Utpal Adhikari

In vitro repellent and larvicidal efficacy of Swietenia mahagoni against the larval forms of Culex quinquefasciatus Say

Objective To analyze the mosquito repellency and larvicidal activity of mature leaves of Swietenia mahagoni (S. mahagoni) against Culex quinquefasciatus (Cx. quinquefasciatus) Say in laboratory bioassay.

Laboratory evaluation of ethyl acetate and chloroform: methanol (1:1 v/v) extract of Swietenia mahagoni leaf against Japanese Encephalitis vector Culex vishuni group

Abstract Objective To study the larvicidal activity of a furniture tree Swietenia mahagoni L. ( S. mahagoni ) against mosquito Culex Vishnui group. Methods Different concentrations of crude, chloroform: methanol (1:1 v/v) and ethyl acetate solvent extracts of S. mahagoni mature leaves were treated against Cx. vishnui group larvae. Results Five graded concentrations (0.05%, 0.10%, 0.20%, 0.30% and 0.40%) of crude extract of mature leaves and five graded concentrations (10 ppm, 20 ppm, 30 ppm, 40 ppm and 50 ppm) of chloroform: methanol (1:1 v/v) and ethyl acetate solvent extracts showed significant ( P 0.05) larval mortalities. LC 50 , LC 90 values were calculated at 24 h, 48 h and 72 h of exposures. Adult Cx. vishnui group mosquitoes exposed to burning coils prepared from S. mahagoni mature leaves showed smoke repellency and toxicity up to 4 h. Conclusions This study was a pioneer attempt to establish S. mahagoni as an effective mosquito larvicide.

Larvicidal, smoke toxicity, repellency and adult emergence inhibition effects of leaf extracts of Swietenia mahagoni Linnaeus against Anopheles stephensi Liston (Diptera: Culicidae)

Objective To analyze the larvicidal, smoke toxicity, repellency and adult emergence inhibition activity of crude and solvent extracts of Swietenia mahagoni (S. mahagoni) leaves against larva of Anopheles stephensi (An. stephensi).

Phytochemical Analyses and Larvicidal Potentiality of Fruit Peel Extracts of Citrus limetta against Filarial Vector Culex quinquefasciatus

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.

Biocontrol efficacy of an organic acid against larval form of Culex quinquefasciatus, Culex vishuni group and Anopheles stephensi

Abstract Objective To estimate the larvicidal activities, if any of glacial acetic acid, an organic acid against Culex quinquefasciatus ( Cx. quinquefasciatus ), Culex vishuni ( Cx. vishuni ) group and Anopheles stephensi ( An. stephensi ). Methods The common organic acid, glacial acetic acid at some fixed concentrations(0.1%, 0.2%, 0.3%, 0.4% and 0.5%) were used against third instar larvae of Cx. quinquefasciatus, Cx. vishuni group and An. stephensi in order to investigate the rate of mortality after 24 h, 48 h and 72 h of exposure in laboratory. Results 100% mortality of 3rd instar larva of An. stephensi was recorded at 0.5% concentration after 72 h of exposure. The results or regression analysis revealed that the mortality rate ( Y ) was positively correlate with the period of exposure ( X ). The value of R 2 in all cases was near 1. Conclusions The organic chemical may be used efficiently to kill Cx. quinquefasciatus, Cx. vishuni group and An. stephensi . Acid can be applied both in field condition and laboratory condition.