Around Lake Suwa, Nagano Prefecture, the massive flights of chironomid midges have occurred frequently, and caused a nuisance problem for neighboring residents, business activities and tourism. In order to control adult midges, we studied the time of flight and dispersal range (vertical) of chironomid midges at the Research and Education Center for Inlandwater Environment, Shinshu University from April 18 to 20 and June 5 to 7, 1989, June 5 to 6, 1999, and September 4 to 6, 2000. Light traps were set at different heights (i.e., 1m, 9m and 16m roof).
Chironomus plumosus midges were trapped most at height of 16m at any time. On the other hand,
Chironomus dissidens were largely trapped at height of 9m. The time of flight was checked every 2hr during the investigation periods. In the case of
C. plumosus, the flight activity reached the peak at 18:00-20:00 in spring and fall, while 18:00-6:00 in summer. In the case of
C. dissidens, the peak was from 18:00 to 20:00 during the emergence periods. It was concluded that the vertical flight range were different among species and the flight time of
C. plumosus showed a seasonal variation.
View full abstract