Abstract
Flavoxate was identified as a phytocompound in the C. procumbens leaf methanolic extract using GC-MS analysis. The major phytoconstituent, Flavoxate, was tested according to a standard protocol at various concentrations (3-180 μg/mL) against third-instar larvae and at 5-200 μg/mL against pupae of the vector mosquitoes Ae. aegypti, An. stephensi and Cx. quinquefasciatus, as well as the aquatic non-target fauna Acilius sulcatus, Diplonychus indicus and Anisops bouvieri. GC-MS analysis confirmed the presence of 20 phytocompounds, of which Flavoxate (23.33%) was the major phytoconstituent. The LC50/LC90 values of C. procumbens leaf methanol extract and Flavoxate against third-instar larvae of Ae. aegypti, An. stephensi and Cx. quinquefasciatus were 76.51/171.76, 81.02/178.69, 90.44/175.06, 12.94/21.12, 13.36/25.72 and 13.66/23.43 μg/mL, respectively. Similarly, the LC50/LC90 values against pupae of Ae. aegypti, An. stephensi and Cx. quinquefasciatus were 103.24/191.05, 104.30/190.52, 104.70/198.15, 14.46/26.62, 15.83/32.08 and 17.91/35.87 μg/mL, respectively. At higher concentrations, C. procumbens leaf methanol extract and Flavoxate produced comparatively low susceptibility in the selected non-target fauna, and the suitability indices indicated that these phytopesticides were less harmful to the tested non-target fauna. Moreover, behavioural/survival activities, including swimming, floating, diving, abnormalities, sluggishness, jumping and prey hunting, were not noticeably altered following exposure to the selected phytoproducts. C. procumbens leaf methanol extract and Flavoxate showed high toxicity to juvenile stages of the medical vectors at lower concentrations. Overall, the C. procumbens-derived phytopesticides produced greater adverse effects on the medical vectors than on the selected non-target fauna.