Bioefficacy of essential oil from Polygonum hydropiper L. against mosquitoes, Anopheles stephensi and Culex quinquefasciatus

• Confertifolin was isolated from the essential oil of leaves of Polygonum hydropiper.
• Confertifolin showed potential mosquitocidal activity against two vector mosquitoes.
• Confertifolin did not show any toxic effect on non-target organisms.
• The isolated compound confertifolin is eco-friendly and easily biodegradable.

The biological activity of essential oil extracted from the leaves of Polygonum hydropiper and a compound, confertifolin, isolated from this plant was bioassayed against larva of mosquitoes, Anopheles stephensi and Culex quinquefasciatus. The essential oil showed the LC50 values of 189 and 243 ppm; 217 and 242 ppm, confertifolin (6,6,9a-trimethyl-4,5,5a,6,7,8,9,9a-octahydronaphtho[1,2-c]furan-3(1H)-one) showed the LC50 values of 2.40 and 3.09 ppm; 4.07 and 4.18 ppm against the second and fourth instar larvae of An. stephensi and Cx. quinquefasciatus, respectively. At 10 ppm confertifolin showed ovicidal activity of 100, 98.6 and 86.4% against An. stephensi and 100, 100 and 75.2% against Cx. quinquefasciatus on 0–6, 6–12 and 12–18 h old eggs; the repellent activity persisted for 314.6 and 319.0 min; oviposition deterrent activity was 97.2 and 99% and adulticidal activity was 100 and 100% against An. stephensi and Cx. quinquefasciatus, respectively. The results were statistically significant. Confertifolin could be considered for use in the control of human vector mosquitoes.