The mosquito fauna of Rota Island, Mariana Islands (Diptera: Culicidae).

A mosquito survey on Rota Island was made during 9-16 May 1976. A variety of natural habitats was sampled and both larval and adult collections were made. A total of 7 species was captured. Three of these were new records for the island and they indicated intra-Mariana Islands distribution. Mosquito-borne diseases and vector species are reviewed for Rota and the other southern Mariana Islands. The collection data are presented and analyzed. U.S. Navy entomologists made a mosquito survey on the island of Kota in the fall of 1945. A total of 6 species was recovered and 2 of them, Aedes rotanus 13ohart & Ingram and Culex litoralis 13ohart, were described as new. According to the literature, this was the only documented survey of the mosquito fauna of Kota. The data for the October 1945 survey of Kota were included initially by Bobart & Ingram (1946) and in greater detail by 13ohart (1957) in their comprehensive r views of the mosquitoes of the Marianas. These species, with collection information, are listed in the Appendix. Mosquitoes have been linked with disease transmission in the Marianas. The principal mosquitoborne diseases have been dengue fever, a rather benign type of filariasis, Japanese 13 encephalitis, and malaria. Only dengue fever has been reported from Kota. However, the occurrence of the other diseases on nearby islands indicates the possibility of local epidemics. There have been several recorded outbreaks of dengue fever in Micronesia and 3 cases were reported from Kota in 1935 (Sogen 1941). An epidemic of dengue fever occurred on the neighboring islands of Tin]an, Saipan, and Guam during 1944 (13ohart & Ingram 1946). Filariasis in Guam has been reported (Kindleberger 1912). There was a major epidemic of Japanese 13 encephalitis on Guam during November 1947January 1948 (Hammon et al. 1958), and 2 separate outbreaks of malaria occurred on Guam in 1966 and 1969 (Hayes & Whitworth 1970). Kota is one of the southernmost islands of the Mariana chain, being located about midway between Guam and Saipan. The island is roughly rectang'ular with a prominent peninsula at its views expressed herein are those of the authors and do not necessarily reflect the views of the United States Air Force or the Department of Defense. 2Entomology Services, HQ 1st Medical Service Wing (PACAF), APO San Francisco 96274, U.S.A. southwest corner. It is 19.8 km at its longest axis, averages 6.3 km in width, and is the highest of the southern Marianas. Gressitt (1954: 53) describes Kota as consisting of a series of 5 or more elevated coral limestone terraces, largely sloping seaward, and rising to 496 m just southwest of the center. The eastern 1/2 is a wide plateau and there are precipitous limestone cliffs along the southern perimeter. The western 1/2 of the island is dominated by Mt Gressitt (1954) gives the height of the island as 496m, but Chart N.O. 81063 (Kota) published by the U.S. Naval Oceanographic Office in Washington, D.C. in June 1969 and revised in 1973 shows a maximum altitude of 491 m. The population center, Songsong Village, is at the west end of the wide bay on the southern coast. Fresh water flows from an artesian source in a cave high up on the southern limestone cliff. MATERIALS AND METHODS The island was divided into 7 survey zones, and 1 full day was devoted to sampling mosquitoes in each zone. Collecting methods included the examination of both natural habitats and artificial containers for immature forms, employment of portable light traps, and operation of human bait stations. Particular survey attention was given to the 4 major areas of vector contact or breeding on the island: the airport, Songsong Village, public beaches, and the refuse dump. Totals of 1174 adult and 131 immature mosquitoes were identified. The collection zones and sampling points are shown in 1, and the zones are described below. Zone I: This began at Songsong Village and included the narrow western coastline northward to Tatqua Pt. This area is characterized by a narrow beach and littoral on one side and a swath of heavy brush cover to the base of Mt Sabana on the opposite side. This survey area included the refuse dump. Zones H & III: The eastern end of the island comprised these 2 zones. This relatively level plain measures 5 km north to south and 8 km east to west and has an average elevation of 160 m. It grades Igently into the sea along the northern shore but is steep along its southern coastline. The Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 24 DEC 1977 2. REPORT TYPE 3. DATES COVERED 00-00-1977 to 00-00-1977 4. TITLE AND SUBTITLE The Mosquito Fauna of Rota Island, Mariana Islands (Diptera: Culicidae) 5a. CONTRACT NUMBER