ABSTRACT
Objective: To evaluate the toxicity against house fly Musca domestica L. (M. domestica)-larvicidal, pupicidal, and oviposition deterrent activities of essential oils (EOs) from five plants: Anethum graveolens L. (A. graveolens), Centratherum anthelminticum L. (C. anthelminticum), Foeniculum vulgare Mill. (F. vulgare), Pimpinella anisum L. (P. anisum), and Trachyspermum ammi L. (T. ammi) Sprague. Methods: Dipping, topical and dual-choice assays were performed by using each EO at three concentrations (1%, 5% and 10%) as well as cypermethrin (positive control) and ethyl alcohol (negative control) in order to determine their larvicidal, pupicidal and oviposition deterrent activities against M. domestica mortality rate and morphogenic abnormality of larvae and pupae were recorded after 3 and 10 days of incubation. Oviposition deterrent activity was recorded for 5 consecutive days from the beginning of the assay. Results: All EOs at the highest concentration (10%) were highly effective in oviposition deterrent with 100% effective repellency and an oviposition activity index of -1.00. Ten percent of F. vulgare oil exhibited the highest efficacy against the larvae with 89.6% mortality rate at 3 days and an LC
ABSTRACT
Objective:To evaluate the toxicity against house fly Musca domestica L. (M. domestica)-larvicidal, pupicidal, and oviposition deterrent activities of essential oils (EOs) from five plants: Anethum graveolens L. (A. graveolens), Centratherum anthelminticum L. (C. anthelminticum), Foeniculum vulgare Mill. (F. vulgare), Pimpinella anisum L. (P. anisum), and Trachyspermum ammi L. (T. ammi) Sprague.Methods:Dipping, topical and dual-choice assays were performed by using each EO at three concentrations (1%, 5% and 10%) as well as cypermethrin (positive control) and ethyl alcohol (negative control) in order to determine their larvicidal, pupicidal and oviposition deterrent activities against M. domestica mortality rate and morphogenic abnormality of larvae and pupae were recorded after 3 and 10 days of incubation. Oviposition deterrent activity was recorded for 5 consecutive days from the beginning of the assay.Results:All EOs at the highest concentration (10%) were highly effective in oviposition deterrent with 100% effective repellency and an oviposition activity index of -1.00. Ten percent of F. vulgare oil exhibited the highest efficacy against the larvae with 89.6% mortality rate at 3 days and an LCConclusions:These results indicate that F. vulgare, A. graveolens and T. ammi EOs are effective larvicidal, pupicidal and oviposition deterrent agents against house fly M. domestica.
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
<p><b>OBJECTIVE</b>To evaluate aqueous and ethanol extract of Cassia didymobotrya leaves against immature stages of Culex quinquefasciatus.</p><p><b>METHODS</b>The mortality rate of immature mosquitoes was tested in wide and narrow range concentration of the plant extract based on WHO standard protocol. The wide range concentration tested in the present study was 10 000, 1 000, 100, 10 and 1 mg/L and narrow range concentration was 50, 100, 150, 200 and 250 mg/L.</p><p><b>RESULTS</b>2nd instar larvae exposed to 100 mg/L and above concentration of ethanol extract showed 100% mortality. Remaining stages such as 3rd, 4th and pupa, 100% mortality was observed at 1 000 mg/L and above concentration after 24 h exposure period. In aqueous extract all the stages 100% mortality was recorded at 1 000 mg/L and above concentration. In narrow range concentration 2nd instar larvae 100% mortality was observed at 150 mg/L and above concentration of ethanol extract. The remaining stages 100% mortality was recorded at 250 mg/L. In aqueous extract all the tested immature stages 100% mortality was observed at 250 mg/L concentration after 24 h exposure period. The results clearly indicate that the rate of mortality was based dose of the plant extract and stage of the mosquitoes.</p><p><b>CONCLUSIONS</b>From this study it is confirmed and concluded that Cassia didymobotrya is having active principle which is responsible for controlling Culex quinquefasciatus. The isolation of bioactive molecules and development of simple formulation technique is important for large scale implementation.</p>