Soil contamination with permissible levels of lead negatively affects the community of plant-associated insects: A case of study with kale

• Published in: Environmental pollution (1987) 2022-07, Vol.304, p.119143-119143, Article 119143
• Main Authors: Morales-Silva, Tiago, Silva, Bruna C., Faria, Lucas D.B.
• Format: Article
• Language: English
• Subjects: Animals; Brassica; Ecosystem; Elemental defense; Heavy metals; Herbivorous insects; Insecta; Kale; Lead - toxicity; Natural enemies; Plants; Population density; Soil; Soil Pollutants - analysis; Soil Pollutants - toxicity
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.119143

This study investigated whether lead (Pb), at concentrations allowed for soil, affects the community of insects that live in the aerial part of plants. We evaluated the effect of Pb concentrations on accumulated species richness, composition, and abundance of different functional groups of insects. Kale plants were grown in soil experimentally contaminated with four concentrations of lead nitrate: 0 (control), 144 (T1), 360 (T2), and 600 (T3) mg/kg of soil. The experiment was conducted in an open greenhouse for the natural colonization of insects. Insects were collected twice using trap bags attached to the plant leaf and by direct removal. The concentration of Pb in the stem and leaf samples increased with the increased soil contamination, even showing values above the limit allowed by the legislation for this plant species. Control plants showed a higher richness of accumulated insect species. In addition, the treatments had an effect on the community composition, in which Diaeretiella rapae (primary parasitoid) was found as an indicator of the control + T1 treatments and the top species Pachyneuron sp. (parasitoid of predators) was associated with the control. The abundance of chewing and sucking herbivores, their respective parasitoids, predators, and parasitoids of predators were negatively affected. Hyperparasitoid abundance was not affected, but their accumulated species richness was. This study was innovative in demonstrating that soil contamination by different concentrations of a heavy metal (Pb) can negatively affect the community of plant-associated insects, even at concentrations allowed for soil, reflecting possible damage to the ecosystem. [Display omitted] •Permissible Pb concentrations for soils affect the plant-associated insect community.•Herbivores, primary and top parasitoids and predators show a reduced abundance.•Soil Pb concentrations lead to Pb levels in leaves above the permitted level.