Identification of species of Diplogonoporus balaenopterae and D. grandis (Cestoda, Diphyllobothriidae)

Comparative study of diplogonadal diphillobothriids from different species of whalebone whales and from man (Japan) and analysis of literary data has made it possible to establish their identity. Only the species Diplogonoporus balaenopterae (L?nnberg, 1892 capable of infecting whalebone whales, dogs and man can be regarded as really existing. The species D. grandis (Blanchard, 1894) Lühe, 1899 is its synonym.     

Complete mitochondrial genomes of Diplogonoporus balaenopterae and Diplogonoporus grandis (Cestoda: Diphyllobothriidae) and clarification of their taxonomic relationships

Although the diplogonadic human tapeworm, Diplogonoporus grandis, has long been considered to be a synonym of the whale tapeworm, Diplogonoporus balaenopterae, the identity of the both species at the complete mitochondrial genomes and nuclear DNA levels has been not sufficiently undertaken to date. In the present study, to clarify the taxonomic relationships between D. balaenopterae and D. grandis at the molecular level, the complete mitochondrial genomes of both species were sequenced and compared. In addition, the genetic variation in the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) and the nuclear internal transcribed spacer-1 (ITS-1) region of the ribosomal RNA gene were examined. The complete mitochondrial genomes of D. balaenopterae and D. grandis consisted of 13,724 bp and 13,725 bp, respectively. These mitochondrial genomes contained 12 protein-coding, 22 transfer RNA and 2 ribosomal RNA genes and two longer non-coding regions. Except for Hymenolepis diminuta, the genomic organization in both species was essentially identical to that in other cestode genomes examined to date. However, differences were observed between Diplogonoporus and Diphyllobothrium species in abbreviated stop codons, sequences and the number of repeat units in the 2nd non-coding regions. The genetic differences observed in the mitochondrial genomes, cox1 and ITS-1 regions of both species were considered typical of intraspecific variation. In conclusion, D. balaenopterae is a taxonomically valid species and D. grandis is a junior synonym of D. balaenopterae based on the zoological nomenclature. Further, molecular-phylogenetic analysis confirmed that D. balaenopterae is more closely related to Diphyllobothrium stemmacephalum, the type-species of the genus Diphyllobothrium, and the taxonomical validity of the genera Diplogonoporus and Diphyllobothrium was also discussed.     

Isolation and identification of non-chlorinated phenylbenzotriazole (non-ClPBTA)-type mutagens in the Ho River in Shizuoka Prefecture, Japan

We previously identified 2-[2-(acetylamino)-4-amino-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA) congeners as major mutagens in water concentrates from several rivers that flow in three different areas, i.e. Kyoto, Aichi, and Fukui Prefectures, in Japan. In synthesis studies, these PBTAs were shown to be formed from corresponding dinitrophenylazo dyes via non-chlorinated derivatives (non-ClPBTAs). However, only non-ClPBTA-1, i.e. 2-[2-(acetylamino)-4-[bis(2-methoxyethyl)amino]-5-methoxyphenyl]-6-amino-4-bromo-2H-benzotriazole, had been detected as a minor contaminant in the Nishitakase River in Kyoto. In this study, analysis of mutagens in water concentrate from the Ho River, which flows through an area with a textile dyeing industry in Shizuoka Prefecture, Japan, allowed the isolation of four compounds (I, II, III, and IV). These four mutagens were identified as 2-[2-(acetylamino)-4-[N-(2-cyanoethyl)ethylamino]-5-methoxyphenyl]-6-amino-4-bromo-2H-benzotriazole (non-ClPBTA-2), 2-[2-(acetylamino)-4-[(2-hydroxyethyl)amino]-5-methoxyphenyl]-6-amino-4-bromo-2H-benzotriazole (non-ClPBTA-3), 2-(2-acetylamino-4-amino-5-methoxyphenyl)-6-amino-4-bromo-2H-benzotriazole (non-ClPBTA-4), and 2-[2-(acetylamino)-4-(diethylamino)-5-methoxyphenyl]-6-amino-4-bromo-2H-benzotriazole (non-ClPBTA-7) by spectral data and co-chromatography using synthesized standards. Non-ClPBTA-3 and -7 were highly mutagenic in Salmonella typhimurium YG1024, inducing 159,000 and 178,000 revertants/microg, respectively, in the presence of S9 mix. Like PBTAs, non-ClPBTAs might have been produced from azo dyes during industrial processes in dyeing factories and released into rivers.     

Seroepidemiological study of norovirus infection in Aichi Prefecture, Japan

The serological prevalence of IgG antibody to seven NoV strains (GI.1, GI.4, GII.3, GII.4, GII.10, GII.12 and GII.15) among inhabitants aged 1–62 years of Aichi Prefecture, Japan was studied. Age-related seroprevalence was measured by ELISA using baculovirus-expressed recombinant VLP antigens. Seropositive rates for all seven VLP antigens gradually increased with age. Among the tested antigens, the highest seropositive rate was for the GII.4 strain. This result is consistent with the recent epidemic of NoV infection due to GII.4 strain in Japan.     

Rapid development of resistance to diamide insecticides in the smaller tea tortrix,Adoxophyes honmai (Lepidoptera: Tortricidae), in the tea fields of Shizuoka Prefecture,Japan

We investigated the susceptibility of the smaller tea tortrix, Adoxophyes honmai Yasuda, to diamide insecticides in the Shimada-Yui tea fields in Shizuoka Prefecture, Japan, from 2006 to 2011. By 2011, the insects had developed significant resistance even to concentrations far above the registration concentrations of two diamides, flubendiamide and chlorantraniliprole. The lethal concentration 50 (LC₅₀) values of flubendiamide showed a rapid annual increase from 16.2 ppm in 2007 to 161 ppm in August 2011, exceeding the registration concentration of 100 ppm in 2010 and 2011. The LC₅₀ values of chlorantraniliprole increased sharply from 25.3 ppm in 2010 to 98.8 ppm in August 2011, exceeding the registration concentration of 50 ppm. The LC₅₀ values for flubendiamide and chlorantraniliprole at 10 days after treatment in insects collected in August 2011 were 105-fold and 77.2-fold higher, respectively, than those in a susceptible strain.     

Seasonal occurrence of Laodelphax striatellus (Hemiptera: Delphacidae) in a rice-forage crops mixed cropping area in central Kyushu,Japan

The small brown planthopper, Laodelphax striatellus (Fallén) is an important pest of rice in East Asia because it is a vector of rice stripe virus. In this study, we examined the seasonal occurrence of L. striatellus in an agricultural area in central Kyushu in which cropping systems have been changing since the 1970s. The first generation of L. striatellus emerged in the spring, not only on barley, oats, and Italian ryegrass but also on spring crops of forage maize. The second generation of L. striatellus adults emerged in forage maize fields in July, after harvesting of winter crops of barley, oats, and Italian ryegrass. These results suggest that spring crops of forage maize are important hosts of L. striatellus from spring to early summer. The overwintering generation of L. striatellus was collected from rice ratoon, suggesting this is a favorable host for L. striatellus during winter. The appearance of these novel hosts may be a factor in the recent re-emergence of L. striatellus in central Kyushu.     

Two Taenia species found in Japan, with new distribution record of Taenia polyacantha Leuckart, 1856 (Cestoda: Taeniidae)

In an epidemiological survey for Echinococcus multilocularis in rodents and insectivores from the northernmost part of the central mainland of Japan (Honshu), two taeniid species, Taenia crassiceps and Taenia polyacantha, were found in Microtus montebelli and Apodemus argenteus, respectively. The latter is the first record of distribution in Japan, and the former is the second after its first recovery from the central part of Japan. Although we have found neither larval nor strobilar stage of E. multilocularis there, discovery of these taeniid species, having overlapping global distribution with E. multilocularis in red foxes, Vulpes vulpes as well as multiple occurrences of hydatid patients having no history of visits to the endemic areas shows the possibility that the life-cycle of E. multilocularis might be maintained at least in the northernmost part of Honshu.     

Geography and host specificity: two forces behind the genetic structure of the freshwater fish parasite Ligula intestinalis (Cestoda: Diphyllobothriidae)

Parasite species with global distributions and complex life cycles offer a rare opportunity to study alternative mechanisms of speciation and evolution in a single model. Here, genealogy and genetic structure, with respect to geography and fish host preference, have been analyzed for Ligula intestinalis, a tapeworm affecting freshwater fish. The data analyzed consisted of 109 tapeworms sampled from 13 fish host species in 18 different localities on a macrogeographic scale. Two mitochondrial genes, cytochrome oxidase subunit I and cytochrome B, and the nuclear sequence of intergenic transcribed spacer 2 (ITS2) were used for the genetic reconstruction. Different evolutionary patterns were found at the local and at the global geographic scales. On a local scale, the flat genetic structure was mainly attributed to contiguous range expansion. Migrating birds are the most likely cause of the homogenisation of the whole population, preventing the creation of significant genetic barriers. By contrast, on a global scale, genetically distant and well-separated clusters are present in different geographic areas. Reproductive isolation was found even between clades living in sympatry and infecting the same definitive host, suggesting the existence of efficient biologically determined genetic barriers, and thus possibly separate species. Although the ITS2 sequences were found to display considerable intragenomic variability, their relationships were generally in good agreement with the topology derived from mitochondrial genes.     

Prevalence of human immunodeficiency virus (HIV) infection among hemophiliacs in Fukuoka, Japan

To determine when the hemophiliacs in Fukuoka prefecture, Japan, first became positive for antibodies, we tested human immunodeficiency virus (HIV) antibodies on serum samples obtained from 1976-1987 stored at -30 C. Fifteen out of 64 hemophilia A patients (23.4%), five out of 11 hemophilia B patients (45.5%), but none of 17 patients with von Willebrand's disease (0%) were positive for HIV antibodies. In this series, two with hemophilia A became positive for HIV antibodies for the first time in 1983, and in 1984 another four with hemophilia A and one with hemophilia B became positive.     

Ticks (Acari: Ixodidae) from medium-sized to large mammals in Ehime Prefecture, Japan

Ixodid ticks were collected from medium-sized to large mammals in Ehime Prefecture, Shikoku, Japan. Ten species of ticks (Amblyomma testudinarium, Dermacentor taiwanensis, Haemaphysalis flava, H. formosensis, H. hystricis, H. longicornis, H. megaspinosa, Ixodes nipponensis, I. ovatus, and I. tanuki) were collected from a total of 29 mammals comprising 11 species. Haemaphysalis hystricis, a possible vector of Japanese spotted fever in Ehime prefecture, was collected from Canis lupus familiaris (domestic dog), Martes melampus melampus, and Sus scrofa leucomystax. This is a first report of H. hystricis from the domesticated dog in the endemic area of Japanese spotted fever. This suggests that it is necessary to pay attention to dogs as a host of the vector ticks for Japanese spotted fever control. Nyctereutes procyonoides and Ma. melampus are new hosts for A. testudinarium. Nyctereutes procyonoides, Mustela itatsi, and Lepus brachyurus are new hosts for H. formosensis. Martes melampus is a new host for H. hystricis.     

Photosynthetic and respiratory responses of Gracilaria vermiculophylla (Ohmi) Papenfuss collected from Kumamoto, Shizuoka and Iwate, Japan

The photosynthetic and respiratory responses to irradiance, salinity and temperature of the red alga, Gracilaria vermiculophylla, collected from Kumamoto, Shizuoka and Iwate in Japan were studied using an electronic Dissolved Oxygen sensor. The parameters derived from the photosynthesis versus irradiance relationship indicated the potential to acclimate to broad irradiance variations in all of the populations of G. vermiculophylla collected from these three sites. In addition, the light-saturated photosynthesis rate (P _max) and the dark respiration rate of all populations increased with increasing temperature up to 20–30°C, while the P _max decreased at 35°C. All populations also showed a broad variation of photosynthetic responses to salinity changes in the range from 10 to 30 psu. On the other hand, the population from Iwate showed high photosynthetic efficiency, especially in the temperature range of 5–10°C, and showed low values of saturation irradiance compared to the populations from Shizuoka and Kumamoto. These results suggest that there is greater potential to acclimate to low irradiance and low temperature in the population from Iwate compared to those from the Shizuoka and Kumamoto populations. However, the P _max of the populations from Iwate and Shizuoka was reached at 20°C and 25°C, respectively, while the Kumamoto population reached P _max at 30°C. This implies that the latter population has greater potential to tolerate higher temperatures than the former. Such characteristics in photosynthesis and respiration of G. vermiculophylla collected from the three locations probably indicate an acclimation to prevailing environmental conditions in their respective habitats.     

Geographical distribution of Metagonimus yokogawai and M. miyatai in Shizuoka Prefecture, Japan, and their site preferences in the sweetfish, Plecoglossus altivelis, and hamsters

Sweetfish, Plecoglossus altivelis, obtained from 18 rivers in Shizuoka Prefecture were examined for metacercarial infection of 2 flukes, Metagonimus yokogawai and Metagonimus miyatai. The infection rate and density of metacercariae in the fish were higher in eastern and western regions than in central region of the prefecture. After infection of hamsters with metacercariae derived from the scale, 98.7% of the adult worms obtained from the intestine was found to be M. miyatai. Conversely, from infection with metacercariae from the flesh, 90.0% of the worms was M. yokogawai. Since the worms had no exclusivity in the tissues, we conclude that the flukes have location preference with the former primarily preferring the scale, and the latter the flesh. Fish from two rivers located in adjacent areas in the western region had relatively a higher ratio of M. yokogawai in the scale relative to other rivers, suggesting an intraspecific genetic variation due to geographical isolation. On examination of adult worms in the hamster's intestine, M. yokogawai was mainly located towards the anterior part of the intestine, unlike M. miyatai, suggesting that in mammalian host too, the parasites have site preference.     

Redescription of Diesingium lomentaceum (Diesing, 1850) (Cestoda: Trypanorhyncha)

Ardeirhynchus spiralis (Rudolphi, 1809) n. g., n. comb. (syns Echinorhynchus spiralis, Prosthorhynchus spiralis and Plagiorhynchus spiralis), a parasite of herons (Ciconiiformes: Ardeidae), is redescribed on the basis of the holotype from Ixobrychus minutus and specimens from Ardeola ralloides (new host record) in Bulgaria. A. spiralis is a member of the family Polymorphidae and not of the Plagiorhynchidae in which it was previously classified. Ardeirhynchus n. g. is distinguished from the most morphologically similar genus, Arhythmorhynchus Lühe, 1911, by the position of the male genital system, which occupies the posterior 1/8-1/6 part of the trunk, the distribution of hypodermal nuclei in groups in the anterior part and in lateral rows along the length of the posterior part of the trunk, a considerably shorter neck, minute trunk spines and a terminal genital pore.     

Mycorrhizal fungi associated with Monotropastrum humile (Ericaceae) in central Japan

We explored the diversity of mycorrhizal fungi associated with Monotropastrum humile in the central part of Japan's main island. We collected 103 M. humile individuals from 12 sites with various forest types. We analyzed the DNA sequences of the internal transcribed spacer region from fungal and plant nuclear ribosomal DNAs to assess the genetic diversity of the fungi associated with M. humile roots and to position the plant with respect to known Monotropoideae groups, respectively. The plants formed a monophyletic clade with other members of M. humile but were separated from M. humile var. glaberrimum and other monotropes (97% bootstrap support). Of the 50 fungal phylotypes, 49 had best matches with the Russulales, and the other had highest similarity with the Thelephoraceae. Our phylogenetic analysis suggests that M. humile roots have a highly specialized association with fungal partners in the Russulaceae. Moreover, a few fungal phylotypes from the M. humile roots had positions neighboring those from Monotropa uniflora roots. These results indicated that the genetic diversity of mycorrhizal fungi of M. humile was highly specific to the Russulaceae, but with high diversity within that family, and that the fungi associated with M. humile differ from those associated with M. uniflora.     

Establishment and yearly/seasonal occurrence of the exotic coccidophagous ladybird <Emphasis Type="Italic">Cryptolaemus montrouzieri</Emphasis> (Coleoptera: Coccinellidae) in citrus groves in Shizuoka City,central Japan: a 5-year survey on adult numbers

Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) is a ladybird native to Australia, preying on mealybugs and soft scales, and has been utilized worldwide as a biological control agent. It has long been recognized that C. montrouzieri that was introduced into the main island of Japan had failed to become established. The present study monitored yearly and seasonal occurrence of C. montrouzieri adults in citrus groves at Shizuoka Prefectural Fruit Tree Research Center in Shizuoka City, central Japan in 2008–2012 by using sticky traps and beating citrus trees. Adults of C. montrouzieri were continuously captured for 5 and 4 years in a pesticide-free citrus grove and a neighboring reduced-pesticide grove, respectively. Larvae of C. montrouzieri were observed consuming a cottony scale, Pulvinaria aurantii Cockerell, on citrus trees. These results provide unequivocal evidence for the ladybird’s establishment in central Japan. The number of trapped ladybird adults exhibited four peaks a year: in mid-April, early to late June, mid-August, and late September to early October. Adult numbers in each grove varied largely across years, showing a great increase followed by a rapid decline during a period of 4 years. Factors affecting the seasonal/yearly occurrence of C. montrouzieri adults in citrus groves are discussed.