2005. Proceedings of the Indiana Academy of Science 1 14(l):62-64

DISCOVERY OF AN EXOTIC ASIAN , OCHLEROTATUS JAPONICUS, (DIPTERA: CULICIDAE) IN SOUTHERN INDIANA

Steven P. Moberly, Craig Lalor and Mollie McDonough: School of Natural Sciences, Indiana University Southeast, New Albany, Indiana 47150 USA

Brad Foster and Adam Estes: Indiana State Department of Health, 635 North Barnhill Drive, Indianapolis, Indiana 46202 USA

Douglas J. Bentfield: Clark County Health Department, 1320 Duncan Ave., Jeffersonville, Indiana 47130 USA

ABSTRACT. Ochlerotatus (Oc.) japonicus, an exotic Asian mosquito, appeared in New York, New Jersey and Connecticut in 1998. The species now inhabits 20 eastern states, Washington state and Quebec, Canada. Oc. japonicus was found at three sites near an existing railway system in Clark County, southern Indiana, in July 2004. During the 2004 sampling season, the species was found in small numbers at 20 of 100 sampling locations in Clark, Floyd and Harrison counties. Most early samples were taken near existing railway and interstate transportation systems. Later, in September and October, the mosquito expanded its range into other habitats. This invading non-indigenous species should be monitored closely since it is a known vector for several viral pathogens including those responsible for , , and eastern equine encephalitis.

Keywords: Ochlerotatus japonicus, Indiana, Diptera, Culicidae

Ochlerotatus (Oc.) japonicus, the Asian may have arrived in Texas in a shipment of rock pool mosquito, is an exotic species that used tires and then spread across southeastern was introduced into the United States in 1998, USA along the interstate highway system possibly in shipments of used tires entering (Moore & Mitchell 1997). albopictus New York, New Jersey and Connecticut (Pey- currently is very common in many southern ton et al. 1999). Since the initial discoveries, states. Ochlerotatus japonicus could be mov- the mosquito has been quickly expanding its ing westward in a similar fashion, hitching a range (Fonseca et al. 2001). By the end of ride in tires and other containers found on

2003, it was found in Quebec, Canada and 19 barges, trains and trucks. Alternatively, the states: Connecticut, Delaware, Georgia, species may have had a more direct transit via Maine, Massachusetts, Maryland, North Car- airline, train or truck traffic from the west olina, New Hampshire, New Jersey, New coast. York, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, Vermont, RESULTS Washington and West Virginia (Scott 2004). We report the first Indiana appearance of

It is almost certain that the Ohio specimens Ochlerototus (Oc.) japonicus in Clark County, found in 1999 came from New York or New southern Indiana. In July 2004, the first spec- Jersey since they were trapped near a tire re- imens of Oc. japonicus appeared in mosquito treading business that regularly receives ship- nets set by Indiana University Southeast re- ments from the east coast (Berry 1999). searchers. We suspected the mosquito was a Since Ochlerotatus japonicus has a short new species for Indiana and forwarded the un- llight range of less than 1.6 km, its rapid identified specimens to the Indiana State De- movement into several states presumably was partment of Health where Brad Foster and facilitated by interstate trade and transit (Fon- Adam Estes verified the identification. In Au- seca et al. 2001 ). Studies have shown that an- gust 2004, Dina Fonseca of the Smithsonian other Asian mosquito, Aecies (Ae.) albopictus. Institution further substantiated the identifi-

62 MOBERLY ET AL.—EXOTIC ASIAN MOSQUITO rr< cation using mitochondrial DNA-sequencing arrived with Aedes albopictus via movement techniques. of goods along interstate and water transpor- The first Indiana specimens were trapped in tation routes. To adequately assess the num- early July 2004 in both urban and rural areas bers of Oc. japonicus in Indiana, sampling ef- of Clark County, very near an existing active forts should include collections of larvae from railway. In the immediate vicinity of the trap natural habitats where the species is known to locations, we found water-filled artificial con- lay its eggs (rock pools, tree holes, and spring- tainers, small drainage systems with pooled fed depressions). water and older trees with tree holes. These Travel and the rapid transcontinental move- locations correspond well with published hab- ment of products are known to be potent forc- itat data from New Jersey, Connecticut and es in the emergence of disease (Wilson 1995). New York (Andreadis et al. 2001). Nets in Invading non-indigenous species can cause which Oc. japonicus were found typically public health problems, and the number of in- contained specimens of Culex pipiens and Ae- troductions is expected to rise (Fonseca 2001 I. des albopictus. In addition to being found in used tires. Ae. After the initial finding, we established albopictus and Oc. japonicus have also been base-line information at our sampling loca- found in a variety of other materials: Luck) tions so that we can follow the distribution Bamboo (an ornamental lily in the genus Dra- and numbers in subsequent years. Briefly, dur- caena), imported machinery, and in airplanes ing sampling from May-October 2004, we (Linthicum et al. 2003). found 48 Oc. japonicus in about 20,000 mos- Ochlerotatus japonicus is important from a quito specimens at 20 of 100 sampling loca- public health perspective because it can tions. We also found the species at one loca- spread the pathogens responsible for West tion in Salem, Indiana (Washington County). Nile virus, St. Louis encephalitis, eastern Of these 21 locations, 15 were less than 0.4 equine encephalitis, and Japanese encephalitis km from the railway system. As the sampling (Sardelis & Turrell 2001; Sardelis et al. 2002: season progressed, specimens were found in Sardelis et al. 2003; Takashima & Rosen more traditional settings near failing septic 1989; Turrell et al. 2001). In Japan, the mos- systems (2 stations), the interstate highway quito sometimes bites humans who venture system (2 stations), arboreal settings (1 sta- into forested habitats (Peyton et al. 1999). In tion) and a tire dump (1 station). Connecticut in wooded habitats. Andreadis et al. (2001) found that human bait enhanced b\ DISCUSSION CO, attracted Oc. japonicus. This suggests The failure to detect Ochlerotatus japonicus that the species will feed on humans. in Indiana in previous sampling seasons may Unlike many other mosquitoes (e.g.. Ac. al- be related to the low capture frequency of this bopictus and Ae. aegyptii), Oc. japonicus species using traditional light and gravid trap readily inhabits areas such as Hokkaido. Japan methods. Andreadis et al. (2001) found Oc. where winter temperatures drop below IS japonicus in 0.5% of 182,590 adult female °C. (Fonseca et al. 2001). With its abilitx to mosquitoes taken in 1999 and 2000. In these survive very cold winters, we expect Oc. ja- samples, the light and gravid traps produced ponicus to spread throughout most of the less than 2.5 mosquitoes per trap. northern United States and Canada.

Our results compare favorably with those The discovery oi' Oc. japonicus in southern published by Andreadis et al. (2001). We Indiana verifies the importance o\ existing found the new mosquito in 0.25% of 20,000 mosquito control and monitoring programs. mosquitoes with a capture rate of 1-3 mos- The selection oi' natural predators and com- quitoes per trap. Once our finding was publi- petitors, elimination of mosquito habitat, and cized and other researchers developed search regulation oi' on trade vessels are a tew images for this species, other counties began v>( the many actions being taken to slow the to report its occurrence. Therefore, it is tempt- introduction oi~ foreign species. On a local lev- ing to conclude that the mosquito may have el, public awareness and education are ke\ been present for some time and is now being factors; however, research into the spread of detected because researchers are searching for these vectors is o\' equal importance. Toda) 's the organism. In fact, the mosquito could have unprecedented swift transit of goods has set .

64 PROCEEDINGS OF THE INDIANA ACADEMY OF SCIENCE the stage for the spread and emergence of ad- American Mosquito Control Association 19(4): 301-308. ditional infectious diseases. It is essential, Moore. C.G. C.J. Mitchell. 1997. Aedes albop- therefore, to research how these mosquitoes & ictus in the United States: Ten-year presence and disperse and take action to protect our local public health implications. Emerging Infectious environments. Diseases 2(3):329-334. ACKNOWLEDGMENTS Peyton, E.L., S.R. Campbell. T.M. Candeletti. M. Romanowski & W.J. Crans. 1999. Aedes (Fin- The Clark, Floyd and Harrison County In- laya) japonicus japonicus (Theobald), a new in- diana Health Departments and Indiana Uni- troduction to the United States. Journal of the versity Southeast provided funding for this American Mosquito Control Association 15(2): project. Dr. Claude Baker, Professor of Biol- 238-241. ogy at Indiana University Southeast served as Sardelis, M.R & M.J. Turell. 2001. Ochlerotatus j. project director and mentor. His help is grate- japonicus in Frederick County, Maryland: Dis- fully acknowledged. We also acknowledge Dr. covery, distribution, and vector competence for Dina M. Fonseca of the Smithsonian Institu- . Journal of the American Mos- 137-141 tion and the Academy of Natural Sciences quito Control Association 17(2): Sardelis. M.R.. D.J. Dohm, B. Pagae, B. Andre & who verified the specimens using DNA-se- M.J. Turrell. 2002. Experimental transmission quencing techniques. of eastern equine encephalitis virus by Ochlero-

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