Abstract
The effectiveness of mechanical removal of substrates for the control of benthic chironomid midge populations in a concrete-lined flood control channel system (draining domestic and industrial waste water and storm water) was studied. Substrates from a 0.80 km long section of one of the channels were mechanically removed. Fine sand and detritus were the 2 predominant types of substrates in the area cleared. Preand post-removal benthic samples were taken at 3 sites in the area cleared of substrates. One site, serving as check, was located upstream in the uncleared area. Midge larvae and pupae belonging to 5 genera were taken. In pre-removal samples taken from the area cleared of substrates, larvae of Cricotopus spp. and Dicrotendipes sp. predominated and formed 89.1% of the total midge fauna. Pupae constituted 10.1% of the total immature midges. The average midge density in the area cleared of substrates was 1303/0.09 m2 prior to the removal of substrates. Samples collected 3 days after removal showed a reduction of 87.0% in the total midge fauna. Satisfactory midge control lasted for 2 weeks. Benthic midge populations recovered completely after 4 weeks.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
