Effect of Thymus vulgaris L. and Origanum vulgare L. essential oils on toxicity, food consumption, and biochemical properties of lesser mulberry pyralid Glyphodes pyloalis Walker (Lepidoptera: Pyralidae)

Abstract

The essential oils of Thymus vulgaris L. and Origanum vulgare L. were investigated for their toxicity and physiological aspects on the lesser mulberry pyralid Glyphodes pyloalis Walker in controlled condition (24±1°C, 75±5% RH and 16L : 8D). The leaf disc method was used to study acute toxicity, the effect of LC10, LC30, and LC50 on the feeding efficiency of 4th instar larva, and biochemical indices. The essential oil doses of LC10, LC30 and LC50 were estimated to be 0.107%, 0.188% and 0.279% for T. vulgaris, and 0.67%, 1.173% and 1.728% for O. vulgare, respectively. The results showed that T. vulgaris was more toxic than O. vulgare. The essential oil sublethal dose LC30 affected the nutritional indices of 4th instar larvae of G. pyloalis. The essential oils reduced total protein, carbohydrate, and lipid. Some concentrations of essential oils changed the activity level of α-amylase, protease, lipase, general esterases, and glutathione S-transferase (GST) but others showed no effect on these enzymes. It was concluded that the used essential oil concentrations were both toxic to G. pyloalis and showed irreversible effects on key metabolic processes, therefore, the used essential oil concentrations may be considered as alternatives to the classic pest control agents.

Effect of Artemisia annua L. essential oil on toxicity, enzyme activities, and energy reserves of cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

“…Proteases are important in digesting food and converting protein into amino acids needed for the body. Lipases are enzymes that hydrolyze the outer links of fat molecules (Yazdani et al 2014). In this study, lipase activity had no significant differences in the treated larvae in comparison with the control, but the LC 50 concentration of A. annua decreased the activity of this enzyme.…”

“…The oil phase was isolated from the obtained solution. Sodium sulfate was used for dehydration (Yazdani et al 2014).…”

The effect of thyme (Thymus caucasicus) ethanol extract on Varroa mite (Varroa destructor), an ectoparasite mite of Apis mellifera meda (Hym: Apidae)

“…Plants of the Meliaceae family were studied to find extracts that could play the role of repellents, antifeedants or insect growth regulators (Reed et al, 1982). Extracts of the Buckthorn (Melia azedarach) Elaeagnaceae, Peganum harmala L. Nitrariaceae, wild marjoram or oregano (Origanum vulgare L.) Labiatae, thyme (Thymus vulgaris), Lamiaceae, China berry (Melia azedarach) Meliaceae were studied to identify their insecticide effects on insects such as the red flour beetle (Tribolium castaneum) (Col: Tenebrionidae) and Noctuid leaf eater larvae (Spodoptera exigua), and to evaluate the antifeedant properties of those extracts on the Colorado potato beetle (Leptinotarsa decemlineata), aphids (Homoptera: Aphididae), and whiteflies (Homoptera: Aleurodidae) (Ventura, Ito, 2000;Szczepanik et al, 2012;Yazdani et al, 2014). Thymol, as one of the essential oils extracted from thyme, proved to play the role of the GABA (Gamma-aminobutyric acid) mimeting and modulating agent.…”

Pharmacological and Phytochemical Studies of Origanum Vulgare: A Review

“…Oregano is interrelated to the majo, body referred to as wild marjoram. Oregano has purple flowers and spade-shaped, olive color leaves [9]. It is a perennial, though it is grown-up as an twelve-monthly in colder climates, as it frequently does not live through the winter [10].…”