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ABSTRACT: We describe and illustrate for the 1st time the pupa and larva of adult female Ficalbia ichiromiyagii based on specimens collected from a swamp forest in Otomi, Iriomote Island, Ryukyu Archipelago, Japan. The pupa has a trumpet that is 6.25 times its breadth at halfway, with a long meatal cleft line; setae 6-I, II considerably long, usually single or bifid; median caudal seta absent; and paddle edge serrated only on the outer apical half. The larva is characterized by dark pigmentation of the head and siphon, seta I-C elongate and spiniform, usually with a short lateral spine on the inner basal side and siphon with 1 pecten spine and conspicuous seta 1-S at the base. The immature stages were found only in undisturbed jungle swamps with dense vegetation.
Journal of the American Mosquito Control Association 12/2012; 28(4):279-85. · 0.91 Impact Factor
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ABSTRACT: The bionomics of the mud lobster-hole mosquito Aedes (Geoskusea) baisasi in the Ryukyu Archipelago, Japan, was studied in the field and in the laboratory. The studies included the natural habitat, seasonal appearance, flight activity, mating behavior, resistance of eggs to desiccation, and breeding periods of the immature stages of this species. The burrow systems made by the mud lobster Thalassina anomala were excellent as breeding and resting habitats for both the immature and adult stages of the mosquito.
Journal of the American Mosquito Control Association 09/2011; 27(3):207-16. · 0.91 Impact Factor
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ABSTRACT: We studied the prevalence of avian Plasmodium in 509 mosquitoes of 9 species collected from the Ishigaki and Iriomote islands in the Yaeyama Archipelago, located southwest from the mainland of Japan. Two identical avian Plasmodium lineages were detected from Culex (Culiciomyia) nigropunctatus. Detected lineages were phylogenetically classified into different clade to avian Plasmodium lineages from birds and mosquitoes in the mainland of Japan but identical to a lineage detected from a resident bird, White-breasted Waterken (Amaurornis phoenicurus). This is the first detection of avian Plasmodium DNA from mosquitoes in the Yaeyama Archipelago and suggested that resident birds might have been infected with an avian Plasmodium lineage specific to the studied area and C. nigropunctatus could be the candidate vector mosquito species.
Journal of Veterinary Medical Science 07/2011; 73(11):1521-5. · 0.85 Impact Factor
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ABSTRACT: During an 11-year study period (1999-2010) on the islands of the Ryukyu Archipelago, Japan, 20 mosquito species were identified. The results revealed new records of species hitherto not reported on these islands. This contribution updates the mosquito fauna of the various islands of the Ryukyu Archipelago.
Journal of the American Mosquito Control Association 06/2011; 27(2):149-52. · 0.91 Impact Factor
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ABSTRACT: Internal transcribed spacer regions of ribosomal DNA were sequenced, and new species-specific primers were designed to simplify the molecular identification of five morphologically related subgenus Stegomyia mosquito species--Aedes aegypti, Ae. albopictus, Ae. riversi, Ae. flavopictus, and Ae. daitensis--found in the Ryukyu Archipelago, Japan. Each newly designed primer was able to amplify a species-specific fragment with a different size. Conditions for multiplex PCR were optimized to identify all five species in a single PCR. This method is a convenient tool for entomological field surveys, particularly in arbovirus endemic/epidemic areas where some of these species coexist.
Japanese journal of infectious diseases. 09/2010; 63(5):312-6.
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ABSTRACT: We used two mitochondrial loci (nicotinamide adenine dinucleotide dehydrogenase subunit 4 and cytochrome oxidase II) and a nuclear locus (28S-D2 spacer) for a total of 1337 bp to evaluate the relationships among the four subspecies of Aedes (Finlaya) japonicus Theobald. Ae. j. japonicus was recently introduced into the United States and has been expanding rapidly. We also included in our analysis a morphologically very closely related species, Aedes (Finlaya) koreicus Edwards, as well as three more distantly related species: Aedes (Finlaya) togoi Theobald, Aedes (Finlaya) hatorii Yamada, and Aedes (Aedimorphus) vexans Meigen. We found that the four subspecies in the Ae. japonicus complex are genetically quite distinct but seem to form a monophyletic group that surprisingly also includes Ae. koreicus, suggesting the need for a taxonomic reconsideration of the group. We also found that the two southern subspecies are more closely related to each other than to any of the remaining subspecies or to Ae. koreicus and may indicate an ancient north-south split of the lineage. Considering the overlap between Ae. j. japonicus and Ae. koreicus, but the stronger association between Ae. koreicus and humans, we are surprised it also has not expanded from its original range. As a proactive reaction to this possibility, we designed and tested a DNA-based rapid assay to differentiate Ae. koreicus from some of the species with which it may be confused in the United States. These Aedes are putative vectors of several important viral encephalitides.
Journal of Medical Entomology 07/2010; 47(4):527-35. · 1.76 Impact Factor
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ABSTRACT: A colony of Uranotaenia macfarlanei, a frog-feeding mosquito, was established in the laboratory. We report the bionomics of the species, as studied in the laboratory colony and in the field on Ryukyu Island, Japan. These include mating activity, feeding and resting habits, manner of oviposition, and egg, larval, and pupal periods.
Journal of the American Mosquito Control Association 03/2010; 26(1):99-102. · 0.91 Impact Factor
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ABSTRACT: Mosquito collections were carried out in August 2002 and July 2003 in Japan. Anopheles sinensis of the Hyrcanus Group, Myzomyia Series of Anopheles, was the most common species encountered. The distribution and habitats of 5 Anopheles Hyrcanus Group species are included. Eight species belonging to Aedes, Culex, and Uranotaenia were found associated with An. sinensis in rice paddies and a variety of other larval habitats.
Journal of the American Mosquito Control Association 01/2006; 21(4):458-63. · 0.91 Impact Factor
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ABSTRACT: During a mosquito survey in Ulu Gombak, Selangor, Peninsular Malaysia, October 2-16, 2003, we observed a peculiar oviposition habit of Armigeres flavus. This strange behavior is described and illustrated with photographs; although it is well known, no detailed description has been made previously.
Journal of the American Mosquito Control Association 01/2006; 21(4):466-8. · 0.91 Impact Factor
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ABSTRACT: Six mark-release-recapture experiments with Anopheles saperoi Bohart and Ingram were performed in the Yona Forest, northern Okinawa, Japan from June 1998 - November 1999, in order to estimate the gonotrophic cycle, survival, spatial distribution, flight range, and population size of An. saperoi. Adults and immature An. saperoi were collected from the Yona Forest area, taken to the laboratory and maintained under a controlled temperature and humidity in order to get a lager number of mosquitos for the mark-release-recapture experiments. Cohorts of An. saperoi females and males, numbering 3,016, 4,728, 327, and 2,603 for experiments I, II, III, and IV, respectively, were released. Cohorts of An. saperoi females only, numbering 709 and 586 for experiments V and VI, respectively, were also released. At the release site, the An. saperoi were marked with 0.5% fluorescent dye Rhodamine B and released. The recapture rates were 14 (0.93%), 33 (1.40%), 3 (1.83%), 32 (2.46%), 14 (1.97%), and 22 (3.75%) for experiments 1, II, III, IV, V, and VI, respectively. The length of the gonotrophic cycle of the recaptured An. saperoi females was estimated to be about 4 days, through the dissection method. The daily survival rate was estimated to be 0.73 by regression coefficient. The spatial distribution of marked, recaptured An. saperoi was similar to that of unmarked captured An. saperoi. The spatial distribution of the marked, recaptured An. saperoi among the collection site categories was significantly different. The observed differences in the frequency distribution of marked recaptured An. saperoi were considered to be due to the spatial variation of the habitats between the collection sites. The maximum flight range of the recaptured An. saperoi recorded in this study was 0.93 km. The population size of An. saperoi females in the study area was estimated by the Seber method to be 23,841, 1,182, 3,514, 5,679, and 9,238 for experiments I, II, IV, V, and VI, respectively. The estimated population size has a low standard of error using the Seber method, therefore we estimated our population size reasonably well. The population attributes and ecology of An. saperoi in the Yona Forest, in northern Okinawa are discussed.
The Southeast Asian journal of tropical medicine and public health 02/2005; 36(1):54-63. · 0.60 Impact Factor
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ABSTRACT: Ochlerotatus baisasi was observed and photographed feeding on a mudskipper (Periophthalmus argentilineatus). Origin of blood meals in the stomachs of female mosquitoes collected at burrows of land crabs and mud lobsters in the mangrove forests of Oura, Okinawa, and Komi, Iriomote (the Ryukyu Islands), was determined by enzyme-linked immunosorbent assay to be from a fish source.
Journal of the American Mosquito Control Association 07/2004; 20(2):134-7. · 0.91 Impact Factor
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ABSTRACT: Impregnated bed net (IBN) were used in 366 villages in the central and southern three provinces of Lao PDR from 1999 to 2000. It was confirmed that 81.0% of 40000 bed nets, which were donated by Japanese Grant Aid, were delivered within 2 years. The strengthening of information network systems in anti-malaria and strong relationship between community and local authorities ensured the success of operation in a short period. The number of patients and the slide positive rate of malaria decreased markedly in public health facilities in three provinces after the use of IBN. An entomological survey was conducted in Boualapha district, where malaria is endemic, to investigate the IBN efficacy on malaria vector. The density and parous rate of Anopeles dirus, which is the main malaria vector in the area, were markedly decreased in the village where IBN was used. This mosquito's behavior, which was baiting mainly humans during the time when the inhabitants sleep in the IBN, was considered to be advantageous in preventing malaria infection using by IBN. The area of distribution of A. dirus is similar to the high endemic area of malaria in Lao PDR. Thus, it is expected that the expansion of the IBN program in the southern provinces will lead to successful malaria control in subsequent years.
Acta Tropica 03/2004; 89(3):299-308. · 2.72 Impact Factor
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Takako Toma,
Ichiro Miyagi,
Takao Okazawa,
Jun Kobayashi,
Susumu Saita,
Ataru Tuzuki,
Hongkham Keomanila,
Simone Nambanya,
Samlane Phompida,
Miyoko Uza,
Minoru Takakura
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ABSTRACT: Anopheline mosquitos and their relation to malaria transmission were studied 3 times: in July and August, 1999; in December, 1999; and in August and September, 2000. The studies took place in the malaria endemic villages of Khammouane Province, southeast of Lao PDR. A total of 28 species were collected using human and animal bait. Human bait attracted predominantly Anopheles dirus and An. minimus, which were identified as vectors by the detection of sporozoites by dissection, PCR, and enzyme-linked immunosorbent assays for Plasmodium falciparum and P. vivax. The vectorial capacity of An. dirus was 0.009-0.428, while that of An. minimus was 0.048-0.186. The inoculation rate of An. dirus was 0.052-0.137 (Boualapha; August, 2000). An. nivipes and its sister species, An. philippinensis, were principally zoophilic, although a considerable number of the females were also attracted to human bait in the villages of the paddy field areas. An. philippinensis infected with oocysts of P. vivax was detected in a specimen collected by animal bait. These two species were considered as vectors in Khammouane Province. Four species, An. notanandai, An. sawadwongporni, An. willmori, and An. hodgkini, had not been recored before in Lao PDR. Information is provided on host preference and the nocturnal biting activities of common species and the incidence of malaria in the study areas.
The Southeast Asian journal of tropical medicine and public health 10/2002; 33(3):532-46. · 0.60 Impact Factor
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ABSTRACT: In order to provide basic data for evaluation of malaria control measures, a study on the knowledge and behavior of people regarding prevention of malaria was carried out in 8 malaria endemic villages in Khammouane Province of Lao PDR from 1999 to 2000. The total valid questionnaire respondents were 932, with a mean age of 32.3 +/- 14.9. 43.7% of the respondents were illiterate. About 44% of the respondents suffered from malaria in the past. About 55% of the illiterate group slept in mosquito nets, compared to 75.4% for the educated group. About 29% of the illiterate respondents had knowledge of malaria transmission by mosquito bites, compared to 48.8% for the educated groups. Out of 167 non-impregnated mosquito nets examined in two villages, 13 were in bad condition having holes or leaks and 39 female mosquitos including Anopheles spp were collected in these nets by early morning catches. Knowledge of malaria and behavior in relation to the prevention of malaria were significantly related to educational level. Health education as well as general education must be taken into account for communities in malaria endemic areas to become more involved in malaria control strategies.
The Southeast Asian journal of tropical medicine and public health 07/2002; 33(2):246-54. · 0.60 Impact Factor
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ABSTRACT: Aedes (Stegomyia) flavopictus Yamada is widely distributed in Japan and Korea. The species comprises three subspecies based on current morphological taxonomy: Aedes flavopictus in the Palearctic region of Japan, Ae. f downsi Bohart & Ingram from Amami and Okinawa Islands, and Ae. f miyarai Tanaka, Mizusawa & Ingram from Ishigaki and Iriomote Islands of the Ryukyu Archipelago. These subspecies designations are based on observations of a combination of several morphological characters, none of which, by itself is diagnostic for discriminating among the three subspecies. To further study the relationships in this group, we examined the nucleic acid sequence divergence in the internal transcribed spacer regions (ITSI and ITS2) of the ribosomal DNA gene array of Ae. flavopictus individuals collected at five sites from three geographic regions in Japan. Analysis of sequence data by distance and maximum parsimony methods produced phylogenetic trees that showed separation of the specimens into three major clades, corresponding to both subspecies and geographic region. These results were consistent with and support the current classification and geographic distribution of the three subspecies.
Journal of Medical Entomology 05/2002; 39(3):461-8. · 1.76 Impact Factor
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ABSTRACT: An ecological survey of dengue vector mosquitos was carried out in June 2000 in central Lao PDR. Two areas in Khammouane Province, Nongbok and Thakhek, were selected for the survey. Of the 7 mosquito species identified, Aedes aegypti was dominant in both study areas. The container index for Ae. aegypti in Nongbok was 51.8% and was significantly higher than that of Thakhek (40.2%); moreover, significant differences between the study areas were found with records to containers and to the conditions surrounding the houses. The key containers in Nongbok were water jars, whereas drums or small or discarded containers had the highest occurrence rate of Ae. aegypti in Thakhek. Mesocyclops aspericornis was found in large water jars and cement water tanks; no Aedes larvae were found at these sites. Strategy to control dengue vectors in the study areas was discussed.
The Southeast Asian journal of tropical medicine and public health 04/2002; 33(1):63-7. · 0.60 Impact Factor
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ABSTRACT: The susceptibility of three anopheline mosquitoes, Anopheles minimus Theobald, An. sinensis Wiedemann, and An. saperoi Bohart & Ingram, from the Ryukyu Archipelago to the rodent malaria, Plasmodium yoelii nigeriense was examined to find new vectors other than An. stephensi Liston for rodent malaria studies in the laboratory. The survival rate of the mosquitoes after feeding on mice infected with P. y. nigeriense was also examined. The Beech strain of An. stephensi from India was compared with An. minimus from Ishigaki Island, and An. sinensis and An. saperoi from Okinawa Island. Oocysts were first found on day 3 after feeding on mice infected with P. y. nigeriense in An. stephensi, on day 4 in An. minimus and An. saperoi, and day 6 in An. sinensis. From 8 to 14 d after feeding on malaria-positive mice, oocysts were present in 97.2-100% of An. stephensi, 85.7-100% of An. saperoi, 20-74.1% of An. minimus, and 12.5-13.3% of An. sinensis. The duration of oocyst occurrence in An. saperoi was 55 d, the longest among the anopheline mosquitoes used in this study. On day 8 after feeding, sporozoites were found in the salivary glands and heads of all the mosquitoes tested. From the 10th to 16th d, sporozoites were present in the salivary glands of 14.9% (range, 9.1-28.0%) of An. minimus, 47.3% (40.7-58.1) of An. saperoi, and 96.2% (94.1-97.2) of An. stephensi, but were absent in An. sinensis. Anopheles saperoi could be an excellent vector of P. y. nigeriense because it has comparatively high susceptibility and high longevity even after feeding on infected mice.
Journal of Medical Entomology 01/2002; 39(1):146-51. · 1.76 Impact Factor
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ABSTRACT: The egg morphology of Armigeres (Leicesteria) digitatus (Edwards) is described by the use of a scanning electron microscope. The biology of this species was studied using a laboratory colony. Eggs of this species are characterized by long, bristlelike tubercles at the anterior end, a micropyle located apicoventrally, and digitiform tubercles on the submerged part of the egg. Eggs were oviposited in masses directly on the water surface in newly cut bamboo internodes; they adhered to each other by the long, bristlelike tubercles. Females had an average of 45.5 ovarioles; 29.5 matured to stage V following a human blood meal. The average period from eclosion to adult emergence was 13.4 d in males and 14.3 d in females at 28°C.
Journal of Medical Entomology 08/1991; 28(5):606-610. · 1.76 Impact Factor
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ABSTRACT: Among the approximately 300 mosquito species known from the Philippines, 132 species belonging to 15 genera were identified from about 5,000 larval and adult specimens collected from the Philippines in 1981-82. Five species are reported from the Philippines for the first time: hmigeres pectinatus (Edwards), CuZex pez-@exus Leicester, Topomyia auriceps Brug, Toxorhynchites kempi (Edwards) and TX. Zeicesteri Theobald. In addition, 2 unknown species belonging to CX. KuZex) sp. in mimeticus Subgroup and cx. K'uZic
