Peroxidation and unsaturation coefficients as biomarkers of environmental micro-exposure to molluscicides in Helix pomatia L.

This study was a follow-up of a previous study that investigated a set of selected fatty acids (FAs; 12 of 56 pools) in Helix pomatia L. as biomarkers of chemical stress induced by applying micro-doses of molluscicides. Here, the potential of rarely used peroxidation (PI) and unsaturation (UI) coefficients were tested as biomarkers. These indices were calculated based on the FA profiles of foot and hepatopancreas tissues of H. pomatia L. Snails were treated with three molluscicides: metaldehyde, methiocarb, and potassium chloride, in three doses each (5, 10, or 15 µl, 0.01% w/v concentration), for 12 weeks, under laboratory conditions. Correlations were evaluated between frequently used oxidation status indicators (catalase, glutathione peroxidase, selenium-dependent peroxidase, superoxide dismutase, glutathione transferase, glutathione reductase, glutathione, carbonyl protein, and thiobarbituric acid reactive substances, in the form of MDA) and UI and PI ratios. These results confirmed that fatty acids could be directly used as biomarkers of exposure and oxidative physiological status in snails. Moreover, the UI and PI, calculated based on FAs, clearly reflected the current oxidation status in snails. These indices changed with the application of micro-doses of molluscicides. In conclusion, these indices could serve as sensitive biomarkers of chemical stress in snails.

Larval morphology of selected Quedius Stephens, 1829 (Coleoptera: Staphylinidae: Staphylinini) with comments on their subgeneric affiliation.

The study concerns the larval morphology of eight Quedius species from four subgenera: Distichalius, Microsaurus, Quedius, and Raphirus. Mature larvae of three species: Q. (Microsaurus) brevis, Q. (M.) cruentus, and Q. (M.) microps are newly described. The hitherto poorly known larvae of five species: Q. (Raphirus) boops, Q. (Distichalius) cinctus, Q. (s. str.) fuliginosus, Q. (s. str.) molochinus and Q. (M.) mesomelinus, are redescribed. Illustrations of structural features are provided. The combination of characters that allow for distinguishing the known mature larvae of Quedius from closely related genera within the subtribe Quediina is specified. Diagnostic larval morphological characters for each of the subgenera are proposed. The analysis of morphological features within the genus Quedius, with the application of the Multi-Variate Statistic Package (MVSP), showed high distinctiveness of the subgenus Quedius and low coherence among species within the subgenus Microsaurus. The intraspecific variation in the number of bifurcate setae and their spacing on fore tibiae of Q. cinctus is presented.