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Different concentrations of crude and different solvents viz., n-hexane, ethyl acetate, and methanol fruit peel extracts of Citrus limetta Risso ( C. limetta ) were taken for investigation for larvicidal activity against Culex quinquefasciatus Say, 1823 ( Cx. quinquefasciatus ) mosquito species. Crude extract showed good larvicidal activity with very low concentrations against 1 st - 4 th instars larvae. Only 3 rd instar larvae were taken for larvicidal bioassay experiments for each solvent extract. LC 50 values of n-hexane, ethyl acetate, and methanol fruit peel extracts of C. limetta were 661.27, 1268, and 939.43 ppm respectively after 24 h of exposure. No mortality was observed on control treatments. Log probit analyses, regression equations, and R 2 values of larvicidal bioassay experiments with crude and different solvent extracts were determined. Statistical justification was done through ANOVA analyses. Qualitative phytochemical analyses were carried out and detected different secondary metabolites. No mortality was observed on tested non target organisms.

Crude, and three different solvents, viz., n- hexane, ethyl acetate, and methanol fruit peel extracts of Citrus maxima Merr. ( C. maxima ) were applied at dose dependent manner for larvicidal bioassay against Culex quinquefasciatus Say, 1823 ( Cx. quinquefasciatus ) mosquito. All instars larvae were used for larvicidal bioassay of crude fruit peel extract and only 3 rd instar larvae were used for larvicidal bioassay of different solvent extracts. Log-probit analyses along with Regression equations and R 2 values were determined for larvicidal activity of both crude and different solvent extracts. An ANOVA analysis was carried out to justify the statistical significance. Qualitative phytochemical analyses were done. n-Hexane fruit peel extract was also applied on non target organisms. Crude fruit peel extract of C. maxima showed strong lethal activity against all instars larvae of Cx. quinquefasciatus . 1 st instar larvae were most susceptible to crude fruit peel extract. 1 st instar larvae showed 100% mortality only at 0.2% concentration of crude fruit peel extract after 72 h of exposure. 100% mortality of 3 rd instar larvae were observed at 400 ppm concentration of n-hexane fruit peel extract after 24 h of exposure whereas, ethyl acetate and methanol fruit peel extracts showed 100% mortality at 800 ppm concentration after 72 and 24 h of exposure respectively. LC 50 values of n-hexane, ethyl acetate and methanol fruit peel extracts were 204.60, 640.95, and 336.36 ppm, respectively against 3 rd instar larvae after 24 h of exposure. No mortality was observed on control treatments. Fruit peel extract contained different phytochemical constituents. Non-target organisms did not show any abnormal activity and mortality.

Present study was undertaken to evaluate the mosquito larvicidal potentiality of root extracts of Annona reticulata Linn. ( A. reticulata ), family Annonaceae against filarial vector Culex quinquefasciatus Say, 1823 ( Cx. quinquefasciatus ). Petroleum ether, hexane, and ethyl acetate root extracts of the plant were examined to established their larvicidal potentiality against 3 rd instar larvae of Cx. quinquefasciatus mosquito species. Crude and only ethyl acetate root extracts of the plant at different concentrations were examined on 1 st - 4 th instars larvae of Cx. quinquefasciatus . LC 50 value of ethyl acetate extract after 24 h of exposure against 3 rd instar larvae of Cx. quinquefasciatus were also examined on some non target organisms. Phytochemical analyses of the root extracts of A, reticulata were also investigated. 100% mortality were noticed at very low concentrations of petroleum ether, hexane, and ethyl acetate root extracts of A. reticulata against 3 rd instar larvae of Cx. quinquefasciatus . LC 50 and LC 90 values of ethyl acetate root extract was lower than petroleum ether and hexane root extracts after 24, 48, and 72 h of exposure. Crude and ethyl acetate root extracts showed excellent larvicidal activity against Cx. quinquefasciatus mosquito species. 100% mortality was observed at very low concentration for crude and ethyl acetate root extracts. LC 50 and LC 50 values gradually decreased with time of exposure for crude and ethyl acetate root extracts of A. reticulata . No mortality and sluggishness were observed in control experiments as well as on examined non target organisms. Phytochemical analyses of root extracts of the plant revealed the presence of different secondary metabolites. So crude and ethyl acetate root extracts of A. reticulata can effectively be used for larval mortality against Cx. quinquefasciatus mosquito species at a very low concentration.

One of the promising ways to reduce mosquito population is the use of larvicide. Curcuma aromatica is a cosmetic herb in South Asia . The present study was conducted to explore the larvicidal effect of Curcuma aromatica rhizome extracts against the Culex vishnui group. To assess the larvicidal activity, crude extracts of rhizome of Curcuma aromatica were prepared ranging from 0.02% to 0.1% concentrations against all the instars of Cx. vishnui larvae. Active fractions were obtained by using six different solvents i.e. petroleum ether, n-hexane, ethyl acetate, chloroform: methanol (1:1 v/v), acetone, and absolute alcohol from non-polar to polar fashion. All the solvent extractives were tested against all the larval instars with graded concentrations ranging from 20 ppm to 100 ppm. Through log–probit analyses, LC 50 and LC 90 values were determined. Afterwards the statistical justifications were done by ANOVA analyses with reference to time, concentrations and larval instars as three entirely randomized autonomous variables. Furthermore the bioactive fraction was tested against non-target organisms under laboratory conditions. Maximum mortality was recorded in 0.1% concentrations of crude rhizome extracts against all the instars. Ethyl acetate extractives were found to have good larvicidal effect only among all the solvent extractives. The LC 50 and LC 90 values of 3 rd instars larvae were 17.25 ppm and 78.02 ppm respectively after 72 h of post exposure.The non-responsiveness of the non-target populations towards extractives was also noticed. The rhizome extracts of Curcuma aromatica can be used as an alternative larvicide against the JE vector Cx. vishnui group.