Abstract
A survey was carried out during 1998-1999 to determine the distribution and seasonal abundance of An. minimus Theobald in Ishigaki Island, Ryukyu Archipelago, Japan. Larvae and pupae of An. minimus were collected in 33 of 48 streams in 1998, and 38 of 56 streams in 1999. Immatures of An. minimus were found in almost all the surveyed streams except those in urban areas, fast flowing streams and polluted streams. The abundance of immatures in Fanan and Nishihama Streams, where a lot of the immatures was collected, showed seasonal variation which was positively correlated with water temperature and rainfall. Few immatures were collected during winter season (December to February). As the temperature started to rise in March, the population increased and the density became high from May to August, and October to November, 1999. In Arakawa Stream near urban area, unlike Fanan and Nishihama Streams, the population of An. minimus immatures became biggest from March to April. By light trap method, more than 30 An. minimus adults per night were collected from March to November except May, and the highest number was 228 in July and 321 per night in November, 1999, near Nishihama Stream.
