Effect of honey bee queen mating condition on worker ovary activation

Abstract

The presence of the honey bee queen reduces worker ovary activation. When the queen is healthy and fecund, this is interpreted as an adaptive response as workers can gain fitness from helping the queen raise additional offspring, their sisters. However, when the queen is absent, workers activate their ovaries and lay unfertilized eggs that become males. Queen pheromones are recognised as a factor affecting worker ovary activation. Recent work has shown that queen mandibular pheromone composition changes with queen mating condition and workers show different behavioural responses to pheromone extracts from these queens. Here, we tested whether workers reared in colonies with queens of different mating condition varied in level of ovary activation. We also examined the changes in the chemical composition of the queen mandibular glands to determine if the pheromone blend varied among the queens. We found that the workers activated their ovaries when queens were unmated and had lower ovary activation when raised with mated queens, suggesting that workers detect and respond adaptively to queens of differing mating status. Moreover, variation in queen mandibular gland's chemical composition correlated with the levels of worker ovary activation. Although correlative, this evidence suggests that queen pheromone may act as a signal of queen mating condition for workers, in response to which they alter their level of ovary activation.

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

“…This is similar to findings showing higher levels of ovarian activation in SDIheaded colonies (Mattila et al 2012). The relationship of SDI status to ovarian activation, however, appears to be variable, as other studies have shown that workers are less likely to develop their ovaries in colonies headed by SDI queens (Peso et al 2013;Hoover et al 2003). …”

“…Honey bee queens produce multiple pheromones as well as other compounds not currently considered pheromones (Slessor et al 1988;Hoover et al 2003;Peso et al 2013). SDI queens and naturally mated queens have the potential to differ along many dimensions beyond the contents of their spermathecas, including differences in the early handling of SDI queens related to insemination (Cobey 2007).…”

A conserved class of queen pheromones? Re-evaluating the evidence in bumblebees ( Bombus impatiens )

“…Despite these different predictions, it remains challenging to distinguish between possible queen pheromones and queen signals, because the chemical communication systems of social insects have been found to be intricate and complex. Honeybee queens, for example, produced a complex blend of chemicals from multiple glands that can modulate worker behaviour and physiology, where some of the chemicals are present at significantly higher levels in queens than workers (and some of these can also be produced by reproductive workers), other chemicals change quantity once the queen is mated (even if she is inseminated with only saline), others chemicals change quantity with mating quality and number, and finally, one chemical (homovanillyl alcohol) appears to be a dopamine mimic and thus represent a true 'coercive' pheromone [13][14][15][16][17][18][19][20].…”

When does cheating pay? Worker reproductive parasitism in honeybees

“…While queens do not increase production of QMP as their reproductive output increases Nonacs, 1993, Strauss et al, 2008), the amount of QMP produced by queens has been shown to increase with insemination volume, allowing QMP to act as an honest signal of the queen's reproductive status (Nino et al, 2013a, Nino et al, 2013b. Workers are known to respond to this signal; they are more likely to have active ovaries in the presence of an unmated queen than when they are reared with a mated queen (Peso et al, 2013). Workers further gauge the fertility of their queen via pheromones emitted by the brood (Mohammedi et al, 1996, Mohammedi et al, 1998, Oldroyd et al, 2001b, Strauss et al, 2008, Pettis et al, 1997.…”