Effect of different feeding diets on the haemolymph of the newly emerged honeybee workers Apis mellifera L.

Abstract

Five diets were compared for measuring their effects on the differential haemocytes types of the newly emerged worker bees, and also on their haemolymph proteins, lipids and glucose content. As blood haemocytes cell play a role in defending honeybees against parasites and pathogens. Five groups of newly emerged worker bees were fed with one of the following diets in patty form with sugar: faba bean (Vicia faba) pollen, maize (Zea mays) pollen, date palm (Phoenix dactylifera) pollen, Egyptian clover (Trifolium alexandrinum) pollen and soya bean (Glycine max) flour (as pollen supplement). Differential haemocyte counts (DHC) were evaluated in smears of their haemolymph. The types of the haemocytes (prohaemocytes, plasmatocytes, oenocytoids, granulocytes, coagulocytes and binucleated cells) were recorded. The most abundant type was plasmtoycte cells (over 90%) followed by granulocyte cells and coagulocyte cells. These blood cells perform phagocytosis and encapsulation of foreign bodies in the honeybee body cavity. Feeding honeybees with these different diets caused significant differences between the haemocyte cells. The highest number of plasmatocyte cells recorded in bees which fed on maize pollen, while the lowest was found in bees fed on bean pollen. The highest protein content was found in the haemolymph of bees fed on date palm and the lowest was found in bees fed on bean pollen and the difference was non-significant. The difference in lipids content was non-significant in worker bees fed on these different diets. There was a significant difference in glucose content between bees fed on maize pollen and date palm pollen.

Effect of 1,3-1,6 β-Glucan on Natural and Experimental Deformed Wing Virus Infection in Newly Emerged Honeybees (Apis mellifera ligustica)

“…It can be speculated that the immune pathways’ activation triggered by 2% ß-glucan in presence of high viral load might adversely affect the host, as observed by Fronte et al (personal communication). In agreement with previous reports [39, 45], plasmatocytes were the most represented haemocyte subtype in our study population, except in group A 0.5 . This finding may support what previously reported by Sabcaliu et al [38] that described an increase of plasmatocytes in haemolymph of honeybees under stressful conditions.…”

“…Haemocyte subtype analysis for each individual honeybee was done by optic microscopy (magnification 40X and 100X) on 10 high power fields. Based on morphology, the haemocytes were classified as prohaemocytes, plasmatocytes, granulocytes and oenocytoids [38, 39]. …”

Bee bread increases honeybee haemolymph protein and promote better survival despite of causing higher Nosema ceranae abundance in honeybees

“…Dietary protein is a key nutritional component affecting insect immunity (Lee et al, 2006;Huang, 2012;Ponton et al, 2012), and influence physiological state and protein reserves in honeybees (Basualdo et al, 2013). In fact, the change from a natural to an artificial diet may affect cellular immunity (Szymaś and Ję druszuk, 2003;El Mohandes et al, 2010) and the levels of protein in haemolymph (De Jong et al, 2009;Morais et al, 2013). Although there is evidence that N. ceranae infection suppresses the honeybee immune response by reducing antimicrobial peptides (Antúnez et al, 2009), there is not enough background information about the relation between the natural and non-natural protein sources for honeybees and N. ceranae development.…”

Phenoloxidase activity and haemolymph cytology in honeybees challenged with a virus suspension (deformed wings virus DWV) or phosphate buffered suspension (PBS)

“…The PO cascade can be activated by some molecules such as lipopolysaccharides, β-glucans and peptidoglycans as observed also in recent studies focused on the effect of these molecules on both phenoloxidase activity and haemocytes populations (CHARLES & KILLIAN, 2015;MAZZEI et al, 2016;NAKHLEH, 2017; Millanta et al SHEEHAN, 2018). Prohaemocytes, plasmatocytes (round, oval, irregular), granulocytes and oenocytoids are all included in the term "haemocytes" (EL-MOHANDES et al, 2010;SABCALIU et al, 2010). Haemocytes are cell types responsible for the honeybees' defence against pathogens.…”

“…Cytologic examination was performed by optic microscopy (magnification 40X and 100X). Haemocytes were classified and quantified based on their morphology as prohaemocytes, plasmatocytes (round, oval, irregular), granulocytes and oenocytoids (EL-MOHANDES et al, 2010;SABCALIU et al, 2010).…”