Experimental manipulation of the reproductive quality of honey bee queens (Apis mellifera L.)

Highly eusocial insects exhibit a strong reproductive division of labor. In honey bee colonies, reproduction is monopolized by a single reproductive female, or queen, while her daughter workers are facultatively sterile. Caste determination, however, is a consequence of environmental conditions during development, where female larvae may become either queens or workers depending on their larval diet. This bipotency introduces significant variation in the potential reproductive quality of queen bees, with queens raised from young worker larvae exhibiting a high reproductive potential and queens raised from older worker larvae exhibiting a lower reproductive potential. Here we confirm previous findings that low-quality queens are produced from older larvae, as measured morphometrically (e.g., weight and body size) and by stored sperm counts. We also show, for the first time, that low-quality queens mate with significantly fewer males, which is responsible for the decreased numbers of stored sperm in low-quality queens. These results illustrate the reproductive continuum of honey bee queens and the degree to which colonies may maximize the fitness potential of their reproductive female.