Laboratory studies on the susceptibility of mosquito-eating fish, Lebistes reticulatus and the larvae of Culex pipiens fatigans to insecticides
Chen, P.S.; Lin, Y.N.; Chung, C.L.
Journal of the Formosan Medical Association 70(1): 28-35
1971
ISSN/ISBN: 0371-7682 PMID: 4103471 Document Number: 39353
An account is given of tests of the susceptibility to various insecticides of larvae of Culex pipiens fatigans Wied. and the fish Poecilia (Lebistes) reticulata, which is a useful predator of mosquito larvae. The aim was to find the most suitable insecticide for use in an integrated control programme. DDT and gamma BHC(lindane) were toxic to both C. p. fatigans and P. reticulata. Propoxur and carbaryl were less toxic to P. reticulata but are considered too costly to be suitable larvicides. Apart from parathion, the organophosphorus compounds used (diazinon, malathion and fenitrothion) had low toxicities for P. reticulata and high toxicities for C. p. fatigans. Fenitrothion had an LC95 of 0.035 p.p.m. for the larvae and an LC50 of 2.5 p.p.m. for the fish. When the fish were exposed to 7 p.p.m. of each insecticide for 30 min, DDT had no effect and the next best were diazinon and fenitrothion. Fenitrothion caused many of the fish to lose their equilibrium, but those affected in this way recovered a few hours after release into fresh water.