Imidacloprid Induces Histopathological Damage in the Midgut, Ovary, and Spermathecal Stored Spermatozoa of Queens After Chronic Colony Exposure.

Bee colony health is declining as a result of several factors, including exposure to pesticides. The development and strength of honey bee colonies depend on the reproductive success of queen bees. Because flowers are sources of food for bees, foragers can accidentally collect and carry contaminated pollen and nectar to their hives; and this may compromise the longevity and the life span of individuals. Thus, the present study aimed to observe the action of imidacloprid in the midgut and ovaries of Apis mellifera queens, as well as the effects on sperm stored in their spermatheca. To this end, the apiary was divided into three experimental groups: control, commercial imidacloprid, and active ingredient imidacloprid. For toxicity assays, a sucrose solution containing 1 µg/L of imidacloprid was offered to the colonies for 42 days. A control group received only food in the same period. In both treatments with imidacloprid, the midgut of queens showed modifications in the external musculature and cellular alterations. Such changes could lead to the nonrecovery of the epithelium and subsequently malabsorption of nutrients. Moreover, the digestive cells of queen bees exposed to the commercial imidacloprid presented pyknotic nuclei, suggesting a cell death process. The main alterations observed in the ovaries of these reproductive bees treated with commercial imidacloprid were degeneration and resorption of the ovariole content, which probably affected their fertilization and colony development. There were no significant changes in the spermatozoa morphology for both treatments with imidacloprid, but this insecticide may interfere with the development and reproductive success of A. mellifera colonies because it affects the morphology and function of essential organs for the survival of queens. Environ Toxicol Chem 2022;41:1637-1648. SETAC.

Determination of the Ca, Mn, Mg and Fe in honey from multiple species of stingless bee produced in Brazil.

Stingless Bees (SB) honey is a product used for different purposes, and it is worth highlighting the presence of metallic species, which can have a nutritional or toxic effect, depending on the metal present and/or the amount ingested. Therefore, the objective of this work was to quickly determine Fe, Mn, Mg and Ca in SB honey, using slurry sampling and FAAS of 88 honey samples from different regions of Brazil. The concentrations varied from < LOD to 364 µg g-1 (Ca). The order for average concentration in the samples was Ca > Mg > Mn > Fe. Through the principal component analysis, it was verified that the SB honey analyzed in the present study has higher contents of the evaluated metals than the honey of the species Apis mellifera and SB honey from other Brazilian states. Theoretical calculation demonstrated that there is a little contribution of SB honey to human diet in relation to the metals, being more significative for Mn.

Performance of Africanized honeybee colonies settled by queens selected for different traits / Desenvolvimento de colônias de Apis mellifera formadas com rainhas selecionadas para diferentes características

We evaluated varroa infestation and the performance of Africanized honeybee colonies with queens selected for honey and royal jelly production, and also unselected queens, correlating with climatic variables. In Campo Alegre, Santa Catarina State, Brazil, the experiment I used 10 Langstroth hives and in Mafra, Santa Catarina State, Brazil, the experiment II was performed with 15 Schenk hives. A mapping in areas of sealed and unsealed brood, honey and pollen was carried out on days zero, 45 and 90 days after the introduction of the queen. In the experiment I, there was interaction between the type of queen selection and the evaluation period for areas of sealed brood, honey, and total stored food. The group selected for royal jelly production presented larger sealed brood area and smaller honey area at 90 days. Varroa infestation was lower (p 0.05) at 90 days. The type of queen selection and the evaluation period influenced the sealed brood area, the total brood and the total area occupied in the colony. The high relative humidity caused greater honey storage for the local group. The different groups of queens presented different behavior according to the environment in which they are settled.(AU)

Avaliaram-se a infestação por Varroa destructor e o desenvolvimento de colônias de A. mellifera com rainhas selecionadas para produção de mel, geleia real e rainhas não selecionadas, correlacionando-se com as variáveis climáticas. No experimento I, em Campo Alegre, Estado de Santa Catariana, utilizaram-se dez colmeias Langstroth e, no experimento II, em Mafra, Estado de Santa Catariana, utilizaram-se 15 colmeias Schenk. Procedeu-se ao mapeamento das áreas de cria aberta, operculada, mel e pólen, na data de introdução, aos 45 e 90 dias após a introdução das rainhas. No experimento I, houve interação entre o tipo de seleção da rainha e a época de avaliação para as áreas de cria operculada, mel e total de alimento. O grupo selecionado para geleia real apresentou maior área de cria operculada e menor área de mel aos 90 dias. A infestação por varroa foi menor (p < 0,05) aos 90 dias. No experimento II, não foi encontrado interação para as características avaliadas. As áreas de cria operculada, total de cria e total ocupada da colônia apresentaram efeito do tipo de seleção da rainha e época de avaliação. A alta umidade relativa do ar influenciou o maior armazenamento de mel para o grupo local. Os diferentes grupos de rainhas responderam diferentemente em função do ambiente onde estão inseridas.(AU)

Performance of Africanized honeybee colonies settled by queens selected for different traits / Desenvolvimento de colônias de Apis mellifera formadas com rainhas selecionadas para diferentes características

We evaluated varroa infestation and the performance of Africanized honeybee colonies with queens selected for honey and royal jelly production, and also unselected queens, correlating with climatic variables. In Campo Alegre, Santa Catarina State, Brazil, the experiment I used 10 Langstroth hives and in Mafra, Santa Catarina State, Brazil, the experiment II was performed with 15 Schenk hives. A mapping in areas of sealed and unsealed brood, honey and pollen was carried out on days zero, 45 and 90 days after the introduction of the queen. In the experiment I, there was interaction between the type of queen selection and the evaluation period for areas of sealed brood, honey, and total stored food. The group selected for royal jelly production presented larger sealed brood area and smaller honey area at 90 days. Varroa infestation was lower (p 0.05) at 90 days. The type of queen selection and the evaluation period influenced the sealed brood area, the total brood and the total area occupied in the colony. The high relative humidity caused greater honey storage for the local group. The different groups of queens presented different behavior according to the environment in which they are settled.

Avaliaram-se a infestação por Varroa destructor e o desenvolvimento de colônias de A. mellifera com rainhas selecionadas para produção de mel, geleia real e rainhas não selecionadas, correlacionando-se com as variáveis climáticas. No experimento I, em Campo Alegre, Estado de Santa Catariana, utilizaram-se dez colmeias Langstroth e, no experimento II, em Mafra, Estado de Santa Catariana, utilizaram-se 15 colmeias Schenk. Procedeu-se ao mapeamento das áreas de cria aberta, operculada, mel e pólen, na data de introdução, aos 45 e 90 dias após a introdução das rainhas. No experimento I, houve interação entre o tipo de seleção da rainha e a época de avaliação para as áreas de cria operculada, mel e total de alimento. O grupo selecionado para geleia real apresentou maior área de cria operculada e menor área de mel aos 90 dias. A infestação por varroa foi menor (p < 0,05) aos 90 dias. No experimento II, não foi encontrado interação para as características avaliadas. As áreas de cria operculada, total de cria e total ocupada da colônia apresentaram efeito do tipo de seleção da rainha e época de avaliação. A alta umidade relativa do ar influenciou o maior armazenamento de mel para o grupo local. Os diferentes grupos de rainhas responderam diferentemente em função do ambiente onde estão inseridas.