Egg‐size plasticity in Apis mellifera: Honey bee queens alter egg size in response to both genetic and environmental factors

Abstract

Social evolution has led to distinct life‐history patterns in social insects, but many colony‐level and individual traits, such as egg size, are not sufficiently understood. Thus, a series of experiments was performed to study the effects of genotypes, colony size and colony nutrition on variation in egg size produced by honey bee (Apis mellifera) queens. Queens from different genetic stocks produced significantly different egg sizes under similar environmental conditions, indicating standing genetic variation for egg size that allows for adaptive evolutionary change. Further investigations revealed that eggs produced by queens in large colonies were consistently smaller than eggs produced in small colonies, and queens dynamically adjusted egg size in relation to colony size. Similarly, queens increased egg size in response to food deprivation. These results could not be solely explained by different numbers of eggs produced in the different circumstances but instead seem to reflect an active adjustment of resource allocation by the queen in response to colony conditions. As a result, larger eggs experienced higher subsequent survival than smaller eggs, suggesting that honey bee queens might increase egg size under unfavourable conditions to enhance brood survival and to minimize costly brood care of eggs that fail to successfully develop, and thus conserve energy at the colony level. The extensive plasticity and genetic variation of egg size in honey bees has important implications for understanding life‐history evolution in a social context and implies this neglected life‐history stage in honey bees may have trans‐generational effects.

Honeybee (Apis mellifera) Maternal Effect Causes Alternation of DNA Methylation Regulating Queen Development

“…He et al (2017) and Wei et al (2019) found that queens developed from queen cells are better than queens reared from worker cell eggs and young larvae. A recent study clearly showed that honeybee queens have an ability to alter egg size in response to both genetic and environmental factors (Amiri et al, 2020). Therefore, honeybee maternal effects may potentially influence the quality of the queen.…”

Honey Bee Queens and Virus Infections

“…Although the queen is thought to be protected by several social immune mechanisms in the colony, she is exposed to different environmental stresses during different life stages that possibly have negative effects on her health and quality [24]. Initially, a queen can be influenced by the environment that her parents experienced as a result of a trans-generational stress response [25][26][27][28]. She can also be influenced by different environmental stressors during development, either through exposure to biotic or abiotic stressors in the colony environment or specifically via the quality or quantity of royal jelly she receives [29][30][31][32][33].…”

Fertility costs of cryptic viral infections in a model social insect

“…This reduction of vitellogenin relative to the other proteins in smaller ovaries therefore suggests that the decrease in ovary size is associated with a disruption in egg production. This could alternatively indicate a reduction in the volume of vitellogenin being provisioned to each egg without the development of eggs being interrupted, as honey bee egg size has been shown to be plastic in response to external signals previously 72 . Vitellogenin is also responsible for the binding and transport of immune elicitors ( i .…”