Larvicidal Activity Of Essential Oil Research Articles

Synthesis of eco-friendly layered double hydroxide and nanoemulsion for jasmine and peppermint oils and their larvicidal activities against Culex pipiens Linnaeus

Mosquito-borne diseases represent a growing health challenge over time. Numerous potential phytochemicals are target-specific, biodegradable, and eco-friendly. The larvicidal activity of essential oils, a jasmine blend consisting of Jasmine oil and Azores jasmine (AJ) (Jasminum sambac and Jasminum azoricum) and peppermint (PP) Mentha arvensis and their nanoformulations against 2nd and 4th instar larvae of Culex pipiens, was evaluated after subjecting to different concentrations (62.5, 125, 250, 500, 1000, and 2000 ppm). Two forms of phase-different nanodelivery systems of layered double hydroxide LDH and oil/water nanoemulsions were formulated. The synthesized nanoemulsions showed particle sizes of 199 and 333 nm for AJ-NE and PP-NE, with a polydispersity index of 0.249 and 0.198, respectively. Chemical and physiochemical analysis of TEM, SEM, XRD, zeta potential, drug loading capacity, and drug release measurements were done to confirm the synthesis and loading efficiencies of essential oils' active ingredients. At high concentrations of AJ and PP nanoemulsions (2000 ppm), O/W nanoemulsions showed higher larval mortality than both LDH conjugates and crude oils. The mortality rate reached 100% for 2nd and 4th instar larvae. The relative toxicities revealed that PP nanoemulsion (MA-NE) was the most effective larvicide, followed by AJ nanoemulsion (AJ-NE). There was a significant increase in defensive enzymes, phenoloxidase, and α and β-esterase enzymes in the treated groups. After treatment of L4 with AJ, AJ-NE, PP, and PP-NE, the levels of phenoloxidase were 545.67, 731.00, 700.00, and 799.67 u/mg, respectively, compared with control 669.67 u/mg. The activity levels of α-esterase were 9.71, 10.32, 8.91, and 10.55 mg α-naphthol/min/mg protein, respectively. It could be concluded that the AJ-NE and PP-NE nanoformulations have promising larvicidal activity and could act as safe and effective alternatives to chemical insecticides.

Chemical composition, antimicrobial and larvicidal activities of essential oils of two Syzygium species from Vietnam.

The present study is the first to investigate the chemical composition, antimicrobial and larvicidal activities of the essential oils from the leaves of Syzygium attopeuense (Gagnep.) Merr. & L.M.Perry and Syzygium tonkinense (Gagnep.) Merr. & L.M.Perry collected in Vietnam. The essential oils were extracted by hydrodistillation and analyzed by GC and GC-MS. The study indicated the presence of a high percentage of sesquiterpenes in both investigated essential oils. The major components of S. attopeuense essential oil were bicyclogermacrene (24.26%), (E)-caryophyllene (11.72%), and (E)-β-ocimene (6.75%), whereas S. tonkinense essential oil was dominated by (E)-caryophyllene (80.80%). The antimicrobial activity of essential oils was evaluated by broth microdilution assay to determine the minimum inhibitory concentration (MIC) and median inhibitory concentration (IC50). Both essential oils exhibited remarkable inhibitory activity against all tested Gram-positive bacteria and yeast than Gram-negative bacteria. Among them, essential oils of S. attopeuense and S. tonkinense possessed the strongest activity against Enterococcus faecalis (MIC = 4.00 μg/mL; IC50 = 1.69 μg/mL) and Candida albicans (MIC = 16.00 μg/mL; IC50 = 8.67 μg/mL), respectively. Furthermore, the larvicidal activity of essential oils was tested using fourth-instar larvae of Aedes aegypti. Results from the larvicidal test revealed that both essential oils had an excellent inhibitory effect against A. aegypti larvae with LC50 values from 25.55 to 30.18 μg/mL and LC90 values from 33.00 to 39.01 μg/mL. Our findings demonstrate that the essential oil extracted from S. attopeuense and S. tonkinense are potential sources of natural antimicrobials and can act as inexpensive mosquito larvicidal agents.

Chemical Composition and Larvicidal Activity of Essential Oil from Leaves Eugenia catharinae

Chemical Composition and Larvicidal Activity of Essential Oil from Leaves Eugenia catharinae

Larvicidal activity of essential oils of Haridra and Tulsi against Aedes aegypti and Anopheles larvae

An attempt is made in the present study to analyse the larvicidal activity of Haridra and Tulsi against Aedes and Anopheles larvae. Larval bioassays were carried out at different concentrations 50-500ppm. The larval mortality of fourth instar larvae of A. aegypti and Anopheles after 24h of treatment was observed separately in control, 50, 62.5, 100, 150, 250, 300 and 500 ppm concentrations. Based on the Probit analysis, Significant effect (Estimate adh_conc = 3.069, 95% C.I. [2.082, 4.057], z = 6.093, p<.05) of Haridra oil extract concentration for Aedes (adh_conc) on the Probit response or mortality was observed. The median lethal Concentration, LC50= 166.353, 95% C.I. [134.745, 203.268], 90% Lethal Concentration, LC90 = 435.065, 95% C.I. [328.259, 712.462] were recorded. Statistical analysis revealed that significant effect (Estimate adt_conc = 3.369, 95% C.I. [2.229, 4.509], z = 5.791, p<.05) of Tulsi oil extract on Aedes larvae concentration (adt_conc) on the Probit response or larvae mortality (adt_mort) was observed. The median Lethal Concentration, LC50= 105.051, 95% Confidence Intervals (C.I). [81.451, 127.428], 90% Lethal Concentration, LC90 = 252.242, 95% C.I. [199.229, 376.772] of essential oil of Tulsi oil against Aedes aegypti larvae was recorded. No mortality of Aedes larvae was recorded in the control group. Essential oil of Haridra at different concentrations shows a significant effect (Estimate anh_conc = 2.038, 95% C.I. [1.180, 2.896], z = 4.655, p<.05 against the mortality of Anopheles Larvae on the Probit response or mortality. The median Lethal Concentration, LC50 = 124.823, 95% Confidence interval CI. [84.002, 164.336], 90% Lethal Concentration, LC90 = 530.978, 95% C.I. [349.474, 1333.827] of essential oil of Curcuma longa against Anopheles larvae was recorded. (Estimate ant_conc = 2.257, 95% C.I. [1.135, 3.200], z = 4.694, p<.05) of Tulsi oil - extract on Anopheles Larvae concentration (ant_conc) on the Probit response or mortality (ant mort) was observed. Median Lethal Concentration, LC50 = 339.419, 95% Confidence Interval (C.I.) [259.239, 533.727], 90% Lethal Concentration, LC90 = 1254.519, 95% C.I. [717.77, 4574.12] of essential oil of Tulsi oil against Anopheles larvae. Larvicidal activity of both the plants against Aedes larvae at different concentration was significant. But LC50 and LC90 values of Ocimum sanctum (Tulsi) against mortality of Aedes aegypti were less as compared to Curcuma longa (Haridra). It revealed that Tulsi showed better larvicidal activity against Aedes larvae as compared to Haridra. It was also observed that LC50 and LC90 values of Haridra against Anopheles larvae were less than Tulsi. It revealed that Haridra showed better larvicidal activity against Anopheles larvae as compared to Tulsi.

Essential oils of the ginger plants Meistera caudata and Conamomum vietnamense: chemical compositions, antimicrobial, and mosquito larvicidal activities.

The current study describes the chemical identification, antimicrobial, and mosquito larvicidal activities of essential oils from Meistera caudata and Conamomum vietnamense, growing in Vietnam. Essential oils were extracted from the leaves and rhizomes, and characterized by the GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analysis. Monoterpenes (33.1-89.2 %) were the main chemical class found in these oils. β-Pinene (30.8 %) and α-pinene (23.8 %) were two major compounds in M.caudata leaf oil. C.vietnamense leaf and rhizome essential oils were dominated by 1,8-cineole (47.9-62.0 %) and limonene (10.3-16.2 %). With the same MIC (minimum inhibitory concentration) value of 25 μg/mL, C.vietnamense leaf and rhizome essential oils strongly inhibited the growth of Gram-positive bacteria Staphylococcus aureus ATCC 29213 and Bacillus subtilis ATCC 6501, respectively. For 24 and 48-h treatments, C.vietnamense leaf essential oil strongly controlled the growth of mosquito Aedes aegypti with the respective LC50 values of 7.67 and 6.73 μg/mL, and the respective LC90 values of 13.37 and 10.83 μg/mL. In the same manner, C.vietnamense rhizome essential oil also showed strong mosquito larvicidal activity against Aedes albopictus with the LC50 values of 12.37 and 12.00 μg/mL, and the LC90 values of 20.56 and 18.58 μg/mL, respectively. C.vietnamense essential essential oils containing a high amount of 1,8-cineole are generally better than M.caudata essential essential oils in both two biological assays.

Chemical Composition and Larvicidal Activity of Essential Oil from Miconia cuspidata

Chemical Composition and Larvicidal Activity of Essential Oil from Miconia cuspidata

Optimization of inclusion complex’s preparation of Psidium cattleyanum S. essential oil and 2-hydroxypropyl-β-cyclodextrin by central composite design for application as larvicide in Aedes aegypti L

The present investigation described the preparation of 2-hydroxypropyl-β-cyclodextrin (HPβCD) inclusion complex (IC) of the essential oil (EO) of Psidium cattleyanum (CAT) and the Aedes aegypti larvicidal evaluation of the EO and IC. The EO was extracted from the leaves of CAT with a 0.79% (m m−1) yield. It is mainly composed of sesquiterpenes, with β-caryophyllene being the major component (34.2%). To achieve optimized conditions for the preparation of the IC, through the physical method of kneading, the parameters molar ratio of EO/HPβCD and the kneading time were evaluated. The best molar ratio of EO:HPβCD was 1:1.14 and the kneading time corresponded to 30 min. The amount of essential oil loaded under optimized conditions was (94.9 ± 1.7)%. The prepared IC was characterized by spectroscopy in the UV-Vis region, FTIR, TGA, DLS, and XRD to prove the interaction of the EO with the HPβCD. The release of EO from the IC was evaluated in aqueous media using 1% DMSO (v v−1) and acetonitrile. The EO slowly released into the aqueous medium, which was used to simulate the aquatic environment in which A. aegypti larvae develop. The larvicidal activity of CAT EO in DMSO was 81.73 and 102.50 µg mL−1 for LC50 and LC90, respectively. The IC's toxicity was 134.44 and 168.69 µg mL−1 for LC50 and LC90, respectively. Although the larvicidal activity of EO is higher as compared to the IC, the latter presents great thermal stability and high water solubility. Taking together, the described in this study points to the fact that IC prepared from CAT EO may represent a good alternative for A. aegypti larvae control.

Evaluation of the larvicidal activity of essential oil from needles of Pinus halepensis against defoliating caterpillars of Quercus spp. in North Africa

This work aims to study the management of Lepidoptera defoliators of Quercus spp. using essential oil of Pinus halepensis needles. In this context, laboratory trials of two concentrations (0.1 % and 0.5%) compared with ethanol (negative control) and delthametrin (positive control) were tested by contact action on 3rd, 4th and 5th instars larvae of two outbreak species: the Tortricidae, Tortrix viridana and the Geometridae, Operophtera brumata. Results revealed that P. halepensis essential oil has significant insecticidal potentials on both Lepidoptera species. Essential oil at 0.1 % was three time more efficient on the 3rd instar of T. viridana than on O. brumata. However, mature larvae (4th and 5th instars) took more time to die. The major components of P. halepensis were α-pinene (46.1%) and β-myrcene (9.5%) that may show their insecticidal effectiveness on these pests.
 In conclusion, these results are promoting and seems to be of major importance in regulating pests but not outbreaks. Thus, further studies are required to isolate bioactive components and to elucidate the insecticidal mechanisms of P. halepensis.

Chemical composition and larvicidal activity of essential oils of three Artemisia species

AbstractAedes aegypti L. (Diptera: Culicidae) is a vector for serious diseases in tropical regions. This pest is mainly controlled by commercial larvicides but the application of such products has led to environmental problems. Essential oils (EO) have been consistently reported as molecules with insecticidal activity and can be used to produce more environmentally friendly larvicides in the control of A. aegypti. In this study, the larvicidal effect of essential oils (EO) from the leaves of three Artemisia species was evaluated against A. aegypti. The oils were obtained from steam distillation and their chemical composition was determined by gas chromatography–mass spectrometry. The EO of Artemisia camphorata was the most active in the screening bioassay and presented LC50 and LC95 of 64.95 and 74.18 μg ml−1, respectively. In addition, we found that germacrene D‐4‐ol was the constituent responsible for the toxicity of this EO. Artemisia camphorata EO and its major constituent, germacrene D‐4‐ol, are promising for the development of natural larvicides against A. aegypti.

Studies on the Phytochemical Profile of Ocimum basilicum var. minimum (L.) Alef. Essential Oil, Its Larvicidal Activity and In Silico Interaction with Acetylcholinesterase against Aedes aegypti (Diptera: Culicidae).

Aedes aegypti L. (Diptera: Culicidae) is an important transmitter of diseases in tropical countries and controlling the larvae of this mosquito helps to reduce cases of diseases such as dengue, zika and chikungunya. Thus, the present study aimed to evaluate the larvicidal potential of the essential oil (EO) of Ocimum basilicum var. minimum (L.) Alef. The EO was extracted by stem distillation and the chemical composition was characterized by gas chromatography coupled with mass spectrometry (GC/MS and GC-FID). The larvicidal activity of EO was evaluated against third instar Ae. aegypti following World Health Organization (WHO) standard protocol and the interaction of the major compounds with the acetylcholinesterase (AChE) was evaluated by molecular docking. The predominant class was oxygenated monoterpenes with a concentration of 81.69% and the major compounds were limonene (9.5%), 1,8-cineole (14.23%), linalool (24.51%) and methyl chavicol (37.41%). The O. basilicum var. minimum EO showed unprecedented activity against third instar Ae. aegypti larvae at a dose-dependent relationship with LC50 of 69.91 (µg/mL) and LC90 of 200.62 (µg/mL), and the major compounds were able to interact with AChE in the Molecular Docking assay, indicating an ecological alternative for mosquito larvae control.

Study on components and larvicidal activities of essential oils of different parts of Prangos ferulacea plant against larvae of Cx. quinquefasciatus and Anopheles stephensi

Study on components and larvicidal activities of essential oils of different parts of Prangos ferulacea plant against larvae of Cx. quinquefasciatus and Anopheles stephensi

Larvicidal activities of some plants essential oils of the Cameroonian flora against Anopheles gambiae S.L., major vector of malaria in the city of Douala

The present study aims to investigate the larvicidal activity of essential oils of the rhizomes of Zingiber officinalis, the leaves of Tithonia diversifolia and Bidens pilosa on the mature and immature larvae of Anopheles gambiae s.l. The chemical composition of the essential oils was determined by Gas Chromatography (GC) and Gas Chromatography and Mass Spectrometry (GC/MS) coupling. The larvicidal activities of essential oils against An. gambiae s.l. was monitored in the laboratory using the world health organisation protocol. Chemical analysis has shown that all these oils are dominated by monoterpene α-pinene was the major compound found in the essential oils of the leaves of T. diversifolia (69.53%) and B. pilosa (64.43%); while geranial was the majority compound found in the essential oil of Z. officinalis (35.40%). Larvicidal tests showed that the essential oil of the leaves of T. diversifolia was the most effective (LC50 = 70.18 ppm and 92.49 ppm respectively for larvae of immature and mature stages after 24 hours of exposure). From the above, the essential oil of the leaves of T. diversifolia can be recommended for the development of natural biocides against malaria vectors.

Chemical composition and insecticidal activity of Garcinia gardneriana (Planchon & Triana) Zappi (Clusiaceae) essential oil

The present study aimed to analyze the chemical composition of the essential oil from Garcinia gardneriana (Planchon & Triana) Zappi leaves and fruits, and to determine its acaricidal activity on Rhipicephalus microplus by larval packet test and larvicidal action on Aedes aegypti by larval immersion test. The chemical analysis of the essential oil by gas chromatography-mass spectrometry identified sesquiterpene hydrocarbons and oxygenated sesquiterpenes in bacupari leaves and fruits, and α-cedrene, α-chamigrene, α-trans-bergamotene, and β-curcumene as major compounds. Essential oil from leaves of G. gardneriana presented acaricidal activity on R. microplus (LC50 = 4.8 mg/mL; LC99 = 10.8 mg/mL) and larvicidal effect on A. aegypti (LC50 = 5.4 mg/mL; LC99 = 11.6 mg/mL), whereas essential oil from the fruits of G. gardneriana showed LC50 = 4.6 mg/mL and LC99 = 8.9 mg/mL against R. microplus and LC50 = 6.4 mg/mL and LC99 = 13.9 mg/mL against A. aegypti. These results thus demonstrate the potential acaricidal and larvicidal activity of essential oil of G. gardneriana, offering new perspectives for the realization of bioassays from this essential oil.

Larvicidal Activity of Essential Oils From Piper Species Against Strains of Aedes aegypti (Diptera: Culicidae) Resistant to Pyrethroids.

The continuous and indiscriminate use of insecticides has been responsible for the emergence of insecticide resistant vector insect populations, especially in Aedes aegypti. Thus, it is urgent to find natural insecticide compounds with novel mode of action for vector control. The goal of this study was to investigate the larvicidal activity of essential oils (EOs) from Piper species against A. aegypti characterized as resistant and susceptible strains to pyrethroids. The EOs from leaves of 10 Piper species were submitted to the evaluation of larvicidal activity in populations of A. aegypti in agreement with the (World Health Organization, 2005) guidelines. The resistance of the strains characterized by determining the lethal concentrations (LCs) with the insecticide deltamethrin (positive control). The major compounds of the EOs from Piper species was identified by GC-MS. The EOs from Piper aduncum, P. marginatum, P. gaudichaudianum, P. crassinervium, and P. arboreum showed activity of up to 90% lethality at 100 ppm (concentration for screening). The activities of the EOs from these 6 species showed similar LCs in both susceptible strain (Rockefeller) and resistant strains (Pampulha and Venda Nova) to pyrethroids. The major compounds identified in the most active EO were available commercially and included β-Asarone, (E)-Anethole, (E)-β-Caryophyllene, γ-Terpinene, p-Cymene, Limonene, α-Pinene, and β-Pinene. Dillapiole was purified by from EO of P. aduncum. The phenylpropanoids [Dillapiole, (E)-Anethole and β-Asarone] and monoterpenes (γ-Terpinene, p-Cymene, Limonene, α-Pinene, and β-Pinene) showed larvicidal activity with mortality between 90 and 100% and could account for the toxicity of these EOs, but the sesquiterpene (E)-β-Caryophyllene, an abundant component in the EOs of P. hemmendorffii and P. crassinervium, did not show activity on the three populations of A. aegypti larvae at a concentration of 100 ppm. These results indicate that Piper's EOs should be further evaluated as a potential larvicide, against strains resistant to currently used pesticides, and the identification of phenylpropanoids and monoterpenes as the active compounds open the possibility to study their mechanism of action.

Chemical composition and larvicidal activity of essential oil of the bark of Citrus sinensis (L.) Osbeck

Aim: We determined the chemical composition and larvicidal activity of the essential oil distilled from the Citrus sinensis (L.) Osbeck husks and the pattern of the major constituent. Materials and methods: For this, we distill the oil by hydrodistillation, identify the components by gas chromatography coupled with mass spectrometry (GC-MS), test the larvicidal activity against Aedes aegypti and calculate the lethal concentration at 50% (LC50) by the Reed-Muench method and the confidence interval by the Pizzi method for both oil and standard. Results: it showed that the oil consists mostly of limonene and showed larvicidal activity (LC50 of 199.01(± 2.10) μg·mL-1) greater than the lemonade standard (126.03 (± 2.09) μg·mL-1). Conclusion: Therefore, we conclude that distilled oil has the potential to replace chemical larvicides.

Assessment of the phytochemical, antioxidant and larvicidal activity of essential oil extracted from Simpleleaf Chastetree [vitex trifolia] leaves obtained from Ganye Local Government, Adamawa State-Nigeria

Studies on the essential oils for the phytochemical, larvicidal, antioxidant and antimicrobial properties of vitex trifolia fresh leaves obtained from Ganye Local Government, Adamawa state, Nigeria were carried out. Out of the compounds with different concentrations obtained from the analysis, major constituents include caryophyllene, 4-methylidene-1-propan-2-ylbicyclo [3,1,0] hexane[sabinene], 2,6,6-trimethylbicyclo [3,1,1] hept-2-ene, naphthalene, 1,2,3,4,4a,5,6,8a-octahydro-7-methyl-4-methylene-1-[1–methylethyl] [1α,4αβ,8aα], [1Z,4Z,8Z]-2,6,6,9-tetramethylcycloundeca-1,4,8-triene, Naphtalene,1,2,3,5,6,8a-hexahydro-4,7-dimethyl-1-[1-methylethyl], [1S-cis]-, Naphthalene, decahydro-4a-methyl-1-methylene-7-[1-methylethenyl], terbenthene, 2-p-menthadiene and trans sabinene hydroxide which contains 22.80%, 27.40%, 7.70%, 5.23%, 4.90%, 3.52%, 4.14%, 3.52%, 3.52% and 1.03% respectively. In addition to the essential oils obtained, the results also depicted the presence of phytochemicals varying from terpenoids, glycoside, flavonoids and tannins. The displayed activity profile for the scavenging ability and high larvicidal activity of the essential oil from the sample depends on its concentration.

Chemical profile and larvicidal activity of essential oil obtained from the leaves of Plectranthus amboinicus (Lour.) Spreng

This study aimed to determine the chemical constituents and larvicidal activity of the essential oil of Plectranthus amboinicus (Lour.) Spreng against larvae of the Aedes aegypti mosquito. The essential oil (EO) was extracted by hydrodistillation at 100 ° C for 3 hours. The chemical composition was obtained by Gas Chromatography coupled to Mass Spectrometry (GC / MS). To assess larvicidal activity, Aedes aegypti larvae were subjected to EO solutions in concentrations of 10-100 mg L-1, where larval mortality was assessed and the LC50 was determined using the Probit method. The main chemical constituent found in the EO was carvacrol, which is considered to be very promising for pharmaceutical synthesis. The EO showed larvicidal activity with an LC50 of 28.52 mg L-1. According to the results found, it was possible to evaluate that the analyzed EO is composed of substances that have an efficient larvicidal effect against Aedes aegypti, thus encouraging its potential for application.

Larvicidal activities of essential oils of indigenous medicinal plants, Mentha pulegium L., Satureja hortensis L., and Thymus vulgaris L. against malaria vector, Anopheles stephensi

According to World Health Organization report, malaria is the main important arthropod-borne disease in the World . There is several chemical control of mosquito. Due to resistant of vectors to different insecticides, this research was aim to evaluate the larvicidal activities of three native plants, Mentha pulegium L., Satureja hortensis L., and Thymus vulgaris L. against 3th-4th instar larvae of Anopheles stephensi.Medicinal plants were collected from different localities in East Azerbaijan province, Iran. The plant samples were dried in shaded place and the chopped plants were hydro-distilled in a Clevenger-type apparatus for 2–4 h and the EOs dried over anhydrous sodium sulfate. The EOs was maintained in the dark sealed vials at 4 °C until conduction of the larvicidal tests. The larvicidal tests were carried out based on the guideline of WHO.The values of LC50 of EOs of Mentha pulegiumL., Satureja hortensis L, and Thymus vulgaris L. were 40.1324, 34.1527, 53.1063 ppm respectively . The LC90 of EOs of Mentha pulegium L., Satureja hortensis L., and Thymus vulgaris L. were 122.1340,98.9910,96.4527 respectively. Satureja hortensis L. had the lowest LC50 and the Thymus vulgaris the highest one.More efforts are recommended for trade formulation, semi-field and field evaluations of EOs are strongly recommended at the malarious area, southern Iran.

Extraction, Characterization and Larvicidal Activity of Essential Oil and Hydrosol from Sida acuta Burm. f. Leaves Grown in Nigeria

Extraction, Characterization and Larvicidal Activity of Essential Oil and Hydrosol from Sida acuta Burm. f. Leaves Grown in Nigeria

Chemical composition and larvicidal activity of essential oils from Zingiber montanum (J. Koenig) Link ex. A. Dietr. against three mosquito vectors

The chemical composition and larvicidal activity of essential oils derived from the leaves and rhizomes of Zingiber montanum (J. Koenig) Link ex. A. Dietr. were reported. The main compounds in the leaf oil were -pinene (13.8%), -phellandrene (11.3%) and -pinene (7.3%) while the rhizome oil was dominated by sabinene (41.1%), terpinen-4-ol (22.7%) and (E)-nerolidol (14.3%). The minimum lethal concentration (larvicidal activity) LC50 of the rhizome oil at 24 h against Aedes albopictus was 35.17 μg/mL, while LC50 values of 32.20 μg/mL and 31.12 μg/mL were obtained against Aedes aegypti and Culex quinquefasciatus respectively. At 48 h the oil displayed larvicidal action with LC50 values of 23.18 μg/mL, 25.58 μg/mL and 18.99 μg/mL respectively towards Ae. albopictus, Ae. Aegypti and Cx. quinquefasciatus. The leaf oil did not exhibit significant mortality and larvicidal action. The results indicate the potential of rhizome essential oil of Z. montanum as a source of larvicidal agent.