Effect of Propolis Oral Intake on Physiological Condition of Young Worker Honey Bees, Apis Mellifera L.

Abstract

A b s t r a c t Honey bees collect resin from various plant species and transform it into propolis that is incorporated into the nest. The role of resins in the bee health field is poorly understood. The aim was to evaluate the effects of forced consumption of propolis on the physiological condition and short-term survival of Apis mellifera worker bees. It was tested if the number of circulating hemocytes in hemolymph, the abdominal fat bodies and the hypopharyngeal glands development were affected by the feeding with propolis extracts in laboratory conditions during the warm and the cold seasons. Propolis added to sugar candy was consumed by workers for fourteen days without affecting the bee survival. The number of circulating hemocytes in hemolymph remained constant despite the differential diet during the experiment. However, the development of fat bodies and hypopharyngeal glands was altered by propolis ingestion. The abdominal fat body development in winter bees diminished after fourteen days of propolis consumption, while it increased in summer bees. The hypopharyngeal gland development decreased for the assayed period in workers from both seasons. Our results encourage us to continue exploring this research field and learn how long-term forced ingestion of a plant-derived compound, a non-nutritive substance, can modify physiological bee parameters. A broader understanding of the multiple roles of propolis in the health of the honey bee colonies could be obtained by studying the ways in which it is processed and metabolized and the effect that generates in another physiological responses.

Propolis Consumption Reduces Nosema ceranae Infection of European Honey Bees (Apis mellifera)

“…We evaluated for the first time if Nosema-infected bees are more attracted to a diet containing propolis, and if they consumed more of this diet in comparison to uninfected bees. We do not think that honey bees normally ingest propolis because its toxicity to them has been demonstrated [51,52], but we hypothesized that they can ingest it in moderate amounts when they are challenged by a pathogen as a form of self-medication. The lack of significant differences observed between infected and uninfected honey bees in our choice, scan and food consumption tests did not support the hypothesis that bees therapeutically use propolis in self-medication.…”

“…Two separate experiments were conducted under artificial light at 27 ± 1 • C to compare the candy with crude propolis at two different concentrations (2% in one experiment and 5% in the other) versus the candy without propolis. The two concentrations chosen were below those known to cause lethal and sublethal effects on adult bees [51,52]. In each test, candy devoid of propolis was given in one arm and candy with propolis (at 2% or 5%) was offered in the other arm.…”

Bioactivity of gallic acid–conjugated silica nanoparticles against Paenibacillus larvae and their host, Apis mellifera honeybee

“…During the search of substances for the control of honeybee pathogens, the toxicity against the host organism must be evaluated (Eguaras and Ruffinengo 2006). In several studies, the oral toxicity of natural substances such as propolis, organic acids, essential oils, and their main components has been tested against bees (Ebert 2007;Maistrello et al 2008;Maggi et al 2010;Damiani et al 2017;Porrini et al 2017). Here, the oral toxicity of GA, NP1, NP2, and NPs against workers and toxicity of NP2 against larvae of A. mellifera were proved for the first time.…”

Effect of gibberellic acid on the queen cell production and queen performance in colonies of Apis mellifera L. (Hymenoptera: Apidae)

“…This could be supported by another parameter also measured in the starter colonies for queen rearing: the head weight of the worker bees that attended to the young larvae. Heads of the nurse bees from the colony that received 25 uM GA were heavier, indirectly indicating a larger size of the hypopharyngeal glands (Damiani et al, 2017) of these bees compared to the bees coming from control colony to which 200 uM IAA were supplied. One hypothesis holds that the greater size of the hypopharyngeal glands is related to the quality/quantity of royal jelly, which enhances the acceptance rate of the queen-destined larvae.…”

“…Development of the hypopharyngeal glands is associated with the diameter of the acini (cluster of gland cells), and reflects the number of proteins produced (Deseyn & Billen, 2005). A simple method positively correlates the hypopharyngeal gland acini size to the head fresh weight of worker bees (Damiani et al, 2017). To estimate the development of the hypopharyngeal glands, on day five of treatment (13 days from the start of the trial) (Table I), nurse bees that were feeding/attending to open queen cells were sampled at each starter colony.…”