More Worker Capped Brood and Honey Bees with Less Varroa Load Are Simple Precursors of Colony Productivity at Beekeepers' Disposal: An Extensive Longitudinal Survey.

In response to the concerns of beekeepers on the decline of honey bee populations on lavender honey flow in the lavender fields of southeast France and the consequent decrease of honey production, our long-term survey (2009-2021) monitored the total weight gain collected by these colonies. This study shows the variations in the total weight gain according to regions, years, populations structure (bee number and quantity of capped brood) and Varroa load. Among these factors, years and regions support one third of the variations over this 13-year survey.

To Treat or Not to Treat Bees? Handy VarLoad: A Predictive Model for Load.

The parasitic is considered a major pathogenic threat to honey bees and to beekeeping. Without regular treatment against this mite, honey bee colonies can collapse within a 2-3-year period in temperate climates. Beyond this dramatic scenario, Varroa induces reductions in colony performance, which can have significant economic impacts for beekeepers.

ColEval: Honeybee COLony Structure EVALuation for Field Surveys.

Methods for the evaluation and comparison of the structure of numerous honeybee colonies are needed for the development of applied and fundamental field research, as well as to evaluate how the structure and activity of honeybee colonies evolve over time. ColEval complements existing methods, as it uses an online reference image bank for (human) learning and training purposes. ColEval is based on the evaluation of the surface area percentage occupied by different components of a honeybee colony: adult worker bees, open and capped brood, honey, nectar, and pollen.

Measuring biological age to assess colony demographics in honeybees.

Honeybee colonies are increasingly exposed to environmental stress factors, which can lead to their decline or failure. However, there are major gaps in stressor risk assessment due to the difficulty of assessing the honeybee colony state and detecting abnormal events. Since stress factors usually induce a demographic disturbance in the colony (e.

Combined neonicotinoid pesticide and parasite stress alter honeybee queens' physiology and survival.

Honeybee colony survival strongly relies on the queen to overcome worker losses exposed to combined stressors like pesticides and parasites. Queen's capacity to withstand these stressors is however very little known. The effects of the common neonicotinoid pesticide imidacloprid in a chronic and sublethal exposure together with the wide distributed parasite Nosema ceranae have therefore been investigated on queen's physiology and survivorship in laboratory and field conditions.

Neuronal plasticity in the mushroom body calyx during adult maturation in the honeybee and possible pheromonal influences.

Honeybee workers express a pronounced age-dependent polyethism switching from various indoor duties to foraging outside the hive. This transition is accompanied by tremendous changes in the sensory environment that sensory systems and higher brain centers have to cope with. Foraging and age have earlier been shown to be associated with volume changes in the mushroom bodies (MBs).

Flight behavior and pheromone changes associated to Nosema ceranae infection of honey bee workers (Apis mellifera) in field conditions.

Parasites are known to cause the loss of individuals in social insects. In honey bee colonies the disappearance of foragers is a common factor of the wide extended colony losses. The emergent parasite of the European honey bee Nosema ceranae has been found to reduce homing and orientation skills and alter metabolism of forager bees.

Seasonal variation in the titers and biosynthesis of the primer pheromone ethyl oleate in honey bees.

Honey bees allocate tasks along reproductive and non-reproductive lines: the queen mates and lays eggs, whereas the workers nurse the brood and forage for food. Among workers, tasks are distributed according to age: young workers nurse and old workers fly out and forage. This task distribution in the colony is further regulated by an increase in juvenile hormone III as workers age and by pheromones.

Sensory reception of the primer pheromone ethyl oleate.

Social work force distribution in honeybee colonies critically depends on subtle adjustments of an age-related polyethism. Pheromones play a crucial role in adjusting physiological and behavioral maturation of nurse bees to foragers. In addition to primer effects of brood pheromone and queen mandibular pheromone--both were shown to influence onset of foraging--direct worker-worker interactions influence adult behavioral maturation.

Biosynthesis of ethyl oleate, a primer pheromone, in the honey bee (Apis mellifera L.).

Honey bees undergo a physiological transition from nursing to foraging approximately 21 days after adult emergence. This transition is delayed by ethyl oleate (EO), a primer pheromone produced by foragers when exposed to ethanol from fermented nectar. We demonstrate here that two secreted α/β-hydrolases (BeeBase ID: GB11403 and GB13365) are responsible for the reversible esterification of ethanol with oleic acid, giving EO.

E-β-ocimene, a volatile brood pheromone involved in social regulation in the honey bee colony (Apis mellifera).

Background: In honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae) was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-β-ocimene, which partially inhibits ovary development in workers.

New insights into honey bee (Apis mellifera) pheromone communication. Is the queen mandibular pheromone alone in colony regulation?

Background: In social insects, the queen is essential to the functioning and homeostasis of the colony. This influence has been demonstrated to be mediated through pheromone communication. However, the only social insect for which any queen pheromone has been identified is the honey bee (Apis mellifera) with its well-known queen mandibular pheromone (QMP).

Nosema spp. infection alters pheromone production in honey bees (Apis mellifera).

Pheromones in social insects play a key role in the regulation of group homoeostasis. It is well-established that parasites can modify hormone signaling of their host, but less is known about the effect of parasites on pheromone signaling in insect societies. We, thus, tested in honey bees (Apis mellifera) the effect of the widespread parasite Nosema spp.