Original paper
Phenolic monoterpene-rich essential oils from Apiaceae and Lamiaceae species: insecticidal activity and safety evaluation on non-target earthworms
Pavela, Roman; Morshedloo, Mohammad Reza; Mumivand, Hasan; Khorsand, Ghazaleh Jafari; Karami, Akbar; Maggi, Filippo; Desneux, Nicolas; Benelli, Giovanni
Entomologia Generalis Volume 40 Number 4 (2020), p. 421 - 435
published: Dec 17, 2020
published online: Nov 12, 2020
manuscript accepted: Sep 22, 2020
final revised version received: Sep 16, 2020
manuscript revision requested: Sep 14, 2020
manuscript received: Jul 3, 2020
DOI: 10.1127/entomologia/2020/1131
ArtNo. ESP146004004008, Price: 29.00 €
Abstract
The genera Oliveria (Apiaceae), Thymus and Satureja (Lamiaceae) encompass important medicinal and aromatic plants of Iran, which contains noteworthy amounts of essential oils (EOs) that are worthy of exploitation on an industrial level, including pesticide formulation development. In this study, the efficacy of five EOs obtained from O. decumbens, T. daenensis, S. sahendica, S. khuzistanica and S. rechingeri, was evaluated against three insects of economic relevance, the mosquito Culex quiquefasciatus, the housefly Musca domestica, and the moth Spodoptera littoralis. Potential non-target effects of these EOs were assessed on earthworms, Eisenia fetida. The chemical composition of the five EOs was determined by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). EOs from O. decumbens, T. daenensis, S. khuzistanica and S. rechingeri were characterized by oxygenated monoterpenes (70.3, 91.6, 89.7 and 89.4%, respectively), whereas the EO from S. sahendica was dominated by monoterpene hydrocarbons (63.3%) followed by oxygenated monoterpenes (35.3%). In all cases, the biogenetically related thymol (0.3–36.7%), carvacrol (1.3–89.6%), p-cymene (2.1–13.7%) and γ-terpinene (1.5–41.3%) were found as the characteristic volatile compounds of the five EOs, with high quantitative variation according to the species considered. The five EOs exhibited high toxicity on the three target insects, with LC50/LD50 values in the range of 16.2–29.3 µg mL-1, 18.1–48.1 µg adult-1 and 7.4–23.1 µg larva-1 on C. quinquefasciatus, M. domestica and S. littoralis, respectively. Toxicity of the five EOs on non-target soil invertebrates was minimal, leading to no or very low (5.0–7.5%) mortality on E. fetida when tested at the concentration of 200 mg kg-1, at variance with the positive control α-cypermetrin, which caused 100% mortality at 0.1 mg kg-1 of soil. Overall, our study discloses new opportunities to farmers growing these Iranian endemic plants, shedding light on the potential of these EOs to formulate effective and eco-friendly insecticides.
Keywords
Culex quinquefasciatus • Musca domestica • Spodoptera littoralis • essential oils • toxicity • eco-friendly insecticides