Search

Movement of adult An. minimus Theobald between larval habitats and feeding sites was investigated by mark-release-recapture in March 1993 on Ishigaki Island, Ryukyu Archipelago, Japan. Unfed (998 females) and fed (1,485 females) cohorts from a laboratory colony were marked with different colors of fluorescent dye, and released near Nishihama stream where larvae were abundant. Overall, 42 fed (2.82%) and 13 unfed (1.30%) females were recaptured. Among these, 12 females were recaptured at a cowshed, the nearest blood meal source. Most females in the fed cohort recaptured at the release point had developing or matured ovaries, whereas 55% at the cowshed were parous. The movement of released females from larval habitat to the cowshed for blood feeding indicated a flight distance >1 km.

In 1991–1993, the density (numbers per 10 dips) and abundance (density × flooded area) of mosquitoes were studied in 3 areas of northern Thailand with different environmental conditions. Culex tritaeniorhynchus Giles, Cx. vishnui Theobald, and Cx. gelidus Theobald were predominant among the 8 Culex species collected. Abundance of these 3 species varied significantly among the 3 areas. Type of habitat classified according to agricultural practices in rainy and dry season significantly influenced larval abundance of Cx. tritaeniorhynchus and Cx. vishnui. Seasonal variation in larval abundance was significant only in Cx. vishnui. The response of the 3 vector mosquitoes to environmental heterogeneity is discussed.