Sublethal effects of mosquito larvicides on swimming performance of larvivorous fish Melanotaenia duboulayi (Atheriniformes: Melanotaeniidae).
Laboratory studies were conducted to determine the sublethal effects of exposure to selected larvicides on the critical swimming speed (Ucrit) of crimson-spotted rainbowfish, Melanotaenia duboulayi (Castlenau). This native fish is common throughout southeastern Queensland, and it is increasingly being distributed as a biological control agent of mosquitoes. The selected larvicides included, two organophosphate (OP) compounds (temephos and pirimiphos-methyl), two microbial larvicides (Bacillus thuringiensis spp. israelensis [Bti] de Barjac and Bacillus sphaericus [Bs] Neide), and an insect growth regulator (IGR) (s-methoprene). Exposure to the OP temephos at 10 times the effective field concentration (EFC; 0.33 mg/liter), and OP pirimiphos-methyl at the EFC (0.50 mg/liter), resulted in a significant reduction in the Ucrit of M. duboulayi under controlled conditions. Conversely, exposure to the microbial (Bti and Bs) and IGR (s-methoprene) larvicides at 10 times the EFC had no effect on the Ucrit of M. duboulayi. Accordingly, these products are suitable for integrated pest management programs in Australia.
Hurst
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TP
Queensland Institute of Medical Research and the University of Queensland, Australian Centre for International and Tropical Health and Nutrition, P.O. Royal Brisbane Hospital, Queensland 4029, Australia. tim.hurst@qimr.edu.au
Kay
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BH
Ryan
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Brown
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MD
D000818:Animals; D009033:Culicidae; D004305:Dose-Response Relationship, Drug; D005399:Fishes / Q000502:physiology*; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D008726:Methoprene / Q000633:toxicity; D009946:Organothiophosphorus Compounds / Q000633:toxicity*; D013550:Swimming / Q000502:physiology*; D000002:Temefos / Q000633:toxicity*
D007306:Insecticides; D009946:Organothiophosphorus Compounds; C014153:pirimiphos methyl; D008726:Methoprene; D000002:Temefos