must have existed for a long time in Japanese and European forests. While moles are traditionally considered inhabitants of open areas, their special relationship with mushrooms and trees suggests they may originally be forest inhabitants.

Recurring seasonal changes can lead to the evolution of phenological cues. For example, many arthropods undergo photoperiodic diapause, a programmed developmental arrest induced by short autumnal day length. The selective mechanisms that determine the timing of autumnal diapause initiation have not been empirically identified. We quantified latitudinal clines in genetically determined diapause timing of an invasive mosquito, Aedes albopictus, on two continents. We show that variation in diapause timing within and between continents is explained by a novel application of a growing degree day (GDD) model that delineates a location‐specific deadline after which it is not possible to complete an additional full life cycle. GDD models are widely used to predict spring phenology by modelling growth and development as physiological responses to ambient temperatures. Our results show that the energy accumulation dynamics represented by GDD models have also led to the evolution of an anticipatory life‐history cue in autumn., We show that variation in the timing of a mosquito's autumnal diapause timing within and between continents is explained by a growing degree day (GDD) model that delineates a location‐specific deadline after which it is not possible to complete an additional full life cycle. GDD models are widely used to predict spring phenology by modeling growth and development as physiological responses to ambient temperatures. Our results show that the energy accumulation dynamics represented by GDD models have also led to the evolution of an anticipatory life‐history cue in autumn.

To understand how ectomycorrhizal (ECM), wood-decomposing (WDC) and litter-decomposing (LDC) fungi differ in abundance and fruiting season, fruiting-body production was monitored by counting their number and/or measuring their biomass in deciduous broad-leaved and coniferous forests in Ishikawa (central Japan) and Hokkaido (northern Japan). ECM fungi were dominant in forests of both types in Ishikawa and a Larix kaempheri forest in Tomakomai (Hokkaido), whereas WDC fungi were dominant in a deciduous broad-leaved forest in Sapporo (Hokkaido). ECM and WDC fungi usually showed two abundance peaks in Kanazawa (Ishikawa), mid-summer and autumn for ECM fungi and spring or summer and autumn for WDC fungi, whereas LDC fungi usually showed one peak in autumn. In Tomakomai, the abundance peak appeared later in ECM fungi but earlier in LDC and WDC fungi in comparison with Kanazawa. The mode of resource acquisition is assumed as one of factors that affect the seasonal timing of fruiting-body production. On the other hand, highly positive correlations were often observed between precipitation in Jun or Aug and the fruiting-body production in summer and/or autumn in the survey in Kanazawa, suggesting that precipitation could affect the fruiting-body production a few months later.

Aedes (Stegomyia) albopictus and Aedes (Stegomyia) flavopictus are related species that have overlapping distributions from southern to central Japan. To understand how they interact, we studied reproductive interference between them, particularly focusing on the body size difference between the mating pair. Here, we examined the effects of conspecific, heterospecific and double mating (i.e. heterospecific mating followed by conspecific mating) on copulation duration, egg production and hatchability of eggs using mosquitoes that varied in body size. Females mated only with heterospecific males produced few viable eggs, indicating that post-mating isolation is almost complete. When mated with heterospecific males before conspecific mating, the production of viable eggs was lower than when mated only with conspecific males, revealing the occurrence of reproductive interference. The degree of reproductive interference was larger in Ae. flavopictus than in Ae. albopictus when the female size was small but did not differ between them when the female size was large. Aedes albopictus females appear to be able to distinguish Ae. flavopictus males from conspecific males and larger females are more successful in the rejection of heterospecific males. On the other hand, Ae. flavopictus were not able to discriminate between conspecific and heterospecific males.

The Asian mosquitoes, Aedes albopictus (Skuse) and Aedes japonicus japonicus (Theobald), have invaded North America, Europe, and other regions since the late 20th century. In invasive ranges, Ae. albopictus has well been recognized as urban, domestic species, whereas views about the macrohabitats of Ae. j. japonicus are inconsistent. Previous reports in Japan suggest the disappearance of Ae. j. japonicus from metropolises. However, container-mosquito larvae have not been inspected simultaneously for various macro and microhabitats in metropolises in Japan. The current study in Fukuoka City, a metropolis in southwest Japan, confirmed the absence of Ae. j. japonicus irrespective of macrohabitats (temples with graveyards, shrines, public graveyards, cultivated bamboo groves, and urban forests, all within the area densely inhabited by humans) and microhabitats (container types). In contrast, Ae. albopictus was dominant throughout the macro and microhabitats except forest tree holes rich with competitive species. Past records indicate the disappearance of Ae. j. japonicus from metropolitan Fukuoka within the last 70 yr. Based on careful examination of available evidence, we concluded that 1) both species benefit from human-made environments with artificial containers free from competitors, 2) Ae. j. japonicus disappeared due to hot, dry summer conditions facilitated by urban heat-island effects and a decrease in favored mammal hosts, and 3) Ae. albopictus has proliferated with higher tolerance to hot, dry climate and a wider blood-feeding host-range including humans. This difference is important for efficient control of each species as well as predicting and preventing the expansion into new distribution ranges.

The summer of 2018 was very hot and dry with little rain nationwide in Japan. Particularly in July, temperature was 3°C higher in comparison with the normal year. We collected adults, pupae, third or fourth instar larvae of Aedes albopictus (Skuse) in Sendai city, Niigata city, and Kanazawa city in late July and early August 2018. Wild-collected adults were examined for reproductive capacity. On the other hand, wild-collected larvae and pupae were raised to adults in the laboratory and then examined for reproductive capacity. They did not lay eggs after single blood feeding. When they were supplied with bloodmeals twice or three times, they laid a small number of eggs, but these eggs did not hatch. When these adult individuals were maintained at 25°C for 3 wk and then fed with blood, they laid healthy eggs which developed to embryos. It is thought that extreme heat and/or extreme low humidity due to low precipitation reduced female reproductive capacity even if they could take bloodmeals.

(1) Dengue is the most spread mosquito-borne viral disease in the world, and vector control is the only available means to suppress its prevalence, since no effective treatment or vaccine has been developed. A biological control program using copepods that feed on mosquito larvae has been practiced in Vietnam and some other countries, but the application of copepods was not always successful. (2) To understand why the utility of copepods varies, we evaluated the predation efficiency of a copepod species (Mesocyclops aspericornis) on a vector species (Aedes aegypti) by laboratory experiments under different temperatures, nutrition and prey-density conditions. (3) We found that copepod predation reduced intraspecific competition among Aedes larvae and then shortened the survivor&rsquo, s aquatic life and increased their pupal weight. In addition, the predatory efficiency of copepods was reduced at high temperatures. Furthermore, performance of copepod offspring fell when the density of mosquito larvae was high, probably because mosquito larvae had adverse effects on copepod growth through competition for food resources. (4) These results suggest that the increase in mosquitoes will not be suppressed solely by the application of copepods if the density of mosquito larvae is high or ambient temperature is high. We need to consider additional control methods in order to maintain the efficiency of copepods to suppress mosquito increase.

金沢大学理工研究域自然システム, Muscina angustifrons (Diptera: Muscidae) is a mycophagous species that exploits a variety of fungi, including ectomycorrhizal fungi. Larvae of this species have been shown to feed on sporocarps (including spores), and full-grown larvae leave sporocarps and pupate 0-6 cm below the soil surface. In this study, we examined whether M. angustifrons larvae are capable of transporting ectomycorrhizal fungal spores and enhancing ectomycorrhiza growth on host-plant roots. Full-grown larvae were found to move horizontally 10-20 cm from their feeding sites and burrow underground. These wandering larvae retained ectomycorrhizal fungal spores in their intestines, which were excreted following relocation to underground pupation sites. Excreted spores retained germination and infection capacities to form ectomycorrhiza on host-plant roots. In the infection experiments, ectomycorrhizal fungal spores applied in the vicinity of underground host-plant roots were more effective in forming ectomycorrhiza than those applied to the ground surface, suggesting that belowground transportation of spores by M. angustifrons larvae could enhance ectomycorrhizal formation. These results suggested that M. angustifrons larvae act as a short-distance spore transporter of ectomycorrhizal fungi. © 2018., Embargo Period 12 months

The population sizes of Anopheles gambiae Giles (Diptera: Culicidae) and Anopheles arabiensis Patton (Diptera: Culicidae) increase dramatically with the onset of the rainy season in sub-Saharan Africa, but the ecological mechanisms underlying the increases are not well understood. As a first step toward to understand, we investigated the proliferation of algae, the major food of mosquito larvae, in artificial fresh water bodies exposed to sunlight for a short period, and old water bodies exposed to sunlight for a long period, and the effects thereof on the development of these anopheline larvae. We found that an epizoic green algal species of the genus Rhopalosolen (Chlorophyta: Chlorophyceae) proliferated immediately after water freshly taken from a spring was placed in sunlight. This alga proliferated only briefly (for ~10 d) even if the water was repeatedly exposed to sunlight. However, various algal species were observed in water that remained under sunlight for 40 d or longer (i.e., in old water bodies). The growth performance of larvae was higher in sunlight-exposed (alga-rich) water than in shade-stored (alga-poor) water. Stable isotope analysis suggested that these two anopheline species fed on Rhopalosolen algae in fresh water bodies but hardly at all on other algae occurring in the old water bodies. We concluded that freshly formed ground water pools facilitate high production of anopheline species because of the proliferation of Rhopalosolen algae therein, and the increase in the number of such pools in the rainy season, followed by rapid increases in A. gambiae and A. arabiensis numbers.

金沢大学理工研究域自然システム, We compared climatic distribution ranges between Aedes albopictus (Skuse) (Diptera: Culicidae) and the five wild (nondomesticated) species of Albopictus Subgroup of Scutellaris Group of Aedes (Stegomyia) in southern Asia. Distribution sites of the wild species concentrate in seasonal forest and savannah climate zones in India, Indochina, and southern China. The distribution of Ae. albopictus is broader than the wild species under 1) tropical rain-forest climate, 2) steppe and temperate savannah climate, and 3) continental climate with large seasonal temperature variation (hot summer and cold winter) at temperate lowlands (northernmost sites 40°N in Ae. albopictus vs 32°N in the wild species). However, the distribution of Ae. albopictus is more limited at tropical and subtropical highlands where the climate is cool but less continental (small seasonal variation, mild summer, and winter). We discuss a possibility that the broader climate ranges of Ae. albopictus are ecological or eco-evolutionary consequences of adaptation to human habitats. We also propose a general scenario for the origin, dispersal, and adaptation of Ae. albopictus in Asia as a hypothesis for future research. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com., Embargo Period 12 months

Although most fungal spores are transported by wind, some remain on lamellae even after fungal fruiting bodies start to decay. This raises the question: are these remaining spores useless or instead transported by other means? In this study, we accordingly investigated whether adult dipteran insects transport fungal spores. Our examination revealed that fungal spores were present in intestines of most drosophilid adults but almost completely absent from those of other dipteran adults. At least some spores excreted by Drosophila angularis and D. brachynephros retained the capacity to germinate. Structural damage to spores that passed through the digestive tract of these two drosophilid species varied among fungal species, with a greater number of colorless spores generally damaged than colored ones. These results suggest that adult drosophilid flies, but not other dipterans, can transport fungal spores. © 2017, The Ecological Society of Japan., Embargo Period 12 months

金沢大学理工研究域自然システム学系, Japanese encephalitis virus (JEV) is the most frequent cause of mosquito-borne encephalitis in Asian countries. Several culicine species are potential vectors. The primary JEV vectors feed mainly on cows (a dead-end host for JEV), pigs (an amplifying host), and, occasionally, humans (a dead-end host). It is essential to determine blood-feeding patterns to understand the transmission cycle of the disease. Here we review blood-feeding characteristics of the primary JEV vectors Culex tritaeniorhynchus, Culex vishnui, and Culex gelidus based on experimental works and field surveys conducted in Asian countries. Several studies showed that these JEV vectors have an innate preference for cows; however, the former two species often showed higher rates of blood-feeding on pigs than on cows, probably because pigs are more abundant than cows. On the other hand, the latter species Cx. gelidus fed mostly on cows. Thus, the first two species showed higher plasticity to compromise host availability than the last. By reviewing the available articles and based on our relevant studies, it may be deduced that JEV transmission cannot be reduced by zooprophylaxis. We emphasize the need of keeping cows away from the human residences to dampen the human risk of JEV. These primary JEV vector species exhibit pre-biting resting. The adaptive significance of this behavior remains to be unexplored, but it may have a function to avoid defensive attack of host animals. Application of recent quantitative analysis of gene expression in this phase may enable us to come up with novel vector control strategies. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com., Embargo Period 12 months

Despite its potential effectiveness for outcrossing, few examples of pollination via mushroom mimicry have been reported. This may be because the conditions under which the strategy can evolve are limited and/or because demonstrating it is challenging. Arisaema is a plant genus that has been suggested to adopt mushroom mimicry for pollination, although no compelling evidence for this has yet been demonstrated. Here, we report that Arisaema sikokianum utilizes mostly a single genus of obligate mycophagous flies (Mycodrosophila) as pollinators, and that the insect community dominated by Mycodrosophila is strikingly similar to those found on some species of wood-decaying fungi. Comparative chemical analyses of Arisaema spp. and various mushrooms further revealed that only A. sikokianum emits a set of volatile compounds shared with some mushroom species utilized by Mycodrosophila. Meanwhile, other closely related and often sympatric Arisaema species do not possess such typical traits of mushroom mimicry or attract Mycodrosophila, thereby likely achieving substantial reproductive isolation from A. sikokianum. Our finding indicates that mushroom mimicry is an exceptional and derived state in the genus Arisaema, thus providing an unprecedented opportunity to study the mechanisms underlying the coordinated acquisition of mimicry traits that occurred during a recent speciation event.

The impact of climate change on the distribution of Aedes albopictus (Skuse) was analyzed in northern Japan, where chronological distribution records are incomplete. We analyzed local climate data using linear regression of the thermal suitability index (TSI) for the mosquito and mean annual temperature as functions of time. In northern Japan, thermal conditions since the early 20th century have become increasingly suitable for Ae. albopictus, more as a result of decreasing coldness in the overwintering season than increasing warmth in the reproductive season. Based on recent discovery records of Ae. albopictus in the northern border range, we determined thermal criteria for estimating when its persistent establishment became thermally possible. Retrospective analyses indicated that those criteria were reached in most coastal lowlands of northern Honshu before the accelerated temperature increase after the mid-1980s and the first records of this species after 1990; at some sites, temperature criteria were reached during or before the early 20th century. Expansion of the thermally suitable range after 1990 was supported only for inland areas and the northernmost Pacific coast. The estimated expansion rate was ≈26 km per decade. Our analyses also demonstrated the importance of local climate heterogeneity (apart from north-south or altitudinal temperature gradients) in determining the expansion pattern. © 2014 Entomological Society of America.

Megaselia donaldsonae Disney sp. nov., M. flava (Fallen), M. gotoi Disney, M. kanekoi Disney, M. margaretae Disney sp. nov., M. nakayamai Disney sp. nov., M. salteri Disney sp. nov. and M. stepheni Disney sp. nov. were reared from sporophores of fungi.

The body size of mosquitoes can influence a number of bionomic factors, such as their blood-feeding ability, host attack rate, and fecundity. All of these traits are important determinants of their potential to transmit diseases. Among abiotic and biotic factors, high temperature and low nutrition in the developing stages of mosquitoes generally result in small adults. We studied the relationship between body size and multiple feeding in a gonotrophic cycle and some fecundity attributes by using three strains of two competent vector species, Aedes aegypti (L.) and Aedes albopictus (Skuse). We raised small and large mosquitoes under low and high food conditions in the laboratory to measure parameters of fecundity and blood-feeding behavior. Fecundity was positively correlated with body size in both species, whereas the number of bloodmeals, the frequency of host-seeking behavior, and egg retention were negatively correlated with body size in the Ae. albopictus Nagasaki strain. We found that multiple feeding and host-seeking behavior were negatively correlated with body size, i.e., small mosquitoes tended to have more contact with hosts. We found that two mechanisms that inhibit engorged mosquitoes from seeking out hosts, distension-induced and oocyte-induced inhibition, were not strong enough to limit host-seeking behavior, and multiple feeding increased fecundity. Size-dependent multiple feeding and host-seeking behavior affect contact frequency with hosts and should be considered when predicting how changes in mosquito body size affect disease transmission.

We asked whether climate change might affect the geographic distributions of Aedes aegypti (L.) and Aedes albopictus (Skuse) (Diptera: Culicidae). We tested the effects of temperature, diet and the presence of congeneric species on the performance of immature stages of these two aedine species in the laboratory. Mosquitoes in three different species-density combinations were reared at four constant temperatures (20 °C, 25 °C, 30 °C, 35 °C) on low- or high-level diets. Of the four temperatures tested, mortality increased only at 35 °C in both species. Mortality was higher on the high-level diet than on the low-level diet at 35 °C, but not at other temperatures. The presence of congeneric species had a significant positive effect on mortality in Ae. albopictus, but not in Ae. aegypti. Both species developed more quickly at higher temperatures within the range of 20-30 °C; development was not enhanced at 35 °C. Population growth of Ae. albopictus was more stable, regardless of diet and temperature; that of Ae. aegypti varied more according to these two factors. These species-specific attributes may help to explain the latitudinal distribution of the mosquitoes and degree of species dominance where they are sympatric. © 2011 The Authors. Medical and Veterinary Entomology © 2011 The Royal Entomological Society.

Multiple blood feeding (MBF) in a gonotrophic cycle in vector mosquitoes influences pathogen transmission by increasing host-vector contact. Multiple blood meals can be caused by malnutrition in the larval stage, a harsh environment in the adult stage, or interrupted feeding due to host defense. We focused on the effect of body size on MBF in two vector mosquitoes, Aedes aegypti (L.) and Aedes albopictus (Skuse), in the laboratory, using small and large adults of both species. Most females (94.3% of Ae. aegypti and 88.2% of Ae. albopictus) oviposited with the first blood meal. There was no relationship between body size and MBF proportion in either species. However, there was a negative relationship between body size and egg retention ratio in Ae. albopictus ovaries and between body size and the ratio of immature follicles in both species. Small Ae. albopictus laid some eggs but retained the rest in their ovaries, as did 5.3% of Ae. aegypti. Large Ae. albopictus developed 68.4–81.7% of follicles, whereas, small ones developed about 50%. Large Ae. aegypti developed 98.0–99.8% of follicles, whereas small females developed only 83.5–88.4%. These results suggest that oviposition was incomplete in small females with low energy reserves, and that females emerging under subpar-diet conditions may perform MBF to improve fecundity. 一回の産卵のために複数回の吸血を行う場合を多回吸血と呼ぶ．多回吸血が起こる原因は，幼虫時代の貧栄養，羽化後の過酷な環境，吸血を中断させられた場合などがある．我々は，幼虫時代の栄養条件を反映した成虫の体サイズが多回吸血に与える影響をネッタイシマカとヒトスジシマカの2種で検討した．その結果，多回吸血と体サイズに関係は認められず，ネッタイシマカは94.3% が，ヒトスジシマカでは 88.2% が1回の吸血で産卵した．一方，ヒトスジシマカでは小さい個体ほど，一部の成熟卵を産卵せずに体内に保持する傾向が見られた．また両種とも，幼虫期に貧栄養下で生育した成虫は，吸血後に成熟しない卵巣小管の割合が高くなる傾向がみられた．これらの結果は，成熟卵を保有している個体であっても，産卵数をより増加させるために多回吸血を行う可能性があることを示している．

The toxic ectomycorhizal fungi Amanita muscaria (Agaricales: Amanitaceae) was first recorded in New Zealand in 1937, and it is now widespread throughout the country. We collected decaying fruiting bodies of the mushroom in 2005 and 2006 and placed them in enclosed emergence traps to determine use by fungivorous insects. This study clarified that the endemic species Mycetophila fagi, M. filicornis (Diptera: Mycetophilidae) and Zedura curtisi (Diptera: Trichoceridae), as well as exotic Drosophila busckii (Diptera: Drosophilidae), utilised the exotic A. muscaria in various vegetation types in the North and South Islands of New Zealand. A significant difference was observed in the number of fungivorous insects found on the mushrooms between North and South Islands; the endemic M. fagi was dominant in South Island, while Psychodidae sp. dominated North Island. A significant difference was observed in the number of fungivorous insects between the exotic and endemic vegetation inhabited by A. muscaria. Furthermore, the biodiversity of fungivorous insects on A. muscaria within endemic Nothofagus vegetation was more than three times greater than that within the exotic Betula , Pinus, Pseudotsuga and tsuga vegetation. These observations suggest that the greater diversity of fungivorous insects on A. muscaria in natural Nothofagus forests may reflect the higher diversity found in natural forests compared with plantation forests.

Anopheles gambiae is the predominant malaria vector species in Ghana, western Africa, with a strong local presence of Anopheles melas Theobald along the southern coast. We studied the biting behavior of these two species of the Anopheles gambiae complex inland and at the coast in Ghana, with special attention to the local peoples' preference for outdoor sleeping. We collected mosquitoes at two sites in 2007, representing the moist semideciduous forest zone and the strand and mangrove zone, and the sampling was repeated in the dry and rainy seasons. Sampled mosquitoes were examined for species, parity and size (wing length), and we identified the hosts of their bloodmeals. We interviewed 288 of the village people to determine where and when they slept outdoors. Our study confirmed that An. gambiae is the only species of the An. gambiae complex in the Ashanti region and revealed that An. melas is highly dominant on the western coast of Ghana. Both species showed high human blood rates in indoor resting mosquito samples. More people sleep outside on the coast than inland. An. melas demonstrated high exophily. An. gambiae bit people more frequently indoors and did so more often during the dry season than in the rainy season. We suggest that the degree of exophily in An. melas may be affected by humidity and the availability of human as well as by the mosquitoes' innate habits.

The fecundity and survival of 6 copepod species were assessed under laboratory conditions in order to choose the best candidates to control the aquatic stages of dengue mosquitoes in the field. Females of all the 6 species (Mesocyclops aspericornis, Mesocyclops pehpeiensis, Mesocyclops woutersi, Mesocyclops thermocyclopoides, Mesocyclops ogunnus, and Megacyclops viridis) mated more than once. Multiple mating resulted in increased egg production. The reproductive ability and longevity varied among the species, and M. aspericornis had the highest values. The lowest values were observed in M. thermocyclopoides. Multiple mating of males of M. aspericornis was also observed. The paternal fecundity decreased with each additional mating. There was no difference in the paternal fecundity between the males that mated at low and high female frequencies. The sperm stored in the M. aspericornis females remained viable for 30 days after storage under moist conditions at 25 degrees C or 15 degrees C. This feature in M. aspericornis represents an additional positive factor indicating that this species is a good biological agent for controlling mosquito larvae, especially in domestic water containers that may dry intermittently., Journal of the American Mosquito Control Association, 24(1), pp.61-69; 2008

A field study was conducted in a village in northern Vietnam to investigate how host distribution influences Japanese encephalitis (JE) vector abundance. Indoor and outdoor collections were conducted from 50 compounds. We collected three JE vector species--Culex tritaeniorhynchus and Culex vishnui that comprised the Culex vishnui group and Culex gelidus. Spatial autocorrelation was not observed in the mosquito assemblies at any scale larger than the house compounds. Multivariate analyses revealed that the Cx. gelidus density correlated positively with both the host proximity to the breeding sites and cattle density; however, the Cx. vishnui subgroup density correlated positively only with cattle density. These results showed that the number of cattle in a compound influenced the JE vector abundance in that compound, and the abundance of Cx. gelidus, not of the Cx. vishnui subgroup, was affected by the host proximity to the breeding sites in the village., American Journal of Tropical Medicine and Hygiene, 78(1), pp.159-168; 2008

Anopheline larvae generally inhabit the near-surface of aquatic habitats, but they dive and remain at the bottom of these habitats for some time. This study examined forced and voluntary diving behavior and submergence tolerance in the three major African malaria vectors, Anopheles gambiae Giles, An. arabiensis Patton, and An. funestus Giles. The former two species occur sympatrically in temporal and shallow water bodies, while the latter occurs in permanent deeper water bodies. Anopheles funestus was the most tolerant of submergence, but the larvae tended to halt their descent before reaching the bottom by attaching onto a wall. The difference in diving behavior between An. funestus and the two species in the An. gambiae complex may be an adaptation to their contrasting breeding sites, because the former species must spend considerable energy to surface in its typical breeding sites. Both An. gambiae and An. arabiensis reached the bottom and crawled along the substrate, but An. gambiae voluntarily crawled more often than An. arabiensis. The possible importance of asymmetric bottom-feeding between these two sympatric species is discussed.

The role of Anopheles funestus group in malaria transmission was investigated in Bagamoyo coastal Tanzania, in the process of characterizing the area as a malaria vaccine testing site. Mosquitoes were sampled inside houses and multiplex PCR was used to identify 649 specimens. The following species were found: A. funestus s.s. (84.3%), A. leesoni (13.6%), A. rivulorum (1.5%) and A. parensis (0.6%). Multiplex PCR of 147 blood-fed specimens showed that over half (57.1%) of the identifiable blood meals were taken from human hosts, and human blood index in A. funestus and A. leesoni was 55% and 82% respectively. Plasmodium falciparum infection rate determined by nested PCR was 11% in A. funestus s.s. Although the abundance was low, 26 specimens of A. leesoni, two of A. rivolurum and one of A. parensis were found positive for P. falciparum. The presence of four A. funestus species in Tanzania emphasizes the relevance to define precisely their spatial and temporal distribution, specific behaviour, ecology and exact role in malaria transmission.

Aedes albopictus (Skuse) has expanded its distribution worldwide during the past decades. Despite attempts to explain and predict its geographic occurrence, analyses of the distribution of Ae. albopictus in the context of broad climatic regions (biomes) has not been performed. We analyzed climate conditions at its distribution sites in the range before the worldwide invasions (from the easternmost Hawaii through westernmost Madagascar) by using thermal and aridity-humidity indices descriptive of major biomes. A significant advantage of this approach is that it uses simple indices that are clearly related to the population dynamics of Ae. albopictus. Although it has been regarded as a forest species preferring humid climate, in areas with significant human habitation, the distribution sites extended from the per-humid, rain-forest zone to the semi-arid, steppe zone. This pattern was common from the tropics through the temperate zone. There was no seasonal discordance between temperature and precipitation; at sites where winter (monthly means 10°C) under the Asian summer monsoon. Absence of the species in northern and eastern coastal Australia and eastern coastal Africa was not attributable solely to climate conditions. However, Asia west of the summer monsoon range was climatically unsuitable due to low precipitation throughout the year or in warm months favorable to reproduction (concentration of precipitation in winter). We hypothesized that Ae. albopictus originated in continental Asia under the monsoon climate with distinct dry seasons and hot, wet summer enabling rapid population growth. Fil: Motoyoshi, Mogi. Saga University. Faculty of Medicine; Japón Fil: Armbruster, Peter. Georgetown University; Estados Unidos Fil: Tuno, Nobuko. Kanazawa University; Japón Fil: Campos, Raul Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina Fil: Eritja, Roger. Consell Comarcal del Baix Llobregat; España

The mushroom genus Amanita has a spectrum of chemical compounds affecting survival and performance of animals. Ibotenic acid is one of such compounds found in some Amanita mushrooms. We studied the effects of ibotenic acid and its derivative, muscimol, on egg-to-pupa survival, pupation time, and pupal size in five Drosophila species (Diptera: Drosophilidae), Drosophila bizonata, Drosophila angularis, Drosophila brachynephros, Drosophila immigrans, and Drosophila melanogaster. The first three species are mycophagous and use a wide range of mushrooms for breeding, whereas D. immigrans and D. melanogaster are frugivorous. We reared fly larvae on artificial medium with 500, 250, 125, and 62.5 microg/ml of ibotenic acid and/or musimol. The three mycophagous species were not susceptible to ibotenic acid, whereas the two frugivorous species were affected. In experiments with D. melanogaster, muscimol was less toxic than ibotenic acid.

The western Kenya highland has been experiencing dramatic landuse changes in the past three decades. Landuse change has been hypothesized to be one of the mechanisms for malaria epidemics in African highlands because it can alter the physical and chemical characteristics of mosquito breeding habitats. One important landuse change in western Kenya highland is deforestation. The current study examined the effects of forestation or deforestation on the survivorship of Anopheles gambiae larvae and colonization of other aquatic insects in larval habitats in Kakamega forest (elevation 1,500-1,700 m above sea level), western Kenya. We found that the survivorship of An. gambiae larvae was reduced from 55 to 57% in habitats fully exposed to sunlight (open habitats) to 1-2% in habitats with full forest canopy coverage (forest habitats) and partial canopy coverage (forest edge habitats) in two out of three trials. The average daily water temperature of the open habitats was approximately 3-3.4 degrees C higher than the forest habitats. Insect species in the orders of Diptera, Coleoptera, and Odonata colonized the larval habitats, but the three habitat types differed greatly in the animal assemblage. Canonical correspondence analysis found that water temperature and amount of leaf litter were the significant variables associated with animal assemblages. Redundancy analysis revealed that openness and the presence of predatory animals were significantly related to An. gambiae survivorship. This result suggests that deforestation facilitates the survival of the immature stage of An. gambiae in the highland.

134.The relative importance of spatial aggregation and resource partitioning on coexistencewas investigated for mycophagous insects in central Japan. The effects of spatialaggregation and resource partitioning were separated by a randomization procedure.From 124 patches of macrosporophores belonging to 37 species, 3275 individualsbelonging to 14 families of Diptera and 11 individuals to Lepidoptera emerged. Sincethe level of identification varied among insect taxa, the analysis was made in threeways; 1) for all taxa to assess the stability of the whole community, 2) for drosophilidspecies to assess their persistence in the community, and 3) for species of Drosophilaand Mycodrosophila to assess their persistence against congeneric and heterogenericspecies. Both spatial aggregation and resource partitioning functioned for the stabilityof whole mycophagous insect community, and spatial aggregation played a moreimportant role than resource partitioning. On the other hand, only spatial aggregationfunctioned for the persistence of drosophilid species in the community. According tothe analysis on species of Drosophila and Mycodrosophila against congeneric andheterogeneric species, the relative importance of resource partitioning was smaller forthe coexistence of within-genus species pairs than for that of between-genus speciespairs. These results suggest that the relative importance of these two mechanismsdepends on the phylogenetic and guild diversity of community.K. H. Takahashi and T. Kagaya, Laboratory of Forest Zoology, Dept of Forest Science,Graduate School of Agricultural and Life Sciences, The Univ. of Tokyo, 1-1-1, Yayoi,Bunkyo-ku, JP-113-8657 Tokyo, Japan. Present address for KHT: Ecology and Genetics,Graduate School of Environmental Earth Science, Hokkaido Univ., Kita 10 Nishi 5,JP-060-0810 Sapporo, Japan (kazu@ees.hokudai.ac.jp).

The behaviour of Suillia flies on basidiocarps of Hebeloma radicosum was studied in central Japan. Hebeloma radico-sum is a peculiar fungus that fruits only on talpid mole middens, near the moles' nests. All insect species around selected basidiocarps of this mushroom species were observed, their behaviour studied, and identified in late October to early November 1992, and again briefly in 2001. During these periods, Suillia flies were seen on the basidiocarps, while other insect species were rarely observed. Usually one Suillia fly (male) occupied one basidio-carp and prevented other conspecifics from occupying the same basidiocarp. This appeared to be pre-mating territorial behaviour. Larval stages of Suillia are known to be mycophagous, and the territorial behaviour is presumably performed to defend oviposition sites. This is the first report from Asia on ecological aspects of Suillia flies.

The use of the cyclopoid copepods Macrocyclops distinctus (Richard) Megacyclops viridis (Jurine) and Mesocyclops pehpeiensis Hu (Cyclopoida: Cyclopidae) as biological control agents against the dengue vector Aedes albopictus (Skuse) (Diptera: Culicidae) was evaluated. In the laboratory their predatory ability was highest against the younger instars of Ae. albopictus and none of the three copepods killed the fourth instar. Except for M. viridis, predatory ability was affected by the size of the container: the smaller the container, the higher the predation. A 4-month field test was conducted to examine the impact of these predators on wild Ae. albopictus. Thirty artificial containers were placed in a peridomestic area to allow Ae. albopictus colonization. We showed continuous and similar oviposition responses in treated and control containers. The densities of Ae. albopictus showed considerable short-term changes and were much reduced by the copepod species. Macrocyclops and the mixture of all three provided better Ae. albopictus control than either Megacyclops or Mesocyclops alone. When larval densities peaked in the control containers in August and September, the overall reduction due to the copepods was nearly complete. Mesocyclops inoculated alone had the highest population survival. However, the growth and survival of all the copepod species was poor when the three genera were mixed. Based on their performance and survival in the trial, Macrocyclops and Mesocyclops merit consideration as bio-control agents of Ae. albopictus.

The aim of this study was to determine the effects of the V-furrow no-till direct seeding (DS) management on diversity patterns of aquatic insects, terrestrial arthropods and plants in rice paddies. In DS fields, rice is sown in well-drained fields, and flooding is performed 1 month later than that in conventional transplanting rice fields. DS fields are then continuously flooded until harvesting, unlike in conventional fields where a midseason drainage is performed during summer. We observed that diversity patterns of the study organisms were affected by the farming systems. DS fields supported abundant and species-rich assemblages of water beetles and water bugs, presumably because of the high compatibility between the flooding period and the reproductive season of the insects, as well as the absence of seedling box-applied insecticide (clothianidin). The DS farming system positively affected several taxonomic groups (terrestrial arthropods such as Collembola and Araneae, and several endangered plant species), while it negatively affected plant species richness. DS farming enhanced the densities of two rice pest species (Nephotettix cincticeps and Lissorhoptrus oryzophilus). The large differences in the responses of different taxonomic groups to farming systems suggest that a combination of DS and conventional system is preferable to the use of either system alone, for the conservation of aquatic and terrestrial biodiversity in rice agro-ecosystems.

金沢大学理工研究域 自然システム学系, Preliminary field experiments were conducted to examine the exophagy of Aedes albopictus in peridomestic habitat by using three different types of experimental buildings in Nagasaki, Japan and Chiangmai, Thailand. The density of females collected by suction traps enhanced by CO2 was high inside net-walled buildings and at outdoor sites with vegetation. On the other hand, the densities inside a normal walled building and at outdoor sites without vegetation, the microclimate conditions of both of which were different from the outdoor sites with vegetation, were low. To evaluate the effect of blocking by walls for Ae. albopictus invading to feed, an additional experiment by using a bamboo hut with openings of different sizes in the walls was conducted in Thailand. As the opening in the walls was smaller, the difference in the number of females between inside and outside of the hut became significantly larger. Therefore, the effect of physical blocking by walls was suggested. We proposed the presence of vegetation, the difference in environmental conditions inside buildings from those in vegetation due to blocking, and physical blocking by walls for invasion as ecological factors influencing the exophagy of Ae. albopictus. (author abst.)

Anopheles flavirostris (Ludlow) from Lombok Island, Indonesia, was crossed with An. minimus species A (CM strain) from Thailand and species E (ISG strain), a new sibling species, from Japan, to determine genetic compatibility. We also compare the scanning micrographs of female cibarial armature of these three species. Both An. minimus CM and ISG females crossed with An. flavirostris males produced eggs without embryos. One An. flavirostris female crossed with an An. minimus CM male deposited unhatchable eggs with an 18% embryonation rate. The scanning micrographs of the cibarial armature clearly show significant differences among An. flavirostris and the two sibling species of the An. minimus complex. These results support the specific status of An. flavirostris. Previous records of An. minimus Theobald in this country are also discussed.

1. In nature various mechanisms that provide some refuges for inferior species to escape from competition act together to promote the species coexistence in a local community. We propose a method to evaluate simultaneously the relative importance of different mechanisms for the species coexistence, focusing on a mycophagous drosophilid community depending on a multispecies fungal host system, where two mechanisms – aggregation over patches of single fungal species and resource partitioning at the fungal species level – can act together. The data are based on the numbers of adult insects emerging from naturally occurring fungi collected from a temperate forest in northern Japan. 2. We confirm the finding of Sevenster & van Alphen (1996) that large patches are low-density refuges despite the large absolute numbers of competitors on them, and therefore adopt new measures for intra- and interspecific aggregations and the species-persistence criterion, which were developed by Sevenster (1996) to take account of variable patch sizes in calculating the aggregation measures. 3. The calculated measures are compared among three analyses for fungal resources: AR-analysis (the original data-set from multispecies fungal patches) in which both aggregation and resource partitioning can act together; R-analysis (combining the data for all patches of each fungal species) in which only resource partitioning at the fungal species level can act; and A-analysis (calculating the measures independently for each fungal species) in which only aggregation process can act as a coexistence mechanism. 4. Intraspecific aggregation over multispecies fungal patches is strengthened by both aggregation and resource partitioning processes. 5. We reconfirm the finding of Sevenster & van Alphen (1996) that interspecific associations are consistent over years, and support their claim that such consistent associations should be taken as real aspects of the community structure. 6. Measures for the persistence criterion (T), the ‘relative effect of competitor aggregation’, are less than unity, satisfying the necessary and sufficient condition for the species persistence, in most drosophilid species concerned; these tend to be smaller in AR-analysis than in R- or A-analysis, suggesting facilitation of the species coexistence by both aggregation and resource partitioning in the mycophagous drosophilid community studied. 7. Differences in T-value between AR- and R-analyses and between AR- and A-analyses may indicate relative contributions of aggregation and resource partitioning, respectively, to the species coexistence. We propose a method to compare various communities in a multi-dimensional space with regard to the relative importance of different coexistence mechanisms.