Momordica charantia L. extracts against Aedes aegypti larvae / Extratos de Momordica charantia L. sobre larvas de Aedes aegypti

Mormodica charantia (Curcubitaceae) is a plant with great medicinal potential, also used as an alternative of mosquitoes control as demonstrated by previous studies. We evaluated the larvicidal activity of crude extracts of ethyl acetate, methanol and hexane from flowers and fruits of M. charantia against Aedes aegypti (Culicidae). Flowers and fruits were macerated in methanol, ethyl acetate and hexane. Bioassays were performed with application of the extracts at final concentrations of 1 - 200 µg/mL in the middle of the third instar larvae of A. aegypti (L3). The results showed high toxicity to ethyl acetate extracts from flowers and fruits at concentrations of 200 µg/mL and 100 µg/mL, with 97% and 87% of larvae mortality (L3), respectively. Hexane extract demonstrated low toxicity, while methanol extract exhibited 78% larval mortality. The data suggested that the ethyl acetate extracts of flowers and fruits of M. charantia can effectively contribute to larvicidal activity. In addition, purification of M. charantia extracts may lead to a promising larvicidal activity to control the A. aegypti population.

Mormodica charantia (Curcubitaceae) é uma planta com grande potencial medicinal, sendo também uma alternativa no controle de mosquitos conforme demonstrado por estudos prévios. Avaliou-se a atividade larvicida dos extratos brutos de acetato de etila, metanólico e hexânico das folhas, flores e frutos de M. charantia no Aedes aegypti (Culicidae). Folhas, flores e frutos foram macerados em metanol, acetato de etila e hexano. Os bioensaios foram realizados com aplicação dos extratos nas concentrações finais de 1-200 µg/mL no meio de criação das larvas de terceiro estádio de A. aegypti (L3). Os resultados obtidos apontaram alta toxicidade para os extratos de acetato de etila das flores e frutos nas concentrações de 200 µg/mL e 100 µg/mL com mortalidade em L3 de 96,7% e 87%, respectivamente. Baixa toxicidade para o extrato hexânico e o extrato metanólico apresentou mortalidade de 78% larval. Os dados sugerem que os extratos de acetato de etila das flores e frutos de M. charantia podem contribuir efetivamente para atividade larvicida no controle da população de A. aegypti.

Momordica charantia L. extracts against Aedes aegypti larvae

Abstract Mormodica charantia (Curcubitaceae) is a plant with great medicinal potential, also used as an alternative of mosquitoes control as demonstrated by previous studies. We evaluated the larvicidal activity of crude extracts of ethyl acetate, methanol and hexane from flowers and fruits of M. charantia against Aedes aegypti (Culicidae). Flowers and fruits were macerated in methanol, ethyl acetate and hexane. Bioassays were performed with application of the extracts at final concentrations of 1 - 200 µg/mL in the middle of the third instar larvae of A. aegypti (L3). The results showed high toxicity to ethyl acetate extracts from flowers and fruits at concentrations of 200 µg/mL and 100 µg/mL, with 97% and 87% of larvae mortality (L3), respectively. Hexane extract demonstrated low toxicity, while methanol extract exhibited 78% larval mortality. The data suggested that the ethyl acetate extracts of flowers and fruits of M. charantia can effectively contribute to larvicidal activity. In addition, purification of M. charantia extracts may lead to a promising larvicidal activity to control the A. aegypti population.

Resumo Mormodica charantia (Curcubitaceae) é uma planta com grande potencial medicinal, sendo também uma alternativa no controle de mosquitos conforme demonstrado por estudos prévios. Avaliou-se a atividade larvicida dos extratos brutos de acetato de etila, metanólico e hexânico das folhas, flores e frutos de M. charantia no Aedes aegypti (Culicidae). Folhas, flores e frutos foram macerados em metanol, acetato de etila e hexano. Os bioensaios foram realizados com aplicação dos extratos nas concentrações finais de 1-200 µg/mL no meio de criação das larvas de terceiro estádio de A. aegypti (L3). Os resultados obtidos apontaram alta toxicidade para os extratos de acetato de etila das flores e frutos nas concentrações de 200 µg/mL e 100 µg/mL com mortalidade em L3 de 96,7% e 87%, respectivamente. Baixa toxicidade para o extrato hexânico e o extrato metanólico apresentou mortalidade de 78% larval. Os dados sugerem que os extratos de acetato de etila das flores e frutos de M. charantia podem contribuir efetivamente para atividade larvicida no controle da população de A. aegypti.

Momordica charantia L. extracts against Aedes aegypti larvae / Extratos de Momordica charantia L. sobre larvas de Aedes aegypti

Mormodica charantia (Curcubitaceae) is a plant with great medicinal potential, also used as an alternative of mosquitoes control as demonstrated by previous studies. We evaluated the larvicidal activity of crude extracts of ethyl acetate, methanol and hexane from flowers and fruits of M. charantia against Aedes aegypti (Culicidae). Flowers and fruits were macerated in methanol, ethyl acetate and hexane. Bioassays were performed with application of the extracts at final concentrations of 1 - 200 µg/mL in the middle of the third instar larvae of A. aegypti (L3). The results showed high toxicity to ethyl acetate extracts from flowers and fruits at concentrations of 200 µg/mL and 100 µg/mL, with 97% and 87% of larvae mortality (L3), respectively. Hexane extract demonstrated low toxicity, while methanol extract exhibited 78% larval mortality. The data suggested that the ethyl acetate extracts of flowers and fruits of M. charantia can effectively contribute to larvicidal activity. In addition, purification of M. charantia extracts may lead to a promising larvicidal activity to control the A. aegypti population.

Mormodica charantia (Curcubitaceae) é uma planta com grande potencial medicinal, sendo também uma alternativa no controle de mosquitos conforme demonstrado por estudos prévios. Avaliou-se a atividade larvicida dos extratos brutos de acetato de etila, metanólico e hexânico das folhas, flores e frutos de M. charantia no Aedes aegypti (Culicidae). Folhas, flores e frutos foram macerados em metanol, acetato de etila e hexano. Os bioensaios foram realizados com aplicação dos extratos nas concentrações finais de 1-200 µg/mL no meio de criação das larvas de terceiro estádio de A. aegypti (L3). Os resultados obtidos apontaram alta toxicidade para os extratos de acetato de etila das flores e frutos nas concentrações de 200 µg/mL e 100 µg/mL com mortalidade em L3 de 96,7% e 87%, respectivamente. Baixa toxicidade para o extrato hexânico e o extrato metanólico apresentou mortalidade de 78% larval. Os dados sugerem que os extratos de acetato de etila das flores e frutos de M. charantia podem contribuir efetivamente para atividade larvicida no controle da população de A. aegypti.

Comparative virulence of strains of entomopathogenic nematodes for management of eggplant Grey Weevil, Myllocerus subfasciatus Guerin (Coleoptera: Curculionidae).

The Grey Weevil, Myllocerus subfasciatus Guerin, is an important emerging pest of quarantine significance in Solanaceae crops including the eggplant, Solanum melongena. Entomopathogenic nematodes (EPNs) have been shown to be a potential source of safe and effective control of M. subfasciatus. In this study, we determined the virulence of seven strains of EPNs (Nematoda: Rhabditida) viz. Heterorhabditis bacteriophora NBAIIHb105, H. indica NBAIIHi101, H. indica NBAIIHiMah, Steinernema abbasi NBAIISa01, Steinernema abbasi NBAIISa04, S. carpocapsae NBAIISc04 and S. glaseri NBAIISg01, with different foraging behaviour, against larvae of eggplant grey weevil, M. subfasciatus (Coleoptera: Curculionidae), and their suitability in five representative soils from the eggplant grown areas under laboratory conditions. All seven nematode strains caused >80% mortality of M. subfasciatus larvae at 40 IJs/cm2. LC90 values ranged between 21.18 and 46.41 IJs/cm2 at 96 h post-application, which corresponded to field concentrations between 2.1-4.6×109 IJs/ha. H. indica NBAIIHi101, S. glaseri NBAIISg01, S. abbasi NBAIISa01 and S. carpocapsae NBAIISc04 recorded higher grub mortality, compared to H. indica NBAIIHiMah, H. bacteriophora NBAIIHb05 and S. abbasi NBAIISa04 indicating existence of inter- and intra-specific variation in virulence. Response Surface Modelling (RSM) optimized LC and LT values for maximised larval mortality. RSM predicted a concentration of 58.05-62.54 IJs/cm2 of these EPN (corresponding to a field dose of 5.8-6.2×109 IJs/ha) required for effecting 97.10-99.67% grub mortality, at 90-97 h of exposure. EPN strains performed better in terms of larval mortality in loamy sand, alluvial, mountain soil, red laterite compared to black cotton soils. Efficacy of EPN was positively correlated with the content of sand, and negatively with the clay content. It is possibly the first report that established the potential of local strains of EPNs with different foraging ability and their dosages for suppression of subterranean root feeding larvae of M. subfasciatus in five broad soil types of eggplant grown areas. Validation of this baseline data in real-time eggplant crop situations may help in evolving EPN-based viable management schedules for M. subfasciatus.