Time-delayed effect of petroleum-derived products in soil and their bioremediation on plant - herbivore interaction

The aim of the study was to determine the time-delayed (after three years from the moment of soil pollution) effect of petroleum-derived products (PDPs) (petrol, diesel fuel and used engine oil) on the interaction between selected host plant (broad bean) and a herbivorous insect closely related to it (Sitona spp.). We assessed the condition of the plant exposed to pollutants (i.e. its growth and chemical composition), then we evaluated the attractiveness of the plant for both larvae and adults of the insect. The evaluation covered also the effect of bioremediation by using ZB-01 biopreparation. The results showed that after 3 years from soil contamination, engine oil and diesel fuel limited the feeding of adult sitona weevils while petrol caused increase in the attractiveness of plants for these insects. The PDPs negatively affected the growth of plants. The changes in element content depended on the type of pollutant. The biopreparation ZB-01 eliminated or reduced the differences caused by the presence of PDPs in the soil regarding the chemical composition of the host plant, and limited feeding by both the larvae and adult individuals of sitona weevils. The negative relationships between the contents of both some macroelements (Mg, S) and heavy metals (Zn, Ni), and feeding of imago of Sitona were observed. The obtained results indicate that PDPs remain for a long time in the environment and adversely affect not only the organisms directly exposed to the pollution – plants growing on polluted soil but also further links of the trophic chain, i.e. herbivores