Assessing the role of β-ocimene in regulating foraging behavior of the honey bee, Apis mellifera

Abstract

-The larval pheromone (E )-β-ocimene (EBO) inhibits worker ovary development and accelerates the behavioral transition from nursing to foraging in the honey bee, Apis mellifera . Because EBO diffuses throughout the hive, it has been hypothesized that honey bee workers can use it to indirectly assess brood abundance. Here, we evaluate this hypothesis by testing whether EBO plays a role in the regulation of worker foraging activity. We exposed paired colonies to a pulse of either synthetic β-ocimene or paraffin oil control and recorded the subsequent number of pollen and non-pollen foragers returning to the colony. Exposure to synthetic β-ocimene moderately but significantly increased overall foraging activity, but not pollen foraging. For pollen foraging, the effect of pheromone treatment was the greatest directly after pheromone exposure.Apis mellifera / β-ocimene / honey bee foraging / synthetic pheromone / volatility

Behavioural, physiological and molecular changes in alloparental caregivers may be responsible for selection response for female reproductive investment in honey bees

“…Furthermore, the pheromones are separated by larval age: BEP is emitted principally by old larvae and reaches a maximum concentration during the capping stage (Trouiller, Arnold, Le Conte, & Masson, 1991). In contrast, β-ocimene has been identified from different instars with multiple functions (He et al, 2016;Ma, Mueller, & Rangel, 2016;Maisonnasse et al, 2009;Traynor, Le Conte, & Page, 2014;Traynor et al, 2015). Although we cannot exclude its existence in different developmental ages, allo-ocimene has only been found so far in 1-day old larvae, a critical age for queen development that requires a specific signal for the nurse bees to identify queen-destined larvae.…”

A death pheromone, oleic acid, triggers hygienic behavior in honey bees (Apis mellifera L.)

“…Hygienic behavior has been studied in honey bees since at least the 1960s 15 , but our knowledge of the molecular mechanism behind it is incomplete. In the present work, we investigate two candidate hygienic behavior inducers that are emitted from freeze-killed brood – β-ocimene (a co-opted pheromone emitted by brood and queens 42 – 44 , 46 , 47 ) and oleic acid (a well-known necromone and necrophobic compound in other arthropods 1 , 6 , 9 , 10 , 29 – 34 ) – using in vivo , ex vivo , and in vitro techniques. We demonstrated (1) that treating brood with the odorants is sufficient to induce hygienic behavior in realistic behavioral assays (Figs 2B and 3B ), (2) despite being a viscous compound, oleic acid can stimulate nerve depolarizations worker antennae at hive temperatures (Fig.…”

“…β-ocimene, on the other hand, is a volatile honey bee brood pheromone that is normally a larval food-begging signal 42 . β-ocimene emitted from larvae is also known to inhibit worker ovary development 43 , 44 , regulate the nurse-to-forager transition 44 , and stimulate foragers to forage 45 , 46 . The queen also produces β-ocimene, which also contributes to inhibiting worker egg-laying 47 .…”

Honey bees consider larval nutritional status rather than genetic relatedness when selecting larvae for emergency queen rearing

“…The semiochemical E-β-Ocimene was first described in honey bee queens 77 , 78 . However, more recent research has demonstrated it to be also emitted by the larvae, for reasons such as to inhibit ovary development in worker bees 79 , accelerate hypopharyngeal gland development in nurse bees 80 and regulate foraging behavior 81 , 82 . Perhaps more germane to the study presented here, it has recently been shown that larvae produce more E-β-Ocimene after being deprived of food, lending additional support to the idea that larvae communicate nutritional status chemically 36 .…”