Search

Larvae collected from an oak tree hole east of Brackettville, Kinney County, Texas, resulted in the collection of 3 species: Aedes triseriatus, Ae. zoosophus, and Haemagogus equinus. One larva and 1 female of Hg. equinus were recovered from this sample. This is the first report of Hg. equinus in Kinney County and the first report of this species being collected in Texas since 1962. Samples collected from other sites documented the presence of Ae. epactius, Culex nigripalpus, and Psorophora signipennis in Kinney County.

In 1920, Culex coronator was reported from San Benito, Texas, and later in Arizona, New Mexico, and Oklahoma. In 2005, this species was reported to be spreading across the southeastern USA. Now reported in 14 states, it has been found as far north as northern Oklahoma; Memphis, TN; and Suffolk, VA. The public health significance of Cx. coronator is not firmly established, even though it has been implicated as a potential vector of several arboviral diseases. This study aims to document additional Cx. coronator county-level records, to provide information about its continued expansion across the southern USA, and to provide a short research update into its vector potential. Data acquired through multistate collaborations and author collections resulted in 146 new county records from Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, and Texas. No new county records were presented for Arizona, New Mexico, Tennessee, or Virginia, which had previously reported this species. With these new data, this species has been documented in 386 counties in 14 states of the continental USA.

Aedes japonicus japonicus continues to spread westward and in this study, its presence is documented in 8 counties in Nebraska and in Bowie County, TX. In 1998, Ae. japonicus was collected in Connecticut, New Jersey, and New York for the 1st records of this species in North America. Except for Louisiana, it has been reported from all states that border or are east of the Mississippi River. In Canada, it has been reported in Ontario and all eastern provinces. In the Pacific Northwest, it has been reported in Washington, Oregon, and British Columbia, and in the midwestern states that do not border the Mississippi River, Kansas, Oklahoma, and South Dakota are the only states to have reported its presence in peer-reviewed journals.

The potential introduction of African swine fever virus (ASFV) into the United States has researchers evaluating routes of potential transmission and the establishment of sylvatic cycles. To help document vector-host associations related to ASFV transmission, the finding of O. turicata on a feral hog in Real County, Texas is reported.

The aim of this study was to consolidate mosquito information for 13 counties west of San Antonio, Bexar County, Texas, and to create a species checklist for future regional studies. The resulting checklist established a baseline for local mosquito-borne disease surveillance and can serve as a resource for public health officials. The 13 counties in this region were Bandera, Edwards, Kendall, Kerr, Kimble, Kinney, Maverick, Medina, Real, Sutton, Uvalde, Val Verde, and Zavala counties. To develop the checklist, county-level mosquito species data were extracted from 38 peer-reviewed publications and government documents, university reference collections, private collections, and the Texas Department of State Health Services' historical collection data. These data were combined with author field collections to create a comprehensive species list. Overall, 339 county-level records were documented through field studies with a total of 36 species representing 8 genera confirmed as being present in this region. An additional 14 species listed in historical surveillance records were not collected during this study.

Populations of Culex stigmatosoma and Cx. thriambus have been documented in the southwestern USA with a southward range extension to northern South America and Central America, respectively. Studies conducted in California indicate both species are potential vectors of West Nile virus. However, vector competence studies are lacking for other parts of the USA. During a multicounty regional surveillance study west of San Antonio, Texas, multiple errors were observed in the Texas distributional literature of these species. These errors involved incorrect distributional information in Texas and US publications. Evidence to correct these errant records was found upon further analysis of Texas literature and curated specimens. Therefore, the aims of this study were to present that evidence and then combine the corrected records with additional records from the Texas Department of State Health Services and from larval collections made during other Texas surveillance studies.

A novel technique was developed to control the microstructure evolution in Alloy 718 processed using Electron Beam Melting (EBM). In situ solution treatment and aging of Alloy 718 was performed by heating the top surface of the build after build completion scanning an electron beam to act as a planar heat source during the cool down process. Results demonstrate that the measured hardness (478 ± 7 HV) of the material processed using in situ heat treatment similar to that of peak-aged Inconel 718. Large solidification grains and cracks formed, which are identified as the likely mechanism leading to failure of tensile tests of the in situ heat treatment material under loading. Despite poor tensile performance, the technique proposed was shown to successively age Alloy 718 (increase precipitate size and hardness) without removing the sample from the process chamber, which can reduce the number of process steps in producing a part. Tighter controls on processing temperature during layer melting to lower process temperature and selective heating during in situ heat treatment to reduce over-sintering are proposed as methods for improving the process.

The distribution of

Additive manufacturing (AM), widely known as 3D printing, is a method of manufacturing that forms parts from powder, wire or sheets in a process that proceeds layer by layer. Many techniques (using many different names) have been developed to accomplish this via melting or solid-state joining. In this review, these techniques for producing metal parts are explored, with a focus on the science of metal AM: processing defects, heat transfer, solidification, solid-state precipitation, mechanical properties and post-processing metallurgy. The various metal AM techniques are compared, with analysis of the strengths and limitations of each. Only a few alloys have been developed for commercial production, but recent efforts are presented as a path for the ongoing development of new materials for AM processes.

A computational modeling approach to simulate residual stress formation during the electron beam melting (EBM) process within the additive manufacturing (AM) technologies for Inconel 718 is presented in this paper. The EBM process has demonstrated a high potential to fabricate components with complex geometries, but the resulting components are influenced by the thermal cycles observed during the manufacturing process. When processing nickel based superalloys, very high temperatures (approx. 1000 °C) are observed in the powder bed, base plate, and build. These high temperatures, when combined with substrate adherence, can result in warping of the base plate and affect the final component by causing defects. It is important to have an understanding of the thermo-mechanical response of the entire system, that is, its mechanical behavior towards thermal loading occurring during the EBM process prior to manufacturing a component. Therefore, computational models to predict the response of the system during the EBM process will aid in eliminating the undesired process conditions, a priori, in order to fabricate the optimum component. Such a comprehensive computational modeling approach is demonstrated to analyze warping of the base plate, stress and plastic strain accumulation within the material, and thermal cycles in the system during different stages of the EBM process.

Site specific control of the crystallographic orientation of grains within metal components has been unachievable before the advent of metals additive manufacturing (AM) technologies. To demonstrate the capability, the growth of highly misoriented micron scale grains outlining the letters D, O and E, through the thickness of a 25·4 mm tall bulk block comprised of primarily columnar [001] oriented grains made of the nickel base superalloy Inconel 718 was promoted. To accomplish this, electron beam scan strategies were developed based on principles of columnar to equiaxed transitions during solidification. Through changes in scan strategy, the electron beam heat source can rapidly change between point and line heat source modes to promote steady state and/or transient thermal gradients and liquid/solid interface velocity. With this approach, an equiaxed solidification in the regions bounding the letters D, O and E was achieved. The through thickness existence of the equiaxed grain structure outlinin...

Preliminary research has demonstrated the ability to utilise novel scan strategies in the electron beam melting (EBM) process to establish control of crystallographic texture within Inconel 718 deposits. Conventional EBM scan strategies and process parameters yield coarse columnar grains aligned parallel to the build direction. Through varying process parameters such as beam power, beam velocity, beam focus and scan strategy, the behaviour of the electron beam can be manipulated from a line source to a point source. The net effect of these variations is that the resulting crystallographic texture is controlled in a manner to produce either epitaxial deposits or fully equiaxed deposits. This research demonstrates the ability to change the crystallographic texture on the macroscale indicating that EBM technology can be used to create complex geometric components with both site-specific microstructures and material properties.

Relationships between electron beam parameters (beam current, beam speed, and beam focus) and physical properties (mass, diameter, elastic modulus, and yield strength) have been investigated for Inconel 625 mesh cubes fabricated using an additive manufacturing technology based on electron beam melting. The elastic modulus and yield strength of the mesh cubes have been systematically varied by approximately a factor of ten by changing the electron beam parameters. Simple models have been used to understand these relationships. Structural anisotropies of the mesh associated with the layered build architecture have been observed and may contribute, along with microstructural anisotropies, to the anisotropic mechanical properties of the mesh. Knowledge of this kind is likely applicable to other metal and alloy systems and is essential to rapidly realize the full potential of this burgeoning technology.

Additive manufacturing technologies, also known as 3D printing, have demonstrated the potential to fabricate complex geometrical components, but the resulting microstructures and mechanical properties of these materials are not well understood due to unique and complex thermal cycles observed during processing. The electron beam melting (EBM) process is unique because the powder bed temperature can be elevated and maintained at temperatures over 1000 °C for the duration of the process. This results in three specific stages of microstructural phase evolution: (a) rapid cool down from the melting temperature to the process temperature, (b) extended hold at the process temperature, and (c) slow cool down to the room temperature. In this work, the mechanisms for reported microstructural differences in EBM are rationalized for Inconel 718 based on measured thermal cycles, preliminary thermal modeling, and computational thermodynamics models. The relationship between processing parameters, solidification microstructure, interdendritic segregation, and phase precipitation (δ, γ′, and γ″) are discussed.

This study describes the seasonal distribution of larvae, nymph, and adult life stages for 3 species of ixodid ticks collected by tick drag and sweep methods from various habitats in the Republic of Korea (ROK). Grasses less than 0.5 m in height, including herbaceous and crawling vegetation, and deciduous, conifer, and mixed forests with abundant leaf/needle litter were surveyed at United States (US) and ROK operated military training sites and privately owned lands near the demilitarized zone from April-October, 2004 and 2005. Haemaphysalis longicornis Neumann adults and nymphs were more frequently collected from April-August, while those of Haemaphysalis flava Neumann and Ixodes nipponensis Kitaoka and Saito were collected more frequently from April-July and again during October. H. longicornis was the most frequently collected tick in grass habitats (98.9%), while H. flava was more frequently collected in deciduous (60.2%) and conifer (57.4%) forest habitats. While more H. flava (54.1%) were collected in mixed forest habitats than H. longicornis (35.2%), the differences were not significant. I. nipponensis was more frequently collected from conifer (mean 8.8) compared to deciduous (3.2) and mixed (2.4) forests.

Soldiers from the Republic of Korea and the United States conducting peacetime military operations at various training sites and multiple range complexes located near the demilitarized zone separating North and South Korea are exposed to rodents and their potentially disease-carrying ectoparasites. These diseases include scrub typhus, murine typhus, and leptospirosis. Many of the training sites are rural or semi-rural, surrounded or co-located with various forms of agriculture, and are infested with rodents and insectivores (as well as their ectoparasites), which are commonly found in association with unmanaged tall grasses, scrub, and crawling vegetation habitats. For 5 years, rodents and insectivores were collected seasonally (spring, summer, fall, and winter) at firing points 10 and 60 near the demilitarized zone and serologically tested for the presence of scrub typhus, murine typhus, and leptospirosis antibodies. Of the nine species of small mammals collected, Apodemus agrarius, the common striped field mouse and known reservoir of scrub typhus, was the most frequently collected (90.6%). Only four of the nine species captured, A. agrarius (60.9%), Micromys minutus (100%), Mus musculus (55.6%), and Rattus norvegicus (46.7%), were positive for scrub typhus. Of all the small mammals captured, only A. agrarius was positive for murine typhus (0.3%) and leptospirosis (1.3%). Seasonal and annual prevalence rates based on weight and sex are presented.

Soldiers from the Republic of Korea and the United States conduct armistice military operations at Twin Bridges Training Area (TBTA) located near the demilitarized zone (DMZ) and are exposed to zoonotic disease pathogens that small mammals and their potentially disease-carrying ectoparasites transmit. TBTA is a 36 km2 rural training site with small villages and various forms of agriculture along its boundary. At TBTA, rodents, insectivores, and their ectoparasites are commonly found in association with unmanaged habitats of various densities of tall grasses, herbaceous plants, shrubs, briars, and crawling vegetation. Rodents and insectivores were collected during the winter (November-December 2005 and December 2006) and early spring (March 2007), and serologically tested for the presence of scrub typhus, murine typhus, and leptospirosis antibodies. Of the six species of small mammals collected, Apodemus agrarius, the common striped field mouse and known reservoir of scrub typhus, was the most frequently collected (96.1%), followed by Crocidura lasiura (2.5%), Micromys minutus (0.5%), Myodes regulus (0.5%), Mus musculus (0.3%), and Rattus rattus (0.1%). A. agrarius (56.1%), M. musculus (66.7%), M. minutus (25%), and R. rattus (100%) were positive for scrub typhus antibodies. Only A. agrarius (14.7%) and C. lasiura (4.5%) were positive for murine typhus antibodies, whereas only A. agrarius (1.5%) was seropositive for leptospirosis. Seroprevalence rates of scrub typhus and murine typhus based on weight and sex of A. agrarius are presented.

The Twin Bridges Training Area (TBTA) in the Republic of Korea consists of dirt roads, barren training areas, and forested hillsides adjacent to linear and broad expanses of tall grasses, herbaceous, and scrub vegetation. Of the six species of small mammals, the striped field mouse, Apodemus agrarius, was the most frequently captured (96.1%). Apodemus agrarius capture rates varied from 17.7 to 33.2% during three trapping periods. Gravid females were observed during November-December 2006 (8.4%) and March 2007 (5.1%). In 2005, the overall seroprevalence of Hantaan virus (HTNV) was high (34.4%) and lower during surveys in 2006 (14.2%) and 2007 (13.8%). Seroprevalence was directly correlated with weight increase of A. agrarius.

Malaria was eradicated and the Republic of Korea (ROK) declared "malaria free" in 1979. However, in 1993, a temperate strain of vivax malaria, expressing both latent and nonlatent disease populations, re-emerged near the demilitarized zone (DMZ), rapidly spread to civilian sectors near the DMZ, and increased exponentially in ROK military, veteran, and civilian populations through 1998. Malaria among all ROK populations decreased 5-fold from a high of 4142 cases in 2000 to a low of 826 cases in 2004, before increasing again to 2180 cases by 2007. Each malaria case in the ROK is reported in the metropolitan area/province where the diagnosis is made, which may be at some distance from the area where infection occurred. Therefore, it is difficult to ascertain transmission sites since approximately 60% of vivax malaria in Korea is latent with symptoms occurring1 month to 24 months after infection. A review of case diagnosis for civilian, veteran, and military populations shows that nearly all malaria south of Gyeonggi and Gangwon Provinces is the result of veterans exposed in malaria high-risk areas along the DMZ and returning to their hometowns where they later develop malaria. Thus, malaria currently remains localized near the DMZ with limited transmission in provinces south of Seoul and has not spread throughout Korea as previously hypothesized. This report describes the reemergence of vivax malaria cases in civilian and military ROK populations and U.S. military personnel and assesses variables related to its transmission and geographic distribution.

Environmental geospatial data and adult and larval mosquito collection data for up to 106 sites throughout the Republic of Korea (ROK) were used to develop ecological niche models (ENMs) of the potential geographic distribution for eight anopheline species known to occur there. The areas predicted suitable for the Hyrcanus Group species were the most extensive for Anopheles sinensis Wiedemann, An. kleini Rueda, An. belenrae Rueda, and An. pullus Yamada, intermediate for An. sineroides Yamada, and the most restricted for An. lesteri Baisas and Hu and the non-Hyrcanus Group species An. koreicus Yamada and Watanabe and An. lindesayi Yamada. The relative vectorial importance of these species is unknown, and all, except An. koreicus and An. lindesayi, are predicted to occur widely in the northwest of the ROK where malaria transmission has been sporadic since its resurgence in 1993. Our ENMs suggest that it is unlikely that An. koreicus and An. lindesayi are vectors, but we do not document consistent geographic differentiation that might incriminate any of the other species as vectors. Because all species are predicted to occur in North Korea, we also cannot reject the hypothesis that malaria infected mosquitoes from North Korea may have been the cause of the resurgence of malaria in the ROK. Ecological differentiation of the eight species is inferred from collection locations and 34 environmental layers based on remote sensing and global climatic averages. Interspecific differences were noted, and characterizing mosquito habitats by ground-based and remote sensing methods is proposed.

Malaria is a significant health threat to U.S. combat forces that are deployed to malaria-endemic regions. From 1979, when the Republic of Korea (ROK) was declared malaria free, malaria did not present a health threat to U.S. forces deployed to Korea until the early 1990s. In 1993, a temperate strain of vivax malaria expressing both latent (long prepatent incubation periods of usually 6-18 months after infection) and nonlatent (short prepatent incubation periods30 days after infection) disease reemerged near the demilitarized zone (DMZ) and once again presented a primary health threat to U.S. military populations in the ROK. Following its reemergence, malaria rates increased dramatically through 1998 and accounted for44% of all malaria cases among U.S. Army soldiers from 1997 to 2002. More than 60% of all Korean-acquired malaria among U.S. soldiers was identified as latent malaria. Nearly 80% of all latent malaria attributed to exposure in Korea was diagnosed in the U.S. or other countries where soldiers were deployed. These data illustrate the requirement for a comprehensive malaria education program, especially for those soldiers residing or training in malaria high-risk areas, to inform soldiers and providers of the risk of developing malaria after leaving Korea.

Mosquito larval surveillance for environmental monitoring and pest-control purposes was conducted monthly at dredged soil-dumping areas during the construction of a new harbor in Yongcheon Bay, approximately 5 km SE of Jinhae, on the SW side of Namsan (Mt. Nam) and across the bay from Su-do (Su Island) in Gyeongsangnam Province, Republic of Korea (ROK) from November 2007 through April 2008. During this study, mosquitoes collected as overwintering larvae were Aedes togoi in brackish rock pools along the seashore and Anopheles lindesayi japonicus along the vegetated margins of a slow-flowing drainage ditch and associated freshwater ground pools containing green algae. Overwintering An. lindesayi larvae also were collected along stream margins and stream pools of moderate- to fast-flowing mountain streams near Chungju (Chungcheongbuk Province) (October 2007 and March 2008) and Munsan (Gyeonggi Province) (September 2007 and April 2008). First and second instars were collected and identified in late September 2007 through February 2008. During March and April, collections were primarily 3rd and 4th instars, and by the end of April, pupae were collected. This is the first report of An. lindesayi japonicus overwintering as larvae in the ROK.

Throughout Korea, small mammals are hosts to a number of disease-causing agents that pose a health threat to U.S. and Korean military forces while they conduct field-training exercises. A seasonal rodent-borne disease surveillance program was established at two firing points (FP), FP-10, and FP-60, and conducted over five years from 2001 through 2005 in response to hantavirus cases among U.S. soldiers. The ecology of these sites consisted primarily of tall grasses associated with semi-permanent and temporary water sources (drainage ditches and a small stream) and dry-land agriculture farming. Eight species of rodents and one species of insectivore were collected, including Apodemus agrarius, Micromys minutus, Mus musculus, Rattus norvegicus, Tscherskia triton, Microtus fortis, Myodes regulus, and Crocidura lasiura. The striped field mouse, A. agrarius, (primary reservoir for Hantaan virus, the causative agent of Korean hemorrhagic fever), was the most frequently collected, representing 90.6% of the 1,288 small mammals captured at both sites. Reported herein are the ecological parameters, seasonal population densities, and seasonal population characteristics associated with small mammals collected at two military training sites in the Republic of Korea.

Anopheles lindesayi japonicus Yamada is an uncommonly collected mosquito in Korea, and its presence is based upon limited collection data and anecdotal reports in Korean mosquito literature: 45 specimens collected from 15 identified sites. This study reports the collection of 538 specimens from 16 sites as part of the authors' 2004–2007 anopheline surveillance. Larvae were collected from stream margins, stream pools, rock pools, seepage springs, artificial containers, swamps, and ditches and were found in association with seven other culicid species. Inclusion of the authors' data with previous published and unpublished records makes this a comprehensive report on this species in Korea. New province records are reported for this species at Hwacheon and Wonju in Gangwon Province, Mt. Palgong in Daegu Metropolitan, and Chungju and Mt. Worak in Chungcheongbuk Province in the Republic of Korea.

Acute-phase sera from >5 % of cases of haemorrhagic fever with renal syndrome occurring annually in Korea have been found to exhibit a fourfold or higher antibody titre to Puumala virus (PUUV) than to Hantaan virus (HTNV) by double-sandwich IgM ELISA, suggesting the existence of a PUUV-related hantavirus. Based on the phylogenetic relationships among arvicolid rodents, the royal vole (Myodes regulus) was targeted as a likely reservoir host of hantavirus. Using RT-PCR, a genetically distinct hantavirus, designated Muju virus (MUJV), was detected in lung tissue of royal voles, captured in widely separated geographical regions in Korea during 1996–2007. Pairwise analysis of the full-length S (1857 nt) and M (3634 nt) segments of MUJV indicated approximately 77 % sequence similarity with PUUV. At the amino acid level, MUJV differed from PUUV by 5.5–6.9 % (nucleocapsid) and 10.0–11.6 % (Gn and Gc envelope glycoproteins). Interstrain variation of MUJV sequences from royal voles captured in different regions suggested geographic-specific clustering. Neutralizing antibody titres against PUUV were two- to sixfold higher than to HTNV in sera of MUJV-infectedMyodes regulus. Although virus isolation attempts were unsuccessful, the collective data indicate that MUJV is a distinct hantavirus species.

In 2005, adult and larval mosquito surveillance was conducted at selected sites in Korea to associate larval habitats with species distribution of mosquitoes of the Anopheles Hyrcanus Group (An. sinensis, An. lesteri, An. pullus, An. belenrae and An. kleini) and other mosquito species. Anopheles specimens belonging to the Anopheles Hyrcanus Group were identified to species level by molecular confirmation using the internal transcribed spacer (ITS)-2 within nuclear ribosomal (r)DNA. A total of 6644 mosquitoes from resting and light trap collections (4451; 67.0%) and larval collections (2193; 33.0%) comprising 32 species and nine genera (Culex [11], Anopheles [8], Ochlerotatus [5], Aedes [3], Armigeres [1], Coquillettidia [1], Mansonia [1], Tripteroides [1] and Lutzia [1]) were collected. Larval habitats were characterized into 14 categories. Of a total of 4534 Anopheles spp. collected (3766 resting and light trap collections and 768 larval collections), Anopheles sinensis (3194; 70.4%) was the most frequently captured, followed by An. kleini (813; 17.9%), An. pullus (299; 6.6%) and An. belenrae (129; 2.8%). Four species of Anopheles (An. lesteri, An. sineroides, An. koreicus and An. lindesayi) were infrequently collected (

In this project, Avure and ORNL evaluated the influence of hot isostatic pressing (HIP) and thermal cycling as standalone post processing techniques on the microstructure of electron beam powder bed deposited Ti-6Al-4V and Inconel 718 alloys. Electron beam powder bed deposition is an effective technology for fabricating complex net shape components that cannot be manufactured with conventional processes. However, material deposited by this technology results in columnar grain growth which is detrimental for many applications. For Ti-6Al-4V, it has been found that thermal cycling alone is not sufficient to breakdown the columnar microstructure that is typical of electron beam powder bed technology. HIP, on the other hand, has the potential to be an effective technique to break down the columnar microstructure of Ti-6Al-4V into a more equiaxed and refined β grain structure, and provide a more homogeneous microstructure compared to the thermally cycled samples. Overall, the project showed that hot isostatic pressing reduced/eliminated porosity in both Ti-6Al-4V and Inconel 718 However, based on the unique thermal cycle and the application of pressure in the HIP vessel, Ti-6Al-4V e-beam deposited microstructures were modified from columnar grain growth to equiaxed microstructures; a significant outcome to this collaboration. Inconel 718, on the othermore » hand, shows no change in the macrostructure as a result of the current HIP cycle based on the thermal history, and would require further investigation. Though the results of HIP cycle were very good at changing the microstructure, further development in optimizing the post heat treatments and HIP cycles is required to improve mechanical properties.« less

As part of the 65th Medical Brigade tick-borne disease surveillance program to determine the abundance, geographical and seasonal distributions, and tick-borne pathogens present in the Republic of Korea, dragging and sweeping methods were compared to determine their efficiency for collecting ticks in grass and deciduous, conifer, and mixed forest habitats at military training sites and privately owned lands in northern Gyeonggi Province near the demilitarized zone from April-October, 2004-2005. Three species of Ixodid ticks, Haemaphysalis longicornis, Haemaphysalis flava, and Ixodes nipponensis, were collected. Overall, H. longicornis adults and nymphs were most frequently collected from grass and deciduous forest habitats, accounting for 98.2 and 66.2%, respectively, of all ticks collected. H. flava adults and nymphs were most frequently collected from conifer and mixed forests, accounting for 81.6, and 77.8%, respectively, of all ticks collected. I. nipponensis adults and nymphs accounted for 9.3% of all ticks collected from mixed forests, were less commonly collected from deciduous (4.1%) and conifer (4.1%) forests, and infrequently collected from grass habitats (0.9%). Overall, there were no significant differences between dragging and sweeping methods for the three species when the areas sampled were similar (sweeping = 2 x the area over the same transect). Adults and nymphs of H. longicornis were most commonly collected from April-August, while those of H. flava and I. nipponensis were most commonly collected during April-July and again during October. Larvae of all three species were most frequently observed from July-September.

We used epidemiological data and indirect fluorescent antibody tests to determine the Hantaan virus (HTNV) antibody-positive (Ab+) prevalence in small mammals captured at firing point 10 (FP-10) and firing point 60 (FP-60), Gyeonggi Province, near the demilitarized zone, Republic of Korea (ROK), from 2001 to 2005. We used these data, combined with the partial M segment amplified from HTNV recovered from lung tissues of Apodemus agrarius, to clarify the genetic diversity and phylogenetic relationships among HTNV strains in the ROK. Of the eight species of rodents and one insectivore species captured, A. agrarius accounted for 93.4% and 88.5% at FP-10 and FP-60, respectively. Only two species of rodents, A. agrarius and Micromys minutus, were HTNV Ab+. The overall HTNV Ab+ prevalence for A. agrarius captured at FP-10 and FP-60 was 23.3% (121/520) and 14.5% (94/647), respectively. The hantaviral reverse transcription-polymerase chain reaction-positive rate of Ab+ A. agrarius was 74.2% (167/215), and the phylogenetic trees, based on the 269-nucleotide G2-encoding M segment, demonstrated that HTNV strains from FP-10 and FP-60 were distantly segregated from HTNV of other geographic regions in Korea and China. These data are useful in the development of risk reduction strategies for the prevention of hantavirus infections among military personnel, especially during training or the event of hostilities, and civilian populations.

A total of 180 larval collection sites (e.g., rice paddies, marshes, ground pools, ponds, stream margins, and irrigation and drainage ditches) was surveyed within a 2 km radius from Warrior Base training area, 5 km south of Panmunjeom (Joint Security Area, demilitarized zone), Gyeonggi Province, Republic of Korea (ROK), from May through October, 2007 to characterize larval habitat distributions of members of the Anopheles Hyrcanus Group (An. sinensis, An. lesteri, An. pullus, An. belenrae, An. kleini, and An. sineroides). A total of 5,859 anopheline larvae was collected from 84.4% of the sites surveyed, of which 4,071 were identified to species by polymerase chain reaction (PCR) using the ribosomal DNA internal transcribed spacer 2 (rDNA ITS2). Anopheles sinensis (52.6%) was the most frequently collected, followed by An. kleini (29.4%), An. sineroides (9.8%), An. pullus (6.7%), An. belenrae (1.1%), and An. lesteri (0.5%). Anopheles pullus and An. kleini were collected in greater proportions in May and from May - July, respectively. Few An. sinensis were collected from May - June, but it was the predominant species collected by August, and accounted for80% of all larvae from September - October. Anopheles kleini was found in all habitats sampled; however, it was collected most frequently in young growth rice paddies, while An. sinensis was collected more frequently in mature and post-harvest paddies. Anopheles pullus was associated with pre-cultivated rice paddies, including water-filled tire ruts left from the previous fall's harvest.

Fleas were collected from live-captured small mammals to identify flea-borne pathogens, host associations, and seasonal prevalence of flea species, as part of the 65th Medical Brigade rodent-borne disease surveillance program at 20 military installations and training sites, Gyeonggi Province, Republic of Korea, 2005-2007. A total of 1251 fleas were recovered from 2833 small mammals. Apodemus agrarius, the striped field mouse, accounted for 93.1% (2,637/2,833) of all small mammals captured, followed by Crocidura lasiura (3.1%), Mus musculus (1.3%), Microtus fortis (0.7%), Myodes regulus (0.7%), Micromys minutus (0.5%), Rattus norvegicus (0.4%), Tscherskia triton (0.1%), Apodemus peninsulae (0.1%), Rattus rattus (0.1%), and Mogera robusta (0.1%). A total of 6/11 species of mammals captured were infested with fleas with infestation rates ranging from a high of 26.3% (A. agrarius and M. regulus) to a low of 5.3% (M. fortis). Flea indices among infested mammals were highest for R. norvegicus (2.50), followed by C. lasiura (2.20), A. agrarius (1.71), M. regulus (1.20), M. musculus (1.0), and M. fortis (1.0). The predominant flea species collected were Stenoponia sidimi (56.5%), followed by Ctenophthalmus congeneroides (38.3%) and Rhadinopsylla insolita (3.9%). The minimum field infection rates [number of positive pools/total number of fleas (600)] for Rickettsia typhi and for Rickettsia felis were 1.7% and 1.0%, respectively.

Beginning in January 2002 and ending in November 2003, data were collected on the size (eggs/egg raft) and occurrence of egg rafts laid by Culiseta incidens within 5 miles of Fort Lewis, WA. Culiseta incidens initiated oviposition in late March to early April and ceased oviposition in September-October. Twenty egg rafts from Culex pipiens, a larval habitat associate of Cs. incidens, were also collected during this study and that information is reported. Culex pipiens initiated oviposition in late May, and termination of oviposition appeared to occur in late August. The range of the number of eggs per raft was 59-329 for Cs. inicidens and 218-413 for Cx. pipiens.

A limited survey was conducted in 2003 to determine if Ochlerotatus japonicus was spreading outside of King County, Washington. Ochlerotatus japonicus was found in north-central Pierce County and west-central Snohomish County. These collections represent county records. An additional site was reported from King County. Ochlerotatus japonicus is established and spreading to other areas of Washington.

Before this study, the mosquito Ochlerotatus (Finlaya) togoi (Theobald) had been reported from only 2 locations within the continental United States, both of which were documented in Washington State. This study used active and passive surveillance to determine the current distribution of Oc. togoi along the Pacific Coast of Washington. Results of the study show that small, but stable, populations of Oc. togoi exist in the northern San Juan Island region of Puget Sound. Geological formations in this region are conducive to rock holes and support populations of Oc. togoi. No members of Oc. togoi were found on the southwestern Washington coast, the coast of the Olympic Peninsula, or in the lower Puget Sound.

This is a report on the 1st occurrence of Ochlerotatus japonicus in the state of Washington. In August through November 2001, immature stages were found near the King County communities of Carnation (2 sites), Black Diamond, Kent, and Issaquah and were reared to the adult stage for identification and preservation.

In May 2000, a dead porcupine (Erethizon dorsatum Culiver) was found on an infrequently traveled dirt road at Camp Ripley, MN. The presence of late instar Calliphoridae suggested that the porcupine died within the past 4 to 7 d. Adult carrion (Silphidae) and rove (Staphylinidae) beetles were observed under the carcass. In June, a large number of adult American dog ticks, Dermacentor variabilis (Say), were observed questing on the porcupine and the surrounding grass. Six zones were established around the carcass, and each zone was sampled for ticks once a month from June through September. Ticks were captured in June and July, and 93% were captured within 2 m of the carcass. Gases released as part of the decomposition process were believed to attract the ticks to the carcass.

This book is primarily a mosquito identification manual (70 of its pages) and follows dichotomous couplet formatting, which is common to insect identification keys and should be familiar to the boo...

From April 2008 through May 2009, ticks were collected from domestic, stray, and military working dogs when they were examined at any of the four US Army veterinary treatment facilities within the Republic of Korea. Approximately 2,500 dogs were examined during this period, and a total of 411 ticks (125 larvae, 200 nymphs, 67 females, 19 males) were collected from 18 dogs. The collected species were Haemaphysalis longicornis (6F, 195N), Haemaphysalis flava (19M, 52F), Ixodes nipponensis (7F), and Rhipicephalus sanguineus (2F). Five nymphs and all larvae were identified to genus only. Military working dogs received routine veterinary care, including preventive ectoparasite treatments, and were found to be free of ticks.

A total of 4,575 ticks were collected from 5,953 small mammals captured from March 2004 to December 2008 at 19 military training areas and 6 US military installations, Gyeonggi and Gangwon Provinces, Republic of Korea. Ixodes nipponensis (98.9%; 753 nymphs, 3,771 larvae) was the most frequently collected tick, found on six of the 11 small mammal species captured, followed by Ixodes pomerantzevi (1.1%; 17 females, 9 nymphs, 24 larvae) found on two species. While only one T. sibiricus was collected, it was infested with 44 ticks, with an infestation rate of 100.0%, followed by Rattus norvegicus (16.7%, n=18), Apodemus agrarius (14.6%, n=5,397), Crocidura lasiura (7.5%, n=265), Microtus fortis (7.3%, n=82), Myodes regulus (5.7%, n=53), and Micromys minutus (4.8%, n=63). No ticks were collected from Apodemus peninsulae (n=3), Mus musculus (n=58), Tscherskia triton (n=12), and Mogera wogura (n=1). Ixodes nipponensis nymphs were most frequently collected from small mammals from March to April, while larvae were more frequently collected during September. Ixodes pomerantzevi was collected only during February-April 2008, and a single Haemaphysalis flava nymph was collected from A. agrarius in August 2004.

The prevalence of tick-borne encephalitis virus (TBEV) in southern Korea was determined by collecting ticks using tick drags. A total of 4,077 of 6,788 ticks collected were pooled (649 pools) according to collection site, species, and developmental stage and assayed for TBEV. The TBEV protein E and NS5 gene fragments were detected using RT-nested PCR in six pools of nymphs collected from Jeju Island (2,491 ticks). The minimum field detection rates for TBEV were 0.17% and 0.14% for Haemaphysalis longicornis and Haemayphysalis. flava nymphs, respectively. The 252 bp NS5 and 477 bp protein E gene amplicons were sequenced. Phylogenetic analysis showed that the NS5 and protein E genes of the Jeju strain were clustered with Western subtype (98.0% and 99.4% identity, respectively). The Western subtype of TBEV is endemic in Korea, including Jeju Island. The study of vector and zoonotic host susceptibility to TBEV is required to better understand its potential impact on public health.

During 2008, small mammals were captured and examined for ticks at Chipori (Gangwon Province) and Nightmare (Gyeonggi Province) Ranges near the Demilitarized Zone, Republic of Korea (ROK). Ixodes nipponensis Kitaoka and Saito (75 nymphs, 835 larvae) was collected from Apodemus agrarius (Pallas), Micromys minutus (Pallas), and Crocidura lasiura Dobson, while Ixodes pomeranzevi Serdyukova (2 females, 4 nymphs) was collected only from A. agrarius. Separately, I. pomeranzevi (15 females, 5 nymphs, 24 larvae) was collected from Tamias sibiricus (Laxmann) near Bidulginang Falls (Gyeonggi Province). This is the first record of I. pomeranzevi from Apodemus agrarius in the ROK.

In 2008, tick surveillance of migratory birds was conducted on Hong-do (Hong Island), Jeollanam Province, Republic of Korea. Seventy-seven ticks representing two genera and four species—Haemaphysalis flava Neumann (21 ticks), Haemaphysalis ornithophila Hoogstraal & Kohls (2), Ixodes nipponensis Kitaoka & Saito (3), and Ixodes turdus Nakatsuji (51)—were collected from 12 species of birds belonging to nine genera. Two male H. ornithophila, an uncommonly collected tick, were removed from a scaly thrush, Zoothera dauma (Latham), on Hong-do. Haemaphysalis ornithophila is a Southeast Asian species that was transported to Korea during the spring migration of Z. dauma to its breeding grounds in Russia. This first report of H. ornithophila from Korea has implications for the introduction of exotic tick species and their pathogens on migratory birds.

Tick surveys were conducted during April 2007 in Jeju Province and along the southern coast of Gyeongsangnam and Jeollanam Provinces, Republic of Korea, to assess tick species composition and distribution, and to study tick habitat associations. A total of 58, 19, and 25 sites were surveyed in Jeju, Gyeongsangnam, and Jeollanam Provinces, respectively. Surveys were conducted using tick drags through various vegetative habitats. Habitat descriptions were recorded for each 10-m drag and analyzed to determine habitat associations for each collected species. During this survey, Haemaphysalis (Ornithophysalis) phasiana Saito, Hoogstraal and Wassef was collected at 10 sites (144 nymphs) in Jeju Province and at six sites (70 nymphs and 2 females) in Jeollanam Province (new records for both provinces), but was not collected at the 19 survey sites in Gyeongsangnam Province. Haemaphysalis phasiana was collected at elevations of 5‐245 m and in or near areas that had a marked presence of pine trees as well as dry or green grasses, other herbaceous vegetation, and deciduous understory.