Vexans Nipponii Research Articles

Black light trap collections in Wangging county and Yanji city, Jilin Province, China, August 2006–2007

AbstractAdult mosquito surveillance was conducted using black light traps in August of 2006 and 2007 at Wangging county and Yanji city, Jilin Province, China to identify the distribution of anopheline mosquitoes in northern China. A total of 2459 female mosquitoes comprising three genera and eight species including Anopheles (Anopheles) lesteri, An. (Ano.) kleini, An. (Ano.) pullus, Culex inatomii, Cx. orientalis, Cx. pipiens, Cx. bitaeniorhynchus and Aedes vexans nipponii were collected. The most commonly collected species was An. kleini which had not been previously reported from China. Anopheles sinensis sensu stricto is commonly collected throughout China, but was not collected from these areas.

Seasonal prevalence of mosquitoes collected from light traps in the Republic of Korea, 2007

AbstractAdult mosquito surveillance was conducted using New Jersey light traps from 1 May to 15 October during 2007 at 14 US Army and three Air Force installations and two US Army training sites located in six provinces in the Republic of Korea to determine threshold levels to initiate pesticide applications based on trap indices. A total of 24 013 adult mosquitoes (19 763 [82.3%] females and 4250 [17.1%] males) comprising 16 species (including five members of the Anopheles Hyrcanus Group) and belonging to seven genera were collected. Females of the most commonly collected species were members of the Anopheles Hyrcanus Group (52.1%), followed by, Culex tritaeniorhynchus Giles (20.6%), Culex pipiens Coquillett (13.8%), and Aedes vexans nipponii (Theobald) (11.6%). Trap indices varied widely for species over their range, due in part, to geographical distribution and degree of association with urban or rural communities.

Seasonal prevalence of mosquitoes collected from light traps in the Republic of Korea, 2006

AbstractAdult mosquito surveillance was conducted during 2006 at 22 US Army and Air Force installations and two training sites located in six provinces in the Republic of Korea. Adult mosquitoes were collected in New Jersey light traps from 1 May through 15 October 2006 to determine threshold levels to initiate pesticide applications based on trap indices. In total 16 217 adult mosquitoes [13 612 (83.9%) females and 2605 (16.1%) males] comprising 16 species (including five members of the Anopheles sinensis Group) belonging to eight genera were collected. Females of the most commonly collected species were members of the Anopheles sinensis Wiedemann Group (58.9%), followed by Aedes vexans nipponii (Theobald) (21.3%), Culex tritaeniorhynchus Giles (11.8%) and Culex pipiens Coquillett (5.2%). Trap indices varied widely for species over their range, due in part, to their geographical distribution and degree of association with urban or rural communities.

Seasonal prevalence of mosquitoes collected from light traps in the Republic of Korea, 2005

AbstractAdult mosquito surveillance was conducted during 2005 at 22 US military installations and two training sites located in six provinces in the Republic of Korea. Adult mosquitoes were collected in New Jersey light traps from 1 May to 15 October to determine threshold levels to initiate pesticide applications based on trap indices. A total of 27 363 adult mosquitoes (22 368 [81.7%] females and 4995 [18.3%] males) comprising 15 species (including five members of the Anopheles sinensis group) belonging to seven genera were collected. The most common species collected were members of the Anopheles sinensis Wiedemann group (50.2%), followed by Culex tritaeniorhynchus Giles (30.6%), Aedes vexans nipponii (Theobald) (11.8%), and Culex pipiens Coquillett (6.3%) females. Trap indices varied widely for species over their range, due in part to geographical distribution and degree of association with urban or rural communities.

Results of mosquito collection from international aircrafts arriving at Narita International Airport, Japan and mosquito surveillance at the airport

Aircrafts arriving at Narita International Airport, Japan were inspected for mosquito vectors of human diseases accidentally introduced into the country. During 5 years from 2001 to 2005 a total of 2, 161 aircrafts were inspected and 28 adult mosquitoes were found from 26 (1.2%) of the aircrafts. Thirteen aircrafts with mosquitoes came from North and South America, 12 aircrafts from Asia and Oceania, and one aircraft from Europe. The mosquito species found in the aircrafts were Culex pipiens complex, Anopheles sinensis, Aedes vexans nipponii, Cx. tritaeniorhynchus. Mosquito species occurring at the government ordinance area of Narita International Airport were examined by dipping collection of larvae, ovitraps, light traps, and dry ice traps, and identified into 12 taxa belonging to 8 genera. In the terminal building of Narita International Airport, adults Cx. pipiens complex were collected year round suggesting the establishment of foreign vector mosquitoes accidentally introduced from tropical/subtropical areas through aircrafts. All of 15, 231 adult mosquitoes examined were negative for 5 mosquito-borne diseases ; yellow fever, dengue fever, Japanese encephalitis, West Nile fever, and malaria.

Seasonal prevalence of mosquitoes collected from light traps with notes on malaria in the Republic of Korea, 2004

AbstractAdult mosquito surveillance was conducted during 2004 at 29 US military installations and training sites located in six provinces in the Republic of Korea. Adult mosquitoes were collected in New Jersey light traps and Magnet traps from 1 May through 15 October to determine threshold levels to initiate pesticide applications and to identify malaria infection rates at selected army installations and training sites. A total of 89 206 adults (78 454 [87.9%] females and 10 752 [12.1%] males) comprising 20 species (including five members of the Anopheles Hyrcanus Group) and belonging to seven genera were collected. The most common species collected were members of Culex tritaeniorhynchus Giles (49.4%) and Anopheles sinensis Wiedemann complex (39.1%), followed by Culex pipiens Coquillett (6.1%) and Aedes vexans nipponii (Theobald) (4.2%). Trap indices varied widely for species over their range, due in part to geographical distribution and degree of association with urban communities.

Seasonal prevalence of mosquitoes collected from light traps in the Republic of Korea in 2003

AbstractSurveillance of adult mosquitoes was conducted at 29 US military installations and training sites in six provinces in the Republic of Korea during 2003. Adult mosquitoes were collected in New Jersey light traps and dry ice‐baited New Jersey light traps from 1 May to 15 October. Mosquito surveillance was conducted to determine threshold levels to initiate pesticide applications and identify malaria infection rates at selected army installations and training sites. A total of 42 024 adult mosquitoes (32 594 females [77.6%] and 9430 males [22. 4%]) comprising 14 species and Anopheles sinensis s.l. (a complex of five species), representing seven genera, were collected. The most common species were members of the Anopheles sinensis Wiedemann complex (54.9%), followed by Aedes vexans nipponii (Theobald) (19.0%), Culex pipiens Coquillett (14.3%) and Culex tritaeniorhynchus Giles (10.6%). Trap indices varied widely for species over their range, due in part to geographical distribution and degree of association with urban communities.

STUDY OF FLYING HEIGHT OF CULICID SPECIES IN THE NORTHERN PART OF THE REPUBLIC OF KOREA

The vertical distribution of mosquitoes (Diptera, Culicidae) was evaluated in Paju County in northern South Korea by using Centers for Disease Control and Prevention (CDC) miniature light traps with ultraviolet light and dry ice (CO2) as attractants. CDC traps were placed at 1, 3 and 5 m above the ground near rice paddies in a relatively open agricultural ara. Traps wer hung on two scaffold towers (6 m height) spaced approximately 300 m aprt. Each trap operated 9 nights from August 3 to 16, 2002, and collected 9,971 mosquitoes: Aedes Vexans nipponii, 145.2; Culex tritaeniorhynchus, 34.9; Anopheles sinensis, 21.3; and Culex pipiens, 17.3 female mosquitoes/trap/night. Average flight height was calculated from the total number of catches in both stations. Overall, Cx. pipiens (2.52 +/- 0.35 m) was found to be the highest flying species followed by An. sinensis (2.04 +/- 0.79 m), Ae. vexans nipponii (1.96 +/- 0.44 m), and Cx. tritaeniorhynchus (1.76 +/- 0.68 m), respectively. Although no significant difference in flying height among species was encountered, every species showed their own flight preference range, matching with their host preference.

Seasonal Prevalence of Mosquitoes Collected from Light Traps in the Republic of Korea, 2002

ABSTRACTAdult mosquito surveillance was conducted during 2002 at 30 US military installations and training sites located in six provinces in the Republic of Korea (ROK). Adult mosquitoes were collected in New Jersey and dry ice ‐baited New Jersey light traps from 1 May through 15 October. Mosquito surveillance was conducted to determine threshold levels to initiate pesticide applications and identify malaria infection rates at selected Army installations and training sites. A total of 100,617 adults [82,410 (81.9%) females and 18,207 (18.1%) males] comprising 17 species and 7 genera were collected during 2002. The most common species collected were Culex tritaeniorhynchus Giles (49.5%), Anopheles sinensis Wiedemann (30.9%), Culex pipiens Coquillett(11.8%) and Aedes vexans nipponii (Theobald) (7.1%). Trap indices (TIs) varied widely for species over their range, due in part, to geographical distribution and degree of association with urban communities. Anopheles sinensis were collected at the same level while Culex tritaeniorhynchus increased by 27.2% in 2001, due in part to very high populations of Culex tritaeniorhynchus at Gunsan Air Base. The weekly population densities for some species were variable for each of the years, apparently as a result of variable annual weather conditions. None of Anopheles sp. assayed for plasmodium vivax (Pv) malaria infections by Enzyme Linked Immunosorbent Assay (ELISA) were positive.

Seasonal Prevalence of Mosquitoes Collected from Light Traps in the Republic of Korea, 2001

ABSTRACT Adult mosquito surveillance was conducted during 2001 at 28 US military installations and training sites located in five provinces in the Republic of Korea (ROK). Adult mosquitoes were collected in New Jersey and dry ice‐baited CDC‐type light traps from 1 May through 15 October. Mosquito surveillance was conducted to determine threshold levels to initiate pesticide applications and identify malaria infection rates at selected Army installations and training sites. A total of 61,584 adults [45,814 (74.4%) females and 15,770 (25.6%) males] comprising 17 species and 7 genera were collected during 2001. The most common species collected were Anopheles sinensis Wiedemann (36.3%), Aedes vexans nipponii (Theobald) (23.1%), Culex tritaeniorhynchus Giles (22.3%) and Culex pipiens Coquillett (17.6%). Trap indices (TIs) varied widely for species over their range, due in part, to geographical distribution and degree of association with urban communities. During 2001, the TI for An. sinensis was 19.6 females/trap night compared to years 1999 and 2000, when the TI for the Munsan area was 1.4 and 2.9 times (27.7 and 57.4 TI) greater, respectively. The weekly population densities for some species were variable for each of the years, apparently as a result of variable annual weather conditions. None of the 16,302 Anopheles sinensis assayed for plasmodium vivax (Pv) malaria infections by Enzyme Linked Immunosorbent Assay (ELISA) were positive.

Seasonal Prevalence of Mosquitoes Collected from Light Traps in Korea (1999‐2000)

ABSTRACT Adult mosquito collections were conducted from 1999 through 2000 at 29 US military installations located in six provinces in the Republic of Korea (ROK). Adult mosquitoes were collected in New Jersey light traps from 15 May to 15 October each year. Adult mosquito surveillance was conducted to determine the appropriate time for pesticide applications at each of the Army installations. A total of 68,051 and 62,526 adults were collected in 1999 and 2000 respectively, comprising 53,983 (79.3%) females and 14,068 (20.7%) males in 1999, and 50,274 (80.4%) females and 12,252 (19.6%) males in 2000. A total of 19 species from 7 genera were collected. The most common species collected were Anopheles sinensis (34.2%), Culex tritaeniorhynchus (29.4%), Aedes vexans nipponii (18.2%) and Culex pipiens (16.8%). Anopheles sinensis were collected at the same level while Culex tritaeniorhynchus decreased by 6.2% in 2000. The weekly population densities for some species were variable for each of the years, apparently as a result of changing weather conditions.

健常キンイロヤブカからのチューリンゲン菌の分離とその二三の細菌学的性状について

健常キンイロヤブカからのチューリンゲン菌の分離とその二三の細菌学的性状について

Getah virus isolations from mosquitoes collected at two horse habitations in the western areas of Japan.

Adult female mosquitoes were collected biweekly over the period from May 11 to October 18, 1980 at two horse habitations in the western areas of Japan. A total of 13 virus strains was isolated in Vero and HmLu-1 cell cultures from 33, 604 mosquitoes. Of the 13 isolates, four were identified as Getah virus and the remaining 9 strains as Japanese encephalitis virus. Of the four virus isolates, three were recovered from 19, 465 mosquitoes of Culex tritaeniorhynchus in 200 pools, the field infection rate being 1:6, 488 at the Miyazaki Race Course (R. C.). Besides, one strain of Getah virus was recovered from 5, 897 mosquitoes of C. tritaeniorhynchus at the Ritto training Center (T. C.). In these studies, C. tritaeniorhynchus was collected predominantly with 85.1% and 54.5% at the Miyazaki R. C. and the Ritto T. C., respectively. On the other hand, Aedes vexans nipponii was captured in an extremely low proportion (less than 2%) from both collection sites. These results suggest that C. tritaeniorhynchus, which is occasionally infected with Getah virus, may act as a main vector of sporadic occurrence of equine Getah virus infection and A. vexans nipponii is a less important vector mosquito in the western areas of Japan.

Epidemiological studies on malayan filariasis in an inland area in Kyungpook, Korea 3. Ecological survey of vector mosquitoes of Brugia malayi.

The species composition, population density, and seasonal prevalence of vector mosquitoes in an inland area of Kyungpook province were studied, based on light trap and human bait trap collections, and the recent patterns of infestation for infective larvae of Brugia malayi in these vector hosts were investigated from May to November in 1985. Nine species in four genera of mosquitoes were collected by light trap, human bait trap, and/or by nets. Anopheles sinensis Wiedemann was the most abundant species collected by light traps during this year. Culex tritaeniorhychus Giles was the second abundant species, and Aedes vexans nipponii(Theobald) ranked third in total abundance. The earlist time when A. sinensis were found was the middle of May. At that time the temperature ranged from 14.3 degrees C to 22.8 degrees C and the humidity 53-90 per cent. The month of highest average nightly catch was July, when the temperature was betweeen 21.5 degrees C and 30.6 degrees C and the humidity 72-91 per cent. The peak time of biting activity of mosquitoes was different in each month, i.e. between 22:00-23:00 in July, and 20:00-21:00 hours in September, when the temperature was between 24.3 degrees C and 26.5 degrees C and the humidity 73-88 per cent in the field. While infective larvae of B. malayi were reported to have been found in one species of mosquito in 1975, no larvae were found in any species collected in this survey.

Seasonal prevalence of the vector mosquitoes of Japanese encephalitis virus in Kyungpook Province, Korea.

In order to determine the seasonal prevalence and population density of vector mosquitoes in Kyungpook province, a survey based on average number of female mosquito per trap-night, were carried out during the period from May to November in 1984. Among the 34,571 mosquitoes collected in Kyungsan county in animal shelters and human dwellings by light traps, approximately 45.0 % were Culex tritaeniorhynchus, 34.0 % per cent Culex pipiens pallens, and 19.0 per cent Anopheles sinensis. By comparison, distribution of mosquito species in Ankang town, in which Japanese encephalitis had been reported in the past, were quite different and A. sinensis was the most abundant species, being constituted in 75.8 per cent, followed by C. tritaeniorhynchus(23. 2 percent), and C. pipiens pallens(0. 6 per cent). In the general patten of seasonal prevalence, C. tritaeniorhynchus first appeared in mid-June, and trapped in large numbers during the periods from mid-August to early September, showing a simple sharply pointed one-peaked curve, while C. pipiens pallens was found to be active through almost the entire season showing irregular curves with several peaks. The trend of seasonal distribution of A. sinensis was similar to that of C. tritaeniorhynchus, but the earliest dates of appearance and disappearance different form that of C. tritaeniorhynchus. The results of hourly catches of mosquitoes by human baited traps have clearly shown the differences in the biting rhythm among the vector mosquitoes of this province, such as the facts that C. tritaeniorhynchus and A. sinensis are rather constantly active all through a night with more or less inconspicuous peaks twice a night, while C. pipiens pallens exhibits an irregular curve, and the numbers of A. vexans nipponii, C. vagans and Armigeres subalbatus are very small and are not sufficient for estimating the biting rhythm. Four genera and fourteen species of larval mosquitoes collected from eighteen kinds of habitats which classified according to the categories followed by Bates(1949). The main breeding sites contributing to peak C. tritaeniorhynchus adult densities in this surveyed areas were evidently ricefields, ground pools, puddles and swamps and marshes, etc. Summarizing the results, this study indicated that the highest population density of C. tritaeniorhynchus was encountered in late August and early September, showing simple sharply pointed one-peaked curve.

Getah virus in several species of mosquitoes

Vector competence of Aedes (Ae.) vexans nipponii (nip.) and Culex (Cx) tritaeniorhynchus for Getah virus was compared after incubation at 28 °C and 20 °C. Marked differences existed between Ae. vexans nip. strains Sapporo and Cx tritaeniorhynchus strain Kyoto in infection and transmission rates following ingestion of blood meals containing several concentrations of Getah virus. Simultaneous comparison of infectivity also revealed that infection rates of Ae. vexans nip. strains Sapporo (74%) and Shizunai (68%) were higher than those of Cx tritaeniorhynchus strain Kyoto (44%). No significant differences were seen in infection rates between three strains of Cx tritaeniorhynchus or between two strains of Ae. vexans nip. Getah virus propagated and was transmitted in Ae. vexans nip. as rapidly at 20 °C as at 28 °C. Following seven days' incubation both at 20 °C and 28 °C, Ae. vexans nip. was capable of transmitting the virus. 14 days' incubation at 20 °C were needed for Cx tritaeniorhynchus to acquire the same capability. Ae. japonicus, Ae. aegypti, Ae. albopictus, Cx pipens pollens, Armigeres subalbatus and Tripteroides bambusa were also susceptible to Getah virus infection.

Collection Of Adult And Larval Mosquitoes In U.S. Army Compounds In The Republic Of Korea During 1979~1983.

This paper is the result of adult female mosquito and larval collection in U.S. Army Installations in Korea from 1979 to 1983. New Jersey light traps ere operated for ault collection from May to October. The primary concern of this surveillance is to determine when to recommend insecticide spraying for mosquito control in the Army areas. The 5th Preventive Medicine Unit have developed an "index" level of female mosquitoes in a light trap similar to other U.S.Army Agencies in other parts of the world. When 10 female mosquitoes are reached on two consecutive trap-night, or 5 known vector females are collected, fogging is recommended in the trap areas. Mosquito collections were conducted in 12 U.S. Army areas by operating 39 New Jersey light traps. Mosquitoes collected from the areas were identified to be 17 species comprising 3 genera. Anopheles sinensis(40%). Culex tritaeniorhyncus(31%), Aedes vexans nipponii(19%), and Culex pipiens pallens(10%) appeared to be the most common species in the area. The species, population density and monthly appearance of adult mosquitoes were found to be almost the same in the all provinces involved. And Japanese encephalitis vector mosquitoes, Culex tritaeniorhyncus, showed their seasonal fluctuation from July to September with a peak in August each year. 3. Larval habitats confirmed in the Army areas were categorized into 16 types as shown in Table The mosquito larvae collected in those habitats were identified to be 15 species representign 4 genera. Most breeding sites in the Army areas were those which are activated during the wet season. More mosquitoes were collected from the Kyungki province than from the other provinces. The reason for more collection of mosquitoes from military installations in the Kyungki provinces appears to be the geographic characteritics surrounded by rice fields, marshes and other stagnant water areas.

Getah virus in Aedes vexans nipponii and Culex tritaeniorhynchus: vector susceptibility and ability to transmit.

Vector competences of Aedes (Ae.) vexans nipponii (nip.) and Culex (Cx.) tritaeniorhynchus to Getah virus were assessed by using a membrane feeding technique. The Getah virus was present at high titer in both species of mosquitoes after 21 days of extrinsic incubation at 28 degrees C. Infection rates on 21 post-feeding were 100 per cent (4/4) for Ae. vexans nip. at a virus dosage of 10(5.3) PFU/ml and 60 per cent (3/5) for Cx. tritaeniorhynchus at similar virus dosage. More than 10(3.5) PFU of virus was detected in salivary glands of both species of mosquitoes on day 21 of extrinsic incubation. Forty percent (2/5) of Ae. vexans nip. transmitted the virus into serum-agar after ingesting 10(4.3) PFU/ml of virus blood mixture. In experiments with Cx. tritaeniorhynchus ingesting 10(7.5) PFU/ml of virus blood mixture, 57 per cent (4/7) were able to transmit the virus to suckling mice and 59 per cent (10/17) transmitted the virus into serum-agar.

八重山群島の蚊科に関する研究 : 8 与那国島の蚊について

A survey was carried out to clarify the mosquito fauna of Yonagunijima located between Iriomote-jima and Taiwan. The mosquitoes were collected five times trom June 1977 through August 1981. In total, 26 species of 9 genera were recorded in the present survey. Among them, following 15 species were recorded for the first time from Yonagunijima : Mimomyia elegans, Mansonia uniformis, Uranotaenia ohamai, Uranotaenia annandalei, Aedes baisasi, Aedes vexans nipponii, Aedes lineatopennis, Culex nigropunctatus, Culex infantulus, Culex bicornutus, Culex pallidothorax, Culex ryukyensis, Culex bitaeniorhynchus, Culex tritaeniorhynchus, and Culex vagans. Tripteroides bambusa yaeyamensis, Aedes riversi, Culex bicornutus and Culex in-fantulus were predominant species and Aedes riversi was the most voracious biter in the forest area. Aedes vexans nipponii, Anopheles sinensis and Culex tritaeniorhynchus were commonly found in paddy fields and swamps, and Aedes albopictus and Culex pipiens quinquefasciatus were predominant in artificial containers and the most voracious biter around dwelling area. The important vector mosquitoes, Anopheles minimus and Aedes aegypti which were recorded before in this island, were not found in the present survey.

生駒山頂における蚊の採集成績, 特にコガタアカイエカ Culex tritaeniorhynchus summorosus の生理的年令について

From 1968 to 1971,mosquitoes were collected on the top of Mt. Ikoma, 642m above sea level by using a dry ice light trap, for one hour after sunset once a week during the period from June to September. The unfed females of Culex tritaeniorhynchus summorosus collected in 1970 were dissected to determine the physiological age composition and to observe the developmental stage of follicles. For comparison, similar surveys were conducted in paddy fields at three sites on the Osaka plain. 1) On the top of Mt. Ikoma, 9 species of mosquitoes were found. C. tritaeniorhynchus summorosus was the dominant species throughout the four years, followed by Anopheles sinensis and Aedes vexans nipponii. 2) Although the pattern of seasonal prevalence of C. tritaeniorhynchus summorosus females at the top of Mt. Ikoma is similar to that on the Osaka plain, the number in the former site generally tends to increase later and decrease earlier than in the latter site. 3) Even at the top of Mt. Ikoma, many parous females of C. tritaeniorhynchus summorosus were found. They were, for the most part, uniparous, with a few biparous. The greater the number of mosquitoes collected, the lower the parous rates. 4) The percentages of females with follicles at IIb or more advanced stages were generally higher both in nulliparous and uniparous females on Mt. Ikoma being apart from paddy fields than on the Osaka plain.