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The volatile metabolites of Salvia sclarea, Rosmarinus officinalis, Thymus serpyllum, Mentha spicata, Melissa officinalis, Origanum majorana, Mentha piperita, Ocimum basilicum and Lavandula angustifolia were determined by gas chromatography–mass spectrometry. The vapor insecticidal properties of the analyzed essential oils and their compounds were screened using Reticulitermes dabieshanensis workers. The most effective oils were S. sclarea (major constituent linalyl acetate, 65.93%), R. officinalis (1,8-cineole, 45.56%), T. serpyllum (thymol, 33.59%), M. spicata (carvone, 58.68%), M. officinalis (citronellal, 36.99%), O. majorana (1,8-cineole, 62.29%), M. piperita (menthol, 46.04%), O. basilicum (eugenol, 71.08%) and L. angustifolia (linalool, 39.58%), which exhibited LC50 values ranging from 0.036 to 1.670 μL/L. The lowest LC50 values were recorded for eugenol (0.060 μL/L), followed by thymol (0.062 μL/L), carvone (0.074 μL/L), menthol (0.242 μL/L), linalool (0.250 μL/L), citronellal (0.330 μL/L), linalyl acetate (0.712 μL/L) and 1,8-cineole (1.478 μL/L). The increased activity of esterases (ESTs) and glutathione S-transferase (GST) were observed but only alongside the decreased activity of acetylcholinesterase (AChE) in eight main components. Our results indicate that S. sclarea, R. officinalis, T. serpyllum, M. spicata, M. officinalis, O. marjorana, M. piperita, O. basilicum and L. angustifolia essential oils (EOs) and their compounds, linalyl acetate, 1,8-cineole, thymol, carvone, citronellal, menthol, eugenol and linalool could be developed as control agents against termites. [ABSTRACT FROM AUTHOR]

The citrus red mite, Panonychus citri (McGregor), is an important pest of citrus in China, where pesticides are commonly used in citrus orchards. In order to reduce the use of chemical pesticides against P. citri and the development of resistance, the screening of biological control agents has attracted the attention of students. In this study, seven plant essential oils with high toxicity were selected from 40 plant essential oils by the leaf-dip bioassay, including plant essential oils of lemongrass, patchouli, juniper berry, sage, clove, frankincense, and citrus. The LC50 after 72 h treatment were 3.198 μL/mL, 8.312 μL/mL, 3.244 μL/mL, 6.701 μL/mL, 8.350 μL/mL, 21.953 μL/mL, and 8.788 μL/mL, respectively. According to the LT50, the essential oils' acute toxicity to P. citri from high to low were lemongrass, juniper berry, patchouli, citrus, sage, vetiver, and frankincense essential oils. In general, lemongrass and juniper berry essential oils have the best acaricidal effect and have high application value for the biological control of P. citri, which provides a basis for the development of botanical acaricides. [ABSTRACT FROM AUTHOR]

Cymbopogon citratus, essential oil, citral, walking and gripping behavior, chitin structure, Reticulitermes flaviceps 10.1002/ps.1927 50 Caballero-Gallardo K., Olivero-Verbel J., Stashenko E.E. Repellency and toxicity of essential oils from Cymbopogon martinii, Cymbopogon flexuosus and Lippia origanoides cultivated in Colombia against Tribolium castaneum. Oil Res. 2018; 30: 40-46. 10.1080/10412905.2017.1375035 10 Gao S., Liu G., Li J., Chen J., Li L., Li Z., Zhang X., Zhang S., Thorne R.F., Zhang S. Antimicrobial activity of Lemongrass essential oil (Cymbopogon flexuosus) and its active component citral against dual-species biofilms of Staphylococcus aureus and Candida species. Keywords: Reticulitermes flaviceps; Cymbopogon citratus; essential oil; citral; walking and gripping behavior; chitin structure EN Reticulitermes flaviceps Cymbopogon citratus essential oil citral walking and gripping behavior chitin structure N.PAG N.PAG 15 09/27/22 20220901 NES 220901 1. [Extracted from the article]

Biodegradation of wood by fungi and termites is recognized as one of the most serious problems for wooden structures. In this study, we analyzed the antitermitic and antifungal activities of flower buds essential oil from Syzygium aromaticum and its dominant constituents. Essential oil components were analyzed by gas chromatography and the major compound of essential oil was eugenol (90.6%). The results demonstrated that at the dosage of 50 μg/g, clove essential oil had 100% mortality to Reticulitermes chinensis after testing for 5 d. Furthermore, we found eugenol killed all termites after testing for 3 d, with an LC 50 value of 12.1 μg/g. Meanwhile, we also found clove essential oil and eugenol displayed activity against three fungi, Trametes hirsuta , Schizphylhls commne , and Pycnoporus sanguineus . We found eugenol was principal antifungal constituent of clove oil. The IC 50 values of eugenol against T. hirsuta , S. commne , and P. sanguineus were 83.6, 116.1, and 102.4 μg/mL, respectively. In addition, comparisons of the termite mortality and antifungal indices of eugenol and its congeners proved that eugenol exhibited the strongest antitermitic and antifungal activities. The clove oil and eugenol have potential for the development of natural wood preservatives. [ABSTRACT FROM AUTHOR]