Currently, scientists are focused on developing new tools to control insect populations, including secondary plant metabolites that show promise for use in plant protection. Secondary plant metabolites cause toxic effects that can be observed at both lethal and sublethal levels, but the most important effect is repellence. These compounds can affect insects at all levels of biological organisation, but their action generally disturbs cellular and physiological processes.

Tombac produces various substances that affect insects belonging to most orders, particularly herbivorous insects and other pests. Many compounds possess insecticidal properties, but they are also classified as molluscides, acaricides, nematocides, fungicides and bactericides. Preliminary investigation of the effects of bio-oil compounds from whole plant extracts of Tombac were carried out on the beetle Leptinotarsa decemlineata, bacterias Streptomyces scabies and Clavibacter michiganensis, and the fungus Pythium ultimum. Testing of the effect of different crude extract on bacterias (Streptomyces scabies and Clavibacter michiganensis) isolates indicates that the methanol extract is the most bioactive. The test showed that the bioactivities of the crude extracts of the various parts of the Tombac were dependent and the whole plant was the most bioactive. The ethyl acetate fraction of the methanol extract of the whole plant of Tombac has been shown in this work to contain phytochemicals that have shown remarkable repellent activities. The bioactivities against Streptomyces scabies and Clavibacter michiganensis tested organisms were due to the combined effects of the compounds. Families of terpenoids, flavonoids, alkaloids, saponin, and steroids that were detected in the extracts were identified by GC-MS. The various classes of phytochemicals in the Tombac plant provided the antimicrobial potency of the plant. Only a small percentage of insect species are pests. However, pest species cause significant losses in agricultural and forest crops, and many are vectors of diseases.

In this paper, data will be presented on the sublethal and lethal toxicity caused by pure metabolites and crude extracts obtained from Tombac. Pure substances as well as water and/or alcohol extracts cause lethal and sublethal effects in insects, which is important from an economical point of view. The results of the study will also be discussed and their relevance to plant protection and management shown.