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.
ABSTRACT
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.
ABSTRACT
Objective:To evaluate the efficacy of Thai herbal shampoos [Cartoxylum formosum (C.formosum) + eucalyptus essential oil (EO),C.formosum + citrus EO,Solanum trilobatum + eucalyptus EO,Solanum trilobatum + citrus EO,Moringa oleifera + eucalyptus EO and Moringa oleifera + citrus EO] for killing all stages of Pediculus humanus capitis (Phthiraptera).Methods:A filter paper contact method was applied with three concentrations (0.05,0.10 and 0.20 mL/cm2) of each Thai herbal shampoo as well as permethrin pediculicide (positive control) and drinking water (negative control) against eggs,nymphs and adults of Pediculus humanus capitis.Mortality rates of the eggs were recorded after 7 days of incubation while those of nymphs and adults were recorded after 5 minutes of contact.Results:All herbal shampoos at the high concentration were highly effective against nymphs and adults,but not effective against the eggs.C.formosum + eucalyptus EO and C.formosum + citrus EO shampoos at all concentrations exhibited the highest efficacy against nymphs and adults with 100％ mortality rate at 5 min and LC50 values of 0.004 and 0.005 mL/cm2,respectively.All formulation of Solanum trilobatum and Moringa oleifera shampoos added with eucalyptus EO showed mortality rates against nymphs at 92.0％-100.0％ and 76.0％-100.0％ and against adults at 84.0％-100.0％ and 20.0％-32.0％,respectively.Permethrin pediculicide was not effective against the eggs,but showed 68.0％-92.0％ and 28.0％-60.0％ mortality rates against nymphs and adults.Conclusions:These results indicate that C.formosum + eucalyptus EO shampoo can be used as an effective nymphicide and adulticide against Pediculus humanus capitis.
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.