Spotty brood; uncapped worker pupae; workers removing pupae from their cells; mites falling to debris board with legs missing.
Hygienic queen (or hygienic bee stock) means worker bees police the developing brood for any irregularities such as diseases. However, the term hygienic is largely focused on worker bees seeking and removing reproducing mites in capped brood cells by removing infested brood, behavior defined as "varroa sensitive hygiene."
Hygienic behavior is thought to be an inheritable genetic trait and is highly desirable. It means the bees are seeking to control mites. The degree of hygienicity can be assessed by freeze-drying (with liquid nitrogen or dry ice) a patch of capped brood worker cells (about 100 cells) and then checking in 24 hours for number of brood removed. Results from another method, called the "pin prick" or "pin kill" test, are difficult to interpret.
Natural selection is a process whereby beekeepers allow their colonies to perish, using survivor stock to generate new queens for requeeningrequeen:
to replace a queen; old queens are often removed and replaced by a ripe queen cell or by a mated queen via an introduction cage
. Losses will initially be quite extensive, but after three or so years the stock should show improvement, unless there is continued introduction of drones from other beekeepers into the area, in other words large numbers of beginners starting packages or nucs and/or commercial beekeepers locating bees in the area during the mating season.
Hygienic bee stock is also evaluated for their degree of mite-biting behavior. Mites killed by worker bees will have legs removed, resulting in the mites desiccating and falling to debris boards. The presence of dead mites with this injury can be an assessment of the degree to which the bee stock has this hygienic quality.
spotty brood patternspotty brood pattern:
capped worker cells that are not uniformly solid within the brood sphere; numbers of cells lacking brood of the same brood age; indicative of poor colony queen or poor health
Mondet F, et al. 2021. Chemical detection triggers honey bee defense against a destructive parasitic threat. Nature Chemical Biology 17:524-530.
Al Tuofailia H, et al. 2018. Both hygienic and non-hygienic honeybee, Apis mellifera, colonies remove dead and diseased larvae from open brood cells. Philosophical Transactions of the Royal Society 373(1751): 20170201 https://royalsocietypublishing.org/doi/10.1098/rstb.2017.0201
“Hygienic bees kills honey bees”. YouTube, uploaded by Inside The Hive TV, 3 October 2021. https://www.youtube.com/watch?v=Fz0NU8HM1Rg
Erez T, Bonda E, Kahanov P, Rueppell O, Wagoner K, Chejanovsky N, and Soroker V. 2022. Multiple benefits of breeding honey bees for hygienic behavior. Journal of Invertebrate Pathology 193(107788). https://www.sciencedirect.com/science/article/pii/S0022201122000738?via%3Dihub
