Short-term toxicity of pyraclofos used as a blackfly larvicide on non-target aquatic fauna in a tropical environment
Autor: | Yaméogo, L., Tapsoba, J.-M., Bihoum, M., Quillévéré, D. |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
aquatic fauna
Surveillance RNK protection de l’écosystème insecticide biologique Côte d’Ivoire Environmental Studies onchocercose pyraclofos factorial correspondence analysis simuliidae vecteur milieu aquatique larve insecticide chimique NAT011000 blackfly larvicide bioassay méthode de lutte West Africa parasite |
Popis: | Among the many larvicides tested for the control of Simulium damnosum s.l. larvae, the vector of human onchocerciasis in West Africa, pyraclofos proved to be 100% effective at 100 µg x L-1 for 10 min in river, with a cany of 20 km at 100m3 xsec-1. Tests were then performed both in laboratory and field conditions to evaluate its toxicity on the non-target aquatic fauna. In experimental short-term gutter tests, the detachment of the total benthic insects was 35% al 100 µg x L-1 for 10 min against 17% for temephos at the same dose and 59% for chlorphoxim at 50 µg x L-1 for 10 min. Centroptilum, Baetis and Pseudopannota bertrandi were the most affected organisms. The treatment of a river resulted in a considerable detachment of the same taxonomic groups, plus Orthocladiinae. On the other hand, investigations conducted in tanks showed that the 24-hr LC50 for Chrysichthys nigrodigitatus is 150 µg x L-1 and that for Pollimyrus isidori 170 µg x L-1, values which are not very different from the operational dose of the larvicide (100 µg xL-1 for 10 min.). Nevertheless, in a river, no fish mortality was recorded. Based on fish LC50 and drift of benthic insects, pyraclofos at 100 µg x L-1 was judged to be less toxic to aquatic fauna in the short term than permethrin and carbosulfan. |
Databáze: | OpenAIRE |
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