Assessment of thymol activity against pests of medical, veterinary and agricultural importance

УДК 619:615.285
DOI 10.33861/2071-8020-2024-5-32-37

Levchenko M. A.

Summary. The purpose of this work was to assess the degree of activity of thymol against insects and other pests of medical, veterinary and agricultural importance based on literary sources in comparison with substances of plant and synthetic origin. As a result of the work carried out, it was revealed that in tests of fumigant, contact and repellent activity against many pests among plant compounds, thymol in some cases was inferior to some of them, and in others it prevailed. In comparison with synthetic compounds, thymol also showed greater or lesser activity against pests. For example, when comparing LD50 of its activity with the pyrethroid insecticide bifentrin during contact action, it was found that it was about 90,000 times less toxic against adult male bed bugs Cimex lectularius L. In another comparison of fumigant action, against flies Stomoxys calcitrans (L.), thymol was also less active compared to dichlorophos and chlorpyrifos by more than 37,000 times. Compared to other compounds from the PHOS group, in direct contact, the activity of thymol was approximately 1000 times lower in relation to larvae of mosquitoes Aedes albopictus (Ae. albopictus), Aedes aegypti (Ae. aegypti) and Culex pipiens palles (Cx. p. pallens) of each species compared with temefos and fentione. In another case, when compared with oxamyl from the carbamate group, with respect to the root-affected nematode Pratylenchus penetrans parasitizing plants of a significant number of important crops worldwide, thymol activity was higher than that of this synthetic substance and it caused 100% death of these pests at a dose of 2 mg/ml in direct contact, whereas oxamyl in at the same doses, it caused death only in 65.62 ± 2.11% of pests.

Keywords: Thymol, insects, pests, monoterpenes, activity, effectiveness, insecticides, pesticides, fumigants, repellents, contact action.

Author affiliation: Levchenko Mikhail Alekseevich, Ph. D. in Veterinary Medicine, Head of the Laboratory of Veterinary Problems in Animal Husbandry of the All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology - Branch of the Federal Research Centre of the Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences; 2, Institutskaya st., Tyumen, 625041; phone: 8-3452-258558; e-mail: levchenko-m-a@mail.ru.