Resting Places Of Adult Black Flies In The Upper Reaches Of The Ukawa River, Japan And Identification Of Flight Direction Of Black Flies Using Sticky Traps

To exterminate and control adult black flies in the upper reaches of the Ukawa River, we selected 10 sites in the Betsumata Area where the density of black flies fly is relatively high, and examined the flight direction of adult black flies using directional sticky traps with an improved flight interception trap. The survey was conducted three times, on July 1-2, August 26-27, and October 8-9, 2023. On the survey days in both July and August, no strong winds or bad weather conditions were observed during the investigation time. In July, a total of 955 individuals were captured at 10 sites, with 8 directions, and at 10 sites/day. At the Tashiro site, where the largest number of flies was caught, a total of 255 individuals/day were captured on 8 surfaces. A total of 1,083 individuals were captured in the August survey, and a total of 266 individuals/8 directions/day of adult black flies were captured at the Sekitoki site. More than 90% of the adult black flies were Simulium (Simulium) arakawae, and many black flies were oriented in the direction of rivers and small waterways. In addition, a small number of black flies were oriented at all points in the direction of paddy fields, suggesting that they did not fly from the paddy fields.