Seasonal distribution and habitat selection by Aedes albopictus and Ae. riversi (Diptera: Culicidae) in northern Kyushu, Japan.

Temporal and spatial distribution of adult and larval Aedes albopictus (Skuse) and Aedes riversi Bohart & Ingram were studied on a small island and coastal area of northern Kyushu, Japan. Adults of Ae. albopictus attracted to human bait were distributed uniformly in an evergreen forest, a citrus orchard surrounded by forest, and an area disturbed by humans, whereas Ae. riversi was confined to evergreen forest and its adjacent area. Adults of both species occurred from May through October. Although Ae. riversi outnumbered Ae. albopictus early in the season, Ae. albopictus were much more abundant than Ae. riversi later in the season, with maximum abundance in July-September. Larval Ae. riversi occurred primarily in tree holes but also were found in bamboo stumps and artificial containers in forests. Despite the abundance of adult Ae. albopictus in the forest, larvae occurred in tree holes less frequently than Ae. riversi; it more frequently exploited bamboo stumps, stone vases, and discarded tires outside the forest.