Honey bees are one of the most significant pollinators and contribute to thepollination
of various crops. The honey bee,Apis mellifera(Linnaeus, 1758), has uniquecharacteristics
that could be successfully used to improve biomonitoring approaches inassessing environmental
interactions. Three apiaries with different rates of honey beecolony losses were
included in the study—Dimovtsi, Plovdiv, and Krasnovo, Bulgaria.Male individuals (immature
and mature) were collected from five colonies for each ofthe three apiaries and studied
for histopathological changes in the gonads. The resultsconcerning the rate of honey
bee colony losses in the studied apiaries from 2022 and2023 showed honey bee losses
in the tested colonies due to queen problems, which werereported for Plovdiv, as well
as the death of honey bees or a reduction in their number to afew hundred bees in
the colony. The chemical analysis showed the presence of differentorganic substances,
such as Coumaphos, DEET (N, N-diethyl-M-toluamide), Fluvalinate,and Piperonyl-butoxide,
in the alive and dead honey bee samples and those of food stocks(wax, pollen, and
honey) within the hives. Among the sample types, those of the deadhoney bees contained
the greatest variety of pesticide residues, particularly in Plovdivand Dimovtsi, reinforcing
the link between pesticide exposure and honey bee mortality.The histopathological
alterations were mainly associated with the thinning of the coveringepithelium of
the seminiferous tubules and the detachment of the basement membrane ofthe seminiferous
tubules. The more severe histopathological lesion, necrosis, was observedin a higher
degree of expression in the drones from Plovdiv, indicating a higher pollutionlevel
in this region.
