Screening of some weed extracts for ovicidal and larvicidal activities against dengue vector Aedes aegypti

Abstract

Background The use of plant-based formulations is an easy and economical method to control insect pests. The objectives of the present study were to evaluate ovicidal and larvicidal potential of ethanolic leaf extracts of four plants, Cyathocline purpurea, Blumea lacera, Neanotis lancifolia, and Neanotis montholonii, and their effects on gut histology of Aedes aegypti (Diptera: Culicidae) larvae. We identified the phytochemicals present in the ethanolic extracts of these plants by LC-MS analysis. The eggs and larvae of A. aegypti were exposed to four concentrations (0.05, 0.1, 0.2, and 0.3 mg/mL) of crude ethanol extracts for different time durations. We observed egg hatching for 48 h, mortality, and gut histology of the 3rd instar larvae after 24, 48, and 72 h of treatments. Results LC-MS analysis revealed the presence of various active compounds such as alkaloids, tannins, saponins, and flavonoids in the ethanol extracts of all these plants. The extracts of all plants showed ovicidal activity. The extracts of C. purpurea showed the highest larvicidal activity (LC50 at 72 h = 0.088 mg/mL) followed by B. lacera (LC50 at 72 h = 0.758 mg/mL) while N. lancifolia and N. montholonii extracts did not show significant larvicidal activity. All plant extracts affected gut morphology in concentration and treatment duration-dependent manner. The plant extracts used in the present study have ovicidal properties and affected the gut histology of A. aegypti larvae. Conclusion These results suggest that C. purpurea has the highest larvicidal activity against A. aegypti larvae and can be further evaluated for application purposes.

Impact of Caesalpinia pulcherrima (L.) Sw. (Fabaceae) Ethanol and Acetone Leaf Extracts on the Aedes aegypti (Diptera: Culicidae) Eggs

“…aegypti eggs. Extract of all the plants caused 70 to 90% mortality at higher concentrations (Torawane et al, 2021). n-hexane leaf extract of Murraya paniculata showed ovicidal activity on Ae.…”

The Major Phyto-Compounds Heptasiloxane, hexadecamethyl- and 1,1-Dimethylethyl 3-Phenyl-2-Propenoate Derived from Indigofera tinctoria Medicinal Flora Tested Against Various Target Medical and Agronomic Pests

“…Previously, the medicinal flora of Cyathocline purpurea, Blumea lacera, Neanotis montholonii and Neanotis lancifolia extract showed 70-90% eggs toxicity observed at higher concentrations against Ae. aegypti (20) . Sophora alopecuroides derived phyto-constituents Sophocarpin and Sophordine were provided maximum egg toxicity 88.5% 78% at 100 µg/ml against Ae.…”