Acaricidal property of the essential oil from Lippia gracilis against Tetranychus urticae and a natural enemy, Neoseiulus californicus, under greenhouse conditions

Abstract

The essential oil from the leaves of Lippia gracilis was investigated for fumigant and residual activity against Tetranychus urticae (Acari: Tetranychidae) and Neoseiulus californicus (Acari: Phytoseiidae). The results were compared to eugenol, Ortus and Azamax, as positive controls. Gas chromatography (GC) and GC/mass spectrometry analysis enabled the identification of 28 compounds, accounting for 99.1 ± 0.6% of the essential oil. The major constituents were carvacrol (61%), p-cymene (11%) and thymol (11%). Mites were more susceptible to the oil in fumigant tests than in residual tests. Among the components, thymol and β-caryophyllene had the greatest fumigant and residual toxicity against T. urticae, respectively. The role of selected constituents (carvacrol, p-cymene, thymol, limonene, β-pinene, 1,8-cineole, terpinolene and β-caryophyllene) in the acaricidal properties of the L. gracilis essential oil is also discussed. Fumigant and residual effects of Lippia oil were more selective than eugenol with regard to a natural enemy of T. urticae, Neoseiulus californicus. Experiments under greenhouse conditions demonstrated greater toxicity of the Lippia oil in comparison to the positive control at 24, 48 and 72 h after treatment. The results suggest that Lippia oil is a good candidate for the formulation of a botanical acaricide for the integrated management of T. urticae.

Acaricidal properties of essential oils from agro‐industrial waste products from citric fruit against Tetranychus urticae

“…The fumigant action and residual contact effect of selected chemical constituents of EOs, including some of the selected compounds analysed in the present study, on T. urticae have previously been investigated. Born et al (2018) found the same susceptibility of T. urticae to terpinolene and β-pinene by fumigation and residual contact as that reported in the present study. Badawy, Abdelgaleil, Mahmoud, and Marei, (2018) found the same level of toxicity for limonene by fumigation (LC 50 = 10.35 mg/L air) and residual contact (LC 50 = 50.95 mg/L) compared to the present findings.…”

“…For instance, the oils from Piper aduncum (LC 50 = 7.17 μl/ml ≅ 7.00 mg/ml)(Araújo et al, 2012) and oils from the green (LC 50 = 7.44 μl/ml) and ripe (LC 50 = 7.29 μl/ml) fruits of Schinus terebinthifolius (Nascimento, Camara, & Moraes, 2012) were more toxic than the four Citrus oils investigated herein, whereas the oil from Vitex agnus-castus(Neves & Camara, 2016) was less toxic. In other studies using the same population of T. urticae, the oils from Lippia gracilis (LC 50 = 29.70 μl/ml)(Born, da Camara, de Melo, & de Moraes, 2018) and Aristolochia trilobata (LC 50 = 62.54 mg/ml) (de Melo, Camara, Silva Lima, Moraes,…”

The application of essential oils as a next-generation of pesticides: recent developments and future perspectives

“…as acaricidal agent against the plantfeeding mite Tetranychus urticae Koch., showing toxicity against the eggs and adults, as well as oviposition deterrent and repellent activity. Good results (LC 50 = 0.06 mL/L air) were also obtained by Born et al [109] against the same mite species, using L. gracilis EO; the results also proved a high selectivity towards the tested mite, compared with its natural enemy, Neoseiulus californicus. Similar results were also obtained by Mahmoud et al [110] and Ribeiro et al [111].…”

New sources of botanical acaricides from species of Croton with potential use in the integrated management of Tetranychus urticae

“…Toxicity by residual contact of the chemical constituents found in essential oils against T. urticae has been investigated, including the same compounds analyzed in the present study, such as ρ-cymene, βcaryophyllene, β-pinene, α-pinene, 1,8-cineole, camphor, bicyclogermacrene and eugenol (Attia et al, 2012;Araújo et al, 2012;Moraes et al, 2017;de Melo et al, 2018;Hong et al, 2018;Born et al, 2018;Cao et al, 2019;Abdelgaleil et al, 2019;). However, this is the first report of the acaricidal activity against this pest of the constituents (E)-anethole, methyl eugenol, spathulenol, caryophyllene oxide, eugenyl acetate, α-phellandrene and βphellandrene.…”