Honey loading for pollen collection: regulation of crop content in honeybee pollen foragers on leaving hive

Abstract

Before foraging honeybees leave the hive, each bee loads its crop with some amount of honey "fuel" depending on the distance to the food source and foraging experience. For pollen collection, there is evidence that foragers carry additional honey as "glue" to build pollen loads. This study examines whether pollen foragers of the European honeybee Apis mellifera regulate the size of the crop load according to food-source distances upon leaving the hive and how foraging experience affects load regulation. The crop contents of bees foraging on crape myrtle Lagerstroemia indica, which has no nectary, were larger than those foraging on nectar from other sources, confirming a previous finding that pollen foragers carry glue in addition to fuel honey from the hive. Crop contents of both waggle dancers and dance followers showed a significant positive correlation with waggle-run durations. These results suggest that bees carry a distance-dependent amount of fuel honey in addition to a fixed amount of glue honey. Crop contents on leaving the hive were statistically larger in dancers than followers. Based on these results, we suggest that pollen foragers use information obtained through foraging experience to adjust crop contents on leaving the hive.

Adjustment of honey load by honeybee pollen foragers departing from the hive: the effect of pollen load size

“…Some of the honey at departure is used as fuel for flight (Beutler 1950;Gmeinbauer and Crailsheim 1993). This behavior is well described in the honeybee Apis mellifera (Parker 1926;Beutler 1950;Hodges 1952;Harano et al 2013Harano et al , 2014 and is suggested in stingless bees (Leonhardt et al 2007).…”

“…We used the same methods and procedures as in previous studies (Harano et al 2013(Harano et al , 2014 unless otherwise stated. Briefly, waggle dancers and their followers were classified by the size of pollen load presented by dancers and the amount of honey at departure was compared among groups with a different size of pollen load.…”

“…Briefly, waggle dancers and their followers were classified by the size of pollen load presented by dancers and the amount of honey at departure was compared among groups with a different size of pollen load. Waggle-run duration was also recorded because honey at departure is affected by the distance to the food source to which they will fly (Beutler 1950;Harano et al 2013Harano et al , 2014.…”

“…In some social bees, the glue for the pollen load is carried from the nest (Parker 1926;Beutler 1950Beutler , 1951Leonhardt et al 2007). For example, honeybee pollen foragers leave the hive with a crop partially filled with honey (this honey is referred to as ''honey at departure'' hereafter) and mix the honey with collected pollen during foraging (referred to as ''glue honey'') (Beutler 1950;Harano et al 2013Harano et al , 2014. Some of the honey at departure is used as fuel for flight (Beutler 1950;Gmeinbauer and Crailsheim 1993).…”

“…Honeybees communicate location of food sources using the waggle dance (von Frisch 1967). Potential recruits leave the hive with an amount of fuel corresponding to the food source distance indicated by waggle dances (Harano et al 2013(Harano et al , 2014. Previous study showed that followers have more honey at departure when they followed dances of pollen foragers than when following nectar foragers, suggesting that dancers convey information about the type of food material available at the indicated site and followers can use this information (Harano et al 2013).…”