Sustainability of varroa resistance in bees used for migratory crop pollination will be determined by measuring survivability and performance of VSH colonies in cooperation with commercial beekeepers. Simplified methods for queen breeders to select for VSH will be evaluated by correlating VSH expression with changes in brood nest characters during short-term exposure of infested combs. Molecular-marker-assisted selection will focus on genetic markers developed earlier for autogrooming and VSH. Traditional breeding will be used to create honey bees suitable for commercial crop pollination by combining lines having high VSH with commercial stock. New traits of resistance to varroa (reduced invasion by mites into brood cells brood-mediated suppression of mite reproduction) or to CCD-related agents will be sought by measuring variation among diverse bee sources. Genes will be further screened for up- and down-regulation using rtPCR assays. Project Methods Traits that are known to confer resistance to mites (autogrooming against tracheal mites VSH or its behavioral subtasks against varroa) will be subjected to microarray analysis to identify genes associated with specific phenotypes.
Identify and assess the role of genes that could potentially be involved in the antifungal activity. Identify molecular bases for honey bee physiological responses to chalkbrood. Objective 4: For varroa sensitive hygiene (VSH) bee stock, use molecular approaches to investigate the physiological basis for bee immune responses to fungal pathogens (such as chalkbrood), and develop strategies for controlling natural honey bee diseases. Objective 3: Develop resistance-based integrated pest management (IPM) systems for management of pests in commercially desired honey bees (other than Russian bees), particularly systems useful for early spring build up. Objective 2: Use traditional breeding and marker-assisted selection (MAS) to develop commercially desired honey bees (other than Russian bees, which are addressed in a sister project) with resistance to parasites (e.g., mites), depredators (e.g., small hive beetle), and diseases (e.g., fungi causing chalkbrood disease), possibly including agents discovered to cause CCD. Goals / Objectives Objective 1: Identify and evaluate traits, genes, and markers associated with honey bee resistance to mites and pathogens, possibly including agents discovered to cause colony collapse disorder (CCD).