UTTAR PRADESH JOURNAL OF ZOOLOGY

Mosquito-borne vectors remain important targets for control, while extensive reliance on synthetic chemicals may create environmental concerns. This study evaluated the mosquitocidal activity of the leaf methanol extract of Evolvulus nummularius and its major GC-MS-identified phyto-compound against larvae and pupae of Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. GC-MS analysis of the leaf methanol extract identified 20 phyto-compounds, with 3,9. Beta.:14,15-Diepoxypregn-16-en-20-one, 3,11. beta.,18-triacetoxy- representing the largest chromatographic area (22.33%). Third-instar larvae and newly emerged pupae were exposed to graded concentrations under laboratory conditions. For the leaf methanol extract, larval LC₅₀/LC₉₀ values were 76.67/157.13, 83.35/164.55, and 88.29/178.72 µg/ml for the three species, respectively. For the major phyto-compound, the corresponding larval values were 11.79/25.46, 12.50/23.54, and 12.89/24.00 µg/ml. Pupal LC₅₀/LC₉₀ values for the extract were 102.97/174.73, 110.74/184.22, and 116.73/197.11 µg/ml, whereas those for the major compound were 14.84/25.17, 14.77/24.49, and 14.03/23.05 µg/ml. Both plant-derived products therefore exhibited measurable larvicidal and pupicidal activity under the tested laboratory conditions, with lower lethal-concentration values recorded for the major phyto-compound than for the crude extract. These findings support further investigation of E. nummularius-derived phyto-products for mosquito-control research. Field evaluation and assessment of possible effects on non-target fauna and human health are required before practical application can be considered.