Short-term effect of different weather conditions upon the behaviour of forager and nurse honey bees (Apis mellifera carnica Pollmann)

Abstract

Summary — Nurses and foragers were observed around noon and around midnight during good and bad weather conditions. Foragers were very busy on sunny days with almost no periods of inactivity. More than 60% of the observation period around noon they spent outside the hive. When foragers were prevented from flight by the lack of light or by bad weather, they showed long periods that were defined as unproductive and trophallactic contacts were reduced. Nurses aged 7-9 days showed a less pronounced behavioural difference between day and night but were highly sensitive to weather alterations. They spent less than half of the time nursing the brood during bad weather conditions compared to good weather conditions, although there was no lack of pollen and honey in the colony. The same tendency was observed in other nurse-related activities. They were less often fed by other bees during days with bad weather conditions than during days with good weather conditions. These dramatic changes in behaviour could be observed even on the first day of rain. We presume that the decline of activity is at least partly caused by the diminishing flow of food within a colony.social behaviour / division of labour / weather / day and night INTRODUCTION

Pesticide risk assessment in free-ranging bees is weather and landscape dependent

“…15, that is, if non-returning treated bees represent more than 15% of returning bees, one might expect from the control. For the sake of illustration, we therefore targeted a critical m HF value of 20% and mapped the corresponding required thiamethoxam dose, called ED 20 (Fig. 4).…”

“…Herein, Navigation Evironmental Correlate, thereafter abbreviated as NECs, refer to those extrinsic drivers of bee navigation and flight performances, comprising weather conditions (temperature, cloudiness or visibility of sun) and salient landmarks acting as visual cues for orientation [13][14][15][16][17][18][19][20][21][22] . Homing honeybees rely on a network of learned interconnected vectors for orientation 18 , conceptualized as memorized distances and directions among known locations.…”

Intergenerational transfers may have decoupled physiological and chronological age in a eusocial insect

“…The activities within a bee colony are easy to quantify, and patterns of nursing and food exchange have been studied thoroughly (e.g., Riessberger and Crailsheim, 1997;Crailsheim et al, 1999). Honey bees have three types of colony members: queens, males (drones) and workers.…”

“…Trophallactic interactions are non-random, and they depend on factors such as sex and age of the receiver and donor, food availability and quality, time of day, weather and season (Riessberger and Crailsheim, 1997;Crailsheim, 1998;Crailsheim et al, 1999). Two main commodities are transferred by trophallaxis: (i) floral nectar, which provides the bees with carbohydrates.…”

“…Nurse bees, but not foragers, consume more pollen during days of bad weather (Riessberger and Crailsheim, 1997). These resources are not transferred, but appear to be stored in the nurse bees' bodies as storage protein (Amdam and Omholt, 2002).…”