ASSESSMENT OF ACUTE AND CHRONIC TOXICITY OF NANOAQUACHELATES IN HONEY BEES (APIS MELLIFERA) IN LABORATORY CONDITIONS

Abstract

Correcting the micronutrient status of honey bees (Apis mellifera L.) is regarded as a promising way to support colony health; however, any new preparation that may enter the bee organism first requires a thorough safety evaluation. The aim of this study was to establish the nature of the effect of an experimental nanoaquachelate preparation based on Zn, Cu, Mn and Co on honey bee viability under acute and chronic oral exposure. Acute oral toxicity was assessed according to OECD Test Guideline No. 213 (6-8 November 2023): bees received single doses of 0.01, 0.05 and 0.10 mL/L in 50% sucrose solution, and mortality was recorded after 24 and 48 hours. The chronic assay followed OECD Test Guideline No. 245 (6-15 November 2023): for 10 days bees continuously consumed the preparation in feed at concentrations of 0.01, 0.025, 0.10, 0.50 and 1.0 mL/L. In the acute assay, mortality remained low across all dose groups - 0.00, 6.06 and 8.12% at 0.01, 0.05 and 0.10 mL/L, respectively, versus 2.08% in the control; none of the differences was statistically significant, and the LD50 exceeded 0.10 mL/L, corresponding to the low acute risk category. The chronic assay produced an unexpected yet telling result: in all five treatment groups mortality (6.3-31.6%) was lower than in the control group kept on a pure sucrose diet (46.9%). The protective effect of the preparation reached 86.6% at 0.50 mL/L and 78.9% at 1.0 mL/L. The study covered 299 bees distributed across 30 cages, and statistical analysis was carried out using Fisher’s exact test and probit regression in R. Thus, the preparation showed neither acute nor chronic toxicity to honey bees and, moreover, exerted a pronounced positive effect on their survival under a nutritionally poor diet. This confirms the safety of its use in beekeeping and points to its potential as a feed supplement for supporting honey bee colony health.