Assessment of thiamethoxam effects on honey quality parameters in agricultural landscapes

Abstract

Honey bees (Apis mellifera) are vital pollinators in agricultural and natural ecosystems, and honey is an important natural product whose quality can reflect environmental conditions. The widespread use of neonicotinoid insecticides, particularly thiamethoxam, has raised concerns regarding their indirect effects on hive products. This study evaluated the effect of thiamethoxam exposure on selected physical properties of honey under field conditions. The experiment was conducted at Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India, during two consecutive mustard crop seasons (2022-23 and 2023-24). Honey samples were collected from A. mellifera colonies foraging in thiamethoxam-treated and untreated control plots. Physical parameters including pH, color (optical density at 560 nm), electrical conductivity, moisture content, and ash content were analyzed using standard analytical methods. Honey from thiamethoxam-treated plots consistently showed slightly higher pH values, darker color, and increased electrical conductivity compared to control samples in both seasons. Moisture and ash contents exhibited minor seasonal variations between treatments, though all values remained within acceptable quality standards. Greater variability in physical parameters was observed in treated honey, suggesting indirect effects of thiamethoxam mediated through plant-nectar-bee interactions.