Biological activities and gene expression of detoxifying enzymes in Tribolium castaneum induced by Moutan cortex essential oil

The present study aimed to analyze the chemical composition and fumigant toxicity of essential oils (EOs) isolated by hydrodistillation from Piper hancei Maxim. EOs extracted from the dry stems and leaves of P. hancei were analyzed by gas chromatography-mass spectrometry (GC-MS). The main compositions of the EOs were humulene (13.624 %), caryophyllene (13.319 %), nerolidol (12.507 %), naphthalene (8.525 %), ledol (6.694 %), caryophyllene oxide (6.404 %), and junenol (6.350 %). The fumigant toxicity of the EOs was tested in 7-14 day old adults of Tribolium castaneum. The LC50 of EOs and individual main compositions were calculated according to the mortality of insects at concentrations of 0, 16, 32, 64, 128, and 256 (μL/L air). The results showed that the EOs (LC50=322.52 (48 h) and 145.82 (72 h) (μL/L air)), caryophyllene (LC50=37.95 (48 h) and 26.53 (72 h) (μL/L air)), junenol (LC50=38.32 (48 h) and 20.33 (72 h) (μL/L air)), caryophyllene oxide (LC50=97.72 (48 h) and 65.22 (72 h) (μL/L air)), and humulene (LC50=104.50 (48 h) and 73.66 (72 h) (μL/L air)) have obvious fumigant activities against T. castaneum adults. The chemical composition of EOs from P. hancei was reported for the first time. The results indicated that the EOs of P. hancei had the potential to be developed as a natural insecticide for the control of T. castaneum adults.

Thymus quinquecostatus Celak. of the Lamiaceae family has a long history of dual use of medicine and food with high economic value, and has been proved to have good antioxidative, antimicrobial, and antidiabetic activities. Essential oil (EO) extracted from the aerial part of T. quinquecostatus was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC/MS) and GC. Totally 45 compounds were identified accounting for 98.5 % of the EO. The major constituents of the EO were linalool (52.003 %), borneol (10.911 %) and anethole (5.325 %). Fumigant, contact and repellent activity of T. quinquecostatus essential oil (EO) against Tribolium castaneum (Coleoptera: Tenebrionidae), Lasioderma Serricorne (Coleoptera: Anobiidae), Liposcelis bostrychophila (Psocoptera: Liposcelididae) were evaluated in this work. T. quinquecostatus EO and three major constituents showed varying degrees of insecticidal and repellent activities to three stored-product insects. Anethole stated the best fumigant and contact activity than others did to all three insect species. EO and compounds showed general repellent activity against three target insects. This work suggests that the EO of T. quinquecostatus has promising potential to be developed into botanical pesticides and repellents controlling pest damage in warehouses and grain stores.

Essential oils (EOs) derived from certain medicinal plants present a potential alternative to synthetic insecticides for managing stored-product insects. Two major insects, Tribolium castaneum (TC) Herbst (Coleoptera: Tenebrionidae) and Lasioderma serricorne (LS) (Coleoptera: Ptinidae), are key targets for EO control. Pastinaca sativa L. has medicinal and industrial uses and shows potential as a biopesticide. EOs were extracted from P. sativa aerial parts (A1) and fresh roots (R1-R3 obtained sequentially) via hydrodistillation. Gas chromatography-mass spectrometry (GC-MS) analysis showed 3-carene, 2,6-dimethyl-1,3,5,7-octatetraene, E,E-, and myristicin as dominant components in A1 EO, R1 EO and R2, R3 EOs. Four EOs exhibited both contact toxicity and repellent activity. R1-R3 EOs demonstrated strong efficacy compared to A1, showing the LD50 values: 8.25µL/adult for R1 EO against TC and 14.31µL/adult for R3 EO against LS. EO's repellent effects were comparable to N,N-diethyl-3-methylbenzamide (DEET) at the highest concentrations. As the concentration decreased, the repellent effect gradually turned into an attractant effect. Generally, four EOs exhibited stronger repellent effects against TC than LS. This research confirmed that P. sativa EOs possessed insecticidal potential and offered scientific guidance for its efficient extraction, demonstrating its promise as a novel eco-friendly insecticide.

The aim of this research was to determine the repellent and antimicrobial activities of the essential oil and hexanic extracts obtained from the leaves and fruits ofSchinus molle L. (Anacardiaceae). The composition of essential oils and hexanic extracts were analyzed by GC-MS. Oriental cockroach (Blatta orientalis L.) adults and nine bacterial strains were used for repellent and antimicrobial activity assays, respectively. The best antimicrobial activities were determined at 30 µg/ml dosage for Escherichia coli 0157:H7 and Bacillus cereus with leaf extracts. At all doses (176, 70 and 35 µg/cm2) the leaf essential oil showed not significant repellency than the positive control, DEET (N,N diethyl-m-toluamide), Hexanic extract of the leaf showed good repellency (83.33%) at the highest concentration (0.075 mg/L) against the oriental cockroach. The results indicated that the essential oil and hexanic extracts of S. molle showed potential in terms of antimicrobial and repellent activities. Key words: Antimicrobial, Blatta orientalis, essential oil, Schinus molle, repellent.

Purpose: To determine the insecticidal properties of essential oil from Mosla soochowensis aerial parts against two insect pests, Sitophilus zeamais and Tribolium castaneum.Methods: Hydro-distillation of M. soochowensis was used to extract the essential oil. Gas chromatography/mass spectrometry (GC/MS) analysis was performed, and the contact (topical application) and fumigant toxicity (sealed space) of the essential oil were evaluated.Results: Thirty-nine chemical compounds were identified by GC-MS analysis of M. soochowensis essential oil. The major components are β-caryophyllene (12.82 %), spatulenol (6.34 %), β-eudesmol (6.26 %), carvone (6.12 %), α-thujone (5.12 %), γ-eudesmol (4.86 %), α-cedrol (4.23 %), and α- caryophyllene (4.04 %). The plant essential oil exerted contact toxicity against adults of S. zeamais and T. castaneum (median lethal concentration (LC50), 25.45 and 10.23 μg/adult, respectively). Moreover, the essential oil exhibited pronounced fumigant toxicity towards adults of both species (LC50 12.19 and 10.26 mg/L air, respectively).Conclusion: These results show that M. soochowensis essential oil can be used in development of safer and more natural and effective fumigants/insecticides for stored products.Keywords: Mosla soochowensis, Contact toxicity, Sitophilus zeamais, Fumigant, Insecticide, Essential oil, Tribolium castaneum

Geranium (Pelargonium graveolens) is an economic plant in Egypt that can resist insect infections, which may be related to its oils. Three types of geranium essential oils (geranium oil, geranium absolute and geranium stripping oil) were extracted with three different methods (steam distillation, solvent extraction, and hydrodistillation respectively). The three types of crude essential oils, three natural components (linalool, citronellol, and geraniol), and synthetic counterparts of two of these components (linalool and citronellol) were evaluated against Tribolium castaneum and Rhyzopertha dominica adults using two bioassays evaluating their repellency and fumigation effects. The tree types of crude geranium essential oils were analysed by gas chromatography/mass spectrometry (GC-MS). Chromatographic analysis of the geranium essential oils demonstrated that citronellol is the main constituent, accounting 29.70, 31.80 and 18.30% of geranium oil, geranium stripping oil and geranium absolute, respectively. Geranium absolute had the highest repellent activity against T. castaneum. In contrast, geranium stripping oil had the greatest repellency against R. dominica. Furthermore, natural linalool had the strongest fumigant effect on T. castaneum among the oil components, while citronellol had the strongest effect on R. dominica, and the oil components had stronger fumigant effects than the crude geranium oils. The fumigation activity showed the same trend as repellency against the two tested insects. Based on the LC50, the oil components having a stronger effect than the crude geranium oils. Finally, T. castaneum was more tolerant than R. dominica to all tested materials. The method of extraction effects on the chemical composition of essential oils produced from the same plant, all tested crude essential oils and its components (natural and synthetic) can be used as safe pesticide alternatives for stored product insects, geranium stripping oil is a new crude oil can increase the national income instead of losing it in waste water.

Storage pests influence food production and conservation worldwide. The common control measures for these pests involve the use of synthetic pesticides, but these pesticides are harmful to the environment and human health. Thus, biological insecticides can substitute or reduce dependence on synthetic insecticides. This work aimed to study the insecticidal activities of essential oils (EOs) from leaves, fruits and stems of Melicope pteleifolia and their main compound against three kinds of pests, Tribolium castaneum, Lasioderma serricorne and Liposcelis bostrychophila. The Gas Chromatography - Mass Spectrometry (GC-MS) detection showed that β-cis-ocimene was the major compound in EOs from leaves and fruits of M. pteleifolia (26.96, and 65.99%, respectively). The main compound of stems EO is origanene (77.00%). In the fumigation test, EO of fruits and β-cis-ocimene were toxic to L. serricorne, and β-cis-ocimene was toxic to T. castaneum. The EOs and β-cis-ocimene had significant contact toxicity and repellent effect on these three species of pests. The results indicated that M. pteleifolia EOs are potential biological insecticides for controlling storage pests.

Chemical composition of essential oils extracted from six Murraya species and their repellent activity against Tribolium castaneum

The essential oil was obtained from the aerial parts of Pogostemon cablin by hydrodistillation. The chemical compounds of P. cablin essential oil were analyzed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. Eight compounds were totally identified and accounted for 92.4% of the oil. Patchoulol was the major component (51.1%), followed by phloroacetophenone (23.5%) and β-patchoulene (7.3%). The essential oil and its two major compounds patchoulol and phloroacetophenone were evaluated for their contact and repellent activities against Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila. Results of bioassays indicated that the essential oil and patchoulol had great contact toxicity against three species of insects. Meanwhile, the essential oil and patchoulol showed great repellent activities against T. castaneum and L. bostrychophila but were mildly repellent to L. serricorne. Phloroacetophenone exhibited neither contact nor repellent activity against any of these target insects. This work emphasized the promising potential of P. cablin to control insect pests during storage.

Insecticidal and repellent activity of three Satureja species against adult red flour beetles, Tribolium castaneum (Coleoptera: Tenebrionidae)

Repellency activity of vanillyl butyl ether is mediated by transient receptor potential vanilloid channels in the red flour beetle, Tribolium castaneum (Herbst)

The chemical composition of the essential oil of Etlingera yunnanensis rhizomes and its contact and repellent activities against Tribolium castaneum (Herbst) and Liposcelis bostrychophila (Badonnel) were investigated. The essential oil obtained from E. yunnanensis rhizomes with hydrodistillation was performed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. The main components of the essential oil were identified to be estragole (65.2%), β-caryophyllene (6.4%), 1,8-cineole (6.4%), limonene (5.2%), and α-pinene (2.4%). It was found that the essential oil of E. yunnanensis rhizomes possessed contact toxicity against T. castaneum and L. bostrychophila (LD50 = 23.33 μg/adult and LD50 = 47.38 μg/cm2, respectively). Estragole, 1,8-cineole, and limonene exhibited stronger contact toxicity (LD50 values of 20.41, 18.86, and 13.40 μg/adult, respectively) than β-caryophyllene (LD50 = 41.72 μg/adult) against T. castaneum adults. Estragole possessed stronger contact toxicity (LD50 = 30.22 µg/cm2) than β-caryophyllene, 1,8-cineole, and limonene (LD50 values of 74.11, 321.20, and 239.62 μg/adult, respectively) against L. bostrychophila adults. Repellency of the crude oil was also evaluated. The essential oil and constituents possessed strong repellent activity against T. castaneum adults. The four individual constituents showed weaker repellent activity than the essential oil against L. bostrychophila adults. The results indicated that the essential oil of E. yunnanensis rhizomes and the individual constituents had the potential to be developed as a natural insecticide and repellent for the control of T. castaneum and L. bostrychophila.

Essential oil (EO) of Artemisia maritima plants growing naturally in the cold desert region has been extracted by hydro distillation at different growth stages during 2015-16. The constituents of the EO have been characterized by gas chromatography (GC) and GC-mass spectrometry. Nineteen compounds were identified. EO content and composition vary throughout the vegetation period of the plant. The best time for higher EO content (0.45±0.15 %) is August, while for higher 1,8-cineole (59.24±1.63 %) is during October. EO of A. maritima was characterized by high content of 1,8-cineole, bornyl acetate, terpinen-4-ol, camphor, sabinene and germacrene D which varied from 90.54±7.76 to 92.41±6.50 % of the total oil content. The EO of A. maritima was evaluated for their acaricidal activity against two-spotted spider mite (Tetranychus urticae) (Acarina: Tetranychidae). EO reported excellent fumigant activity against T. urticae with LC50 value of 323.86, 27.05, 15.48 and 12.15 mgL-1 after 1, 2, 3 and 4 h of treatment, respectively as compared to positive control i.e. Propargite 57 % EC (755.72 mgL-1). In repellent activity, 10000 mgL-1 showed significantly higher repellency (95.83±1.67 %) to adult T. urticae and was at par with positive control i.e. Azadirachtin 0.15 % EC (96.67±3.33 %) and 8000 mgL-1 (91.67±2.20 %) as compared to other concentrations studied.

The present investigation was aimed to analyse the chemical composition of essential oil isolated from Heracleum persicum Desf. ex Fischer and assess its lethal and sub-lethal effects against Tribolium castaneum (Herbst). Essential oil from hydro-distilled seeds of H. persicum was analyzed by gas chromatography-mass spectrometry (GC-MS), and hexyl butyrate (50.58%), octyl acetate (9.80%) and hexyl hexanoate (8.75%) were found as principal constituents. Repellent activity, contact and fumigant toxicity and antifeedant effects of this oil were assessed against the adults of T. castaneum. The essential oil strongly repelled T. castaneum adults even at the lowest concentration (0.035 μL cm-2). Complete repellency (100%) occurred when the highest concentration (0.212 μL cm-2) was applied for 8 h. T. castaneum was very susceptible to H. persicum oil at both contact and fumigant bioassays. In the fumigant toxicity, essential oil killed the larvae, pupae and adults and significantly decreased larvae emerged from treated eggs. LC10 to LC40 values of fumigation adult’s bioassay as sub-lethal concentrations were used to evaluate the antifeedant effects. H. persicum essential oil has significant antifeedant effects on T. castaneum adults and decrease of feeding happened when oil concentrations increased. The results of the present study indicate that essential oil of H. persicum, with wide bio-effects on T. castaneum, is a source of biologically active agents which may potentially prove to be efficient insecticides.

Chemical Composition and Insecticidal Properties of Essential Oil Obtained from Artemesia songarica Schrenk