Advanced selection program for Authentic Apis mellifera carnica

Varroa Sensitive Hygiene (VSH) is a behavioral trait of honey bees (Apis mellifera) in which bees detect and remove bee pupae that are infested by the parasitic mite Varroa destructor. This behavior involves nest-cleaning bees recognizing infested brood aged 15–18 days old and removing the mite-infested bee pupae from their brood cells, which kills any immature varroa mites present. VSH activity results in an abnormally low proportion of mites that produce offspring within the colony. Bees with the VSH trait were initially bred by the United States Department of Agriculture (USDA) Honey Bee Genetics and Physiology Laboratory in Baton Rouge, Louisiana, and the trait has been shown to be an important mechanism of resistance to varroa mites. The VSH trait can be measured using tests such as the pin-killed brood test, where researchers wound or kill a number of pupae inside capped cells and observe the rate at which the colonies remove the damaged or killed brood. The VSH trait is crucial for controlling varroa mite infestations, and colonies with this trait can be selected and bred for improved resistance to varroa mites

Hygienic behaviour is recognized as a natural antiseptic defence against the brood diseases, American foulbrood and chalkbrood, and against varroa (Boecking and Spivak, 1999; Evans and Spivak, 2010; Spivak and Reuter, 2001; Wilson-Rich et al., 2009) and thus may be relevant in breeding programmes for resistance to these pathogens and parasite. Standardized methods for testing hygienic behaviour are based on the removal of freeze killed (Momot and Rothenbuhler, 1971; Spivak and Reuter, 1998) or pin killed brood (Newton and Ostasiewski, 1986). Furthermore, Harbo and Harris (2005) described a method to check for a specific hygiene behaviour induced by reproducing mites in brood cells, called Varroa Sensitive Hygiene (VSH).