Larvicidal activity of pectolinaringenin from Clerodendrum phlomidis L. against Culex quinquefasciatus Say and Aedes aegypti L. (Diptera: Culicidae).

Larvicidal activity of 12 fractions and a compound of chloroform extract of Clerodendrum phlomidis L. (Lamiaceae) was assayed for their toxicity against the early fourth-instar larvae of the filarial vector Culex quinquefasciatus Say and dengue vector Aedes aegypti L. The fractions were tested at 100-, 50-, 25- and 12.5-ppm concentrations. The compound pectolinaringenin was tested at 5-, 2.5-, 1.0- and 0.5-ppm concentrations. Among the different fractions, fraction 5 recorded the lowest LC(50) and LC(90) values of 5.02, 61.63 ppm and 32.86, 73.62 ppm against C. quinquefasciatus and A. aegypti, respectively. The compound pectolinaringenin showed the lowest LC(50) and LC(90) values of 0.62, 2.87 ppm and 0.79, 5.31 ppm against C. quinquefasciatus and A. aegypti, respectively. This is the first report on the mosquito larvicidal activity of the isolated compound pectolinaringenin from C. phlomidis. The results of this study show that the chloroform extract of C. phlomidis can be used as a potent source and pectolinaringenin as a new natural mosquito larvicidal agent.

Ovicidal activity of Atalantia monophylla (L) Correa against Spodoptera litura Fab. (Lepidoptera: Noctuidae).

OBJECTIVE: To evaluate the efficacy of Atalantia monophylla (A. monophylla) leaf in different solvent crude extracts and fractions against eggs of Spodoptera litura (S. litura). METHODS: Hexane, ethyl acetate and chloroform solvent extracts of A. monophylla leaf and 12 fractions from hexane extract were screened at 5.0%, 2.5%, 1.0% and 0.5% for crude extracts and 1 000, 500, 250 and 125 mg/kg for fractions against the eggs of S. litura for the ovicidal activity. LC50 and LC90 were calculated using probit analysis. RESULTS: Hexane crude extract showed maximum ovicidal activity of 61.94% at 5.0% concentration with a correlation value of r (2)=0.81, and least LC50 value of 3.06%. Hexane extract was fractionated using silica gel column chromatography and 12 fractions were obtained. Fraction 9 was active which showed maximum ovicidal activity of 75.61% at 1 000 mg/kg with the LC50 value of 318.65 mg/kg and LC90 value of 1 473.31 mg/kg. In linear regression analysis, significant and high correlation (r (2)=0.81%) was seen between concentration and ovicidal activity of hexane crude extracts and its active fraction. CONCLUSIONS: As per our knowledge, this is the first report for ovicidal activity of A. monophylla against S. litura, A. monophylla could be used for the management of S. litura and other insect pests.

Ovicidal activity of Atalantia monophylla (L) Correa against Spodoptera litura Fab. (Lepidoptera:Noctuidae)

Objective: To evaluate the efficacy of Atalantia monophylla (A. monophylla) leaf in different solvent crude extracts and fractions against eggs of Spodoptera litura (S. litura). Methods:Hexane, ethyl acetate and chloroform solvent extracts of A. monophylla leaf and 12 fractions from hexane extract were screened at 5.0%, 2.5%, 1.0%and 0.5%for crude extracts and 1 000, 500, 250 and 125 mg/kg for fractions against the eggs of S. litura for the ovicidal activity. LC50 and LC90 were calculated using probit analysis. Results:Hexane crude extract showed maximum ovicidal activity of 61.94%at 5.0%concentration with a correlation value of r2=0.81, and least LC50 value of 3.06%. Hexane extract was fractionated using silica gel column chromatography and 12 fractions were obtained. Fraction 9 was active which showed maximum ovicidal activity of 75.61%at 1 000 mg/kg with the LC50 value of 318.65 mg/kg and LC90 value of 1 473.31 mg/kg. In linear regression analysis, significant and high correlation (r2=0.81%) was seen between concentration and ovicidal activity of hexane crude extracts and its active fraction. Conclusions:As per our knowledge, this is the first report for ovicidal activity of A. monophylla against S. litura, A. monophylla could be used for the management of S. litura and other insect pests.

Antifeedant, larvicidal and pupicidal activities of Atalantia monophylla (L) Correa against Helicoverpa armigera Hubner (Lepidoptera: Noctuidae).

Antifeedant, larvicidal and pupicidal activities of hexane, chloroform and ethyl acetate extracts of Atlantia monophylla leaf were studied against third instar larvae of Helicoverpa armigera. All the extracts showed feeding deterrent, larvicidal and pupicidal effects in a dose dependent manner. Significant antifeedant, larvicidal and pupicidal activities were observed only in hexane extract. The hexane extract was subjected to fractionation using silica gel column chromatography. Twelve fractions were obtained. Ninth fraction showed good antifeedant, larvicidal, pupicidal activities and disrupted adult emergence. LC(50) value was at 384.57 ppm for larval mortality. The active fraction at 1000 ppm concentration had 100% pupal mortality.