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Objective: To investigate the efficacies of 12 essential oil (EO) formulations from three Zingiberaceae plants (Alpinia galanga, Curcuma zedoaria, and Zingiber cassumunar) individually and in combination with an augmenting Eucalyptus globulus (E. globulus) EO against females of Aedes albopictus (Ae. albopictus) and Anopheles minimus (An. minimus). Methods: These formulations were evaluated for their ovicidal, oviposition deterrent and adulticidal activities against Ae. albopictus and An. minimus by a topical method, a double-choice method and a WHO susceptibility test, respectively. Results: It was found that all formulations of Zingiberaceae plants EOs augmented with E. globulus EO were more effective in oviposition deterrent, ovicidal, and adulticidal activities against the two mosquito species than all of the formulations used without E. globulus EO. Their oviposition deterrent, ovicidal and adulticidal activities were equivalent to those of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol as a control alone was not effective at all. The highest synergistic effect in effective repellency against Ae. albopictus was achieved by 5% Alpinia galanga EO + 5% E. globulus EO and against An. minimus was 5% Zingiber cassumunar EO + 5% E. globulus EO. Moreover, the highest synergistic effects in ovicidal activities against Ae. albopictus and An. minimus were achieved by 10% Zingiber cassumunar EO + 10% E. globulus EO and 5% Curcuma zedoaria EO + 5% E. globulus EO, respectively. For the adulticidal activities, the highest synergistic effect against two mosquitoes was achieved by 5% Curcuma zedoaria EO + 5% E. globulus EO. Conclusions: These results suggest that Zingiberaceae plant EOs augmented with E. globulus EO have a high potential to be developed into oviposition deterrent, ovicidal, and adulticidal agents for controlling populations of Ae. albopictus and An. minimus.
ABSTRACT
Objective:To investigate the efficacies of 12 essential oil (EO) formulations from three Zingiberaceae plants (Alpinia galanga,Curcuma zedoaria,and Zingiber cas.sumunar) individually and in combination with an augmenting Eucalyptus globulus (E.globulus) EO against females of Aedes albopictus (Ae.adbopictus) and Anopheles minimus (An.minimus).Methods:These formulations were evaluated for their ovicidal,oviposition deterrent and adulticidal activities against Ae.albopictus and An.minimus by a topical method,a double-choice method and a WHO susceptibility test,respectively.Results:It was found that all formulations of Zingiberaceae plants EOs augmented with E.globulus EO were more effective in oviposition deterrent,ovicidal,and adulticidal activities against the two mosquito species than all of the formulations used without E.globulus EO.Their oviposition deterrent,ovicidal and adulticidal activities were equivalent to those of 10％ w/v cypermethrin.In contrast,70％ v/v ethyl alcohol as a control alone was not effective at all.The highest synergistic effect in effective repellency against Ae.albopictus was achieved by 5％ Alpinia galanga EO + 5％ E.globulus EO and against An.minimus was 5％ Zingiber cassumunar EO + 5％ E.globulus EO.Moreover,the highest synergistic effects in ovicidal activities against Ae.albopictus and An.minimus were achieved by 10％ Zingiber cassumunar EO + 10％ E.globulus EO and 5％ Curcuma zedoaria EO + 5％ E.globulus EO,respectively.For the adulticidal activities,the highest synergistic effect against two mosquitoes was achieved by 5％ Gurcuma zedoaria EO + 5％ E.globulus EO.Conclusions:These results suggest that Zingiberaceae plant EOs augmented with E.globulus EO have a high potential to be developed into oviposition deterrent,ovicidal,and adulticidal agents for controlling populations of Ae.albopictus and An.minimus.
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Objective: To evaluate larvicidal, pupicidal and oviposition deterrent activities of four plant essential oils from Alpinia galanga (L.) Willd rhizome, Anethum graveolens L. (An. graveolens)fruit, Foeniculum vulgare Mill. fruit, and Pimpinella anisum L. fruit against Aedes aegypti (Ae. aegypti). Methods: Four essential oils at 1％, 5％ and 10％ concentrations were assessed for insecticidal activity against larvae and pupae of Ae. aegypti, following the procedure of a dipping method assay. Oviposition deterrent activity of four essential oils was evaluated on gravid female of Ae. aegypti by a dual-choice oviposition bioassay. Results: The results revealed that An. graveolens oil provided the strongest larvicidal activity against Ae. aegypti among four tested plant essential oils with the highest mortality rate of 100％ and LC50 value of -0.3％. From the pupicidal experiment, An. graveolens also showed the highest toxicity against Ae. aegypti pupae with the highest mortality rate of 100％ at 72 h and LC50 value of 2.9％. In addition, 10％ An. graveolens had an oviposition deterrent effect against Ae. aegypti with effective repellency of 100％ and an oviposition activity index of –1.0. Conclusions: An. graveolens oil has a good potential as a larvicidal, pupicidal and oviposition deterrent agent for controlling Ae. aegypti.
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Objective To evaluate adulticidal, larvicidal and oviposition deterrent response of the essential oil from dried Zanthoxylum limonella (Z. limonella) fruit against Aedes aegypti (Ae. aegypti) and Culex quinquefasciatus (Cx. quinquefasciatus). Methods Z. limonella oil was tested by biological assays at 1%, 5% and 10% concentrations in ethanol. Adulticidal efficacy was tested against the 2–3 day old adult females. Larvicidal activity was tested against immature stage of mosquitoes. Oviposition deterrence of the oil was evaluated on gravid females. Results The adult mortality was observed after 24 h with the LC
ABSTRACT
Objective:To evaluate adulticidal,larvicidal and oviposition deterrent response of the essential oil from dried Zanthoxylum limonella (Z.limonella) fruit against Aedes aegypti (Ae.aegypti) and Culex quinquefasciatus (Cx.quinquefasciatus).Methods:Z.limonella oil was tested by biological assays at 1％,5％ and 10％ concentrations in ethanol.Adulticidal efficacy was tested against the 2-3 day old adult females.Larvicidal activity was tested against immature stage of mosquitoes.Oviposition deterrence of the oil was evaluated on gravid females.Results:The adult mortality was observed after 24 h with the LC5o of 6.0％ for Ae.aegypti,and 5.7％ for Cx.quinquefasciatus.Larvicidal bioassay was carried out with the 10％ Z.limonella oil against immature stages of Ae.aegypti and Cx.quinquefasciatus,which caused 100％ mortality after 12 h and 24 h.In the larvicidal experiment,Z.limonella showed effective result at 1％,5％ and 10％ concentrations with the values of LT5o Ae.aegypti =9.78,5.61,0.24 h for larvae and LT5o =64.08,21.23 h for pupae;Cx.quinquefasciatus had LT50 =28.46,20.25,1.01 h for larvae and LT50 =67.52,27.96,4.11 h for pupae,respectively.Oviposition deterrence of the oil was evaluated on gravid females.In the study,10％ Z.limonella showed 100％ repellency for Ae.aegypti and 99.53％ for Cx.quinquefasciatus.Likewise,oviposition activity indexes of these oil concentrations were all negative values ranging from-0.89 to-1.00 for Ae.aegypti and-0.64 to-0.99 for Cx.quinquefasciatus.The oviposition activity indexes values revealed that Z.limonella oil has deterrent effect,and it caused a remarkable negative response resulting in very few eggs.Conclusions:This result indicates that Z.limonella oil can be used as an effective adulticide,larvicide and oviposition deterrent against Ae.aegypti and Cx.quinquefasciatus.
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Twelve fractions from chloroform extract of Clerodendrum phlomidis and 5,7-dihydroxy- 4',6-dimethoxy-flavone (pectolinaringenin) were evaluated against Helicoverpa armigera. Maximum antifeedant (89.41%), larvicidal (83.77%) and ovicidal (69.25%) activities were observed in fraction 5. The least LC50 value for antifeedant (178.09 ppm) and larvicidal (198.23 ppm) were observed in fraction 5. No adult emergence was recorded in fractions 4-6 at 1000 ppm. The oviposition deterrent activity was 100% in fraction 5 at all the concentrations. Pectolinaringenin recorded maximum antifeedant (74.68%) and larvicidal (81.11%) activities at 100 ppm; it completely prevented the adult emergence of H. armigera at 100 ppm. Maximum ovicidal activity at 100 ppm concentration was 67.95%. The oviposition deterrent activity was 100% in 100 and 50 ppm concentrations. C. phlomidis could be effectively used to develop a new formulation to control the economically important pests.
ABSTRACT
Background & objectives: Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of plant origin may serve as suitable alternative biocontrol techniques in the future. The purpose of the present study was to assess the ethyl acetate, acetone and methanol extracts of Andrographis paniculata, Eclipta prostrata and Tagetes erecta leaves tested for oviposition-deterrent, ovicidal and repellent activities against malaria vector, Anopheles subpictus Grassi (Diptera: Culicidae). Methods: The dried leaves of the three plants were powdered mechanically and extracted with ethyl acetate, acetone and methanol. One gram of crude extract was first dissolved in 100 ml of acetone (stock solution). From the stock solution, test solution concentrations of 31.21- 499.42 mg/l for oviposition- deterrence assay and repellency and 15.60 - 998.85 mg/l were used in ovicidal assay. The percentage oviposition- deterrence, hatching rate of eggs and protection time were calculated. One-way analysis of variance was used for the multiple concentration tests and for per cent mortality to determine significant treatment differences. Results: The percentage of effective oviposition repellency was highest at 499.42 mg/l and the lowest at 31.21 mg/l in ethyl acetate, acetone and methanol extracts of A. paniculata, E. prostrata and T. erecta. The oviposition activity index (OAI) value of ethyl acetate, acetone and methanol extracts of A. paniculata, E. prostrata and T. erecta at 499.42 mg/l were -0.91, -0.93, -0.84, -0.84, -0.87, -0.82, -0.87, -0.89 and -0.87, respectively. Mortality (no egg hatchability) was 100 per cent with ethyl acetate and methanol extracts of A. paniculata, E. prostrata and T. erecta at 998.85 mg/l. The maximum adult repellent activity was observed at 499.42 mg/l in ethyl acetate extracts of A. paniculata, E. prostrata and methanol extracts of T. erecta, and the mean complete protection time ranged from 120 to 150 min with the different extracts tested. Interpretation & conclusions: The acetone extract of A. paniculata, methanol extract of E. prostrata and T. erecta showed good oviposition-deterrent, ovicidal and repellent activities respectively. These results suggest that the leaf extracts of A. paniculata, E. prostrata and T. erecta may have the potential to be used as an ideal eco-friendly approach for the control of the An. subpictus.