The impacts of maternal stress on worker phenotypes in the honey bee

Abstract

Maternal stress is a common source of heritable health and behavioral variation. This type of maternal effect could be particularly important for honey bees (Apis mellifera), as a single queen is responsible for many generations of workers who perform all colony functions including raising subsequent worker generations. Multiple factors work synergistically to cause colony loss, but a role for maternal stress effects is unstudied. We used an artificial cold temperature treatment as a proof-of-concept approach to investigate whether acute queen stress causes changes in worker phenotypes, including egg hatching rate, development time, and adult behavior and immune function. We found that queen stress impacts early-life phenotypes (egg hatching and development time), with more limited impacts on adult phenotypes (behavior and immune function). Thus, if maternal stress impacts colony health, it is likely through cumulative impacts on worker population numbers, not through phenotypic effects that impact individual adult worker behavior or health resilience. This study addresses an important and overlooked question, and provides a baseline understanding of the likely impacts of queen stress on worker phenotypes.