Blue Diamond Almond Facts March-April 2021

IN YOUR ORCHARD THE BEE BOX Verifying Survey-Based Beekeeping Best Management Practices with Field Experiments In the last “Bee Box” update from Bee Informed Partnership, we highlighted the recently published research conducted by BIP’s Research Coordinator, Dr. Nathalie Steinhauer and colleagues, that examined four years of U.S. honey bee colony health, survival and management information collected through BIP’s Annual Colony Loss and Management Survey (Steinhauer, Staeger & vanEngelsdorp 2021 Science of the Total Environment vol. 753). The goal of this work was to evaluate the association between beekeeper management practices and colony survival rates and to determine whether differences in management practices that are shown to be associated with lower colony mortality according to survey data analyses are confirmed with field experiments. What management mattered most? Four beekeeping management actions had the greatest impact on colony survival rate in small-scale beekeeping operations (0–50 colonies): 1 ) Regularly replacing old comb; 2) action on deadouts – either rapidly reusing equipment from colonies that have died, or freezing equipment prior to reuse rather than storing and reusing without freezing (unless colonies died as a result of transmissible infectious diseases, such as American Foulbrood, in which case equipment must not be reused or sterilized with specific protocols); 3) implementing a Varroa management plan where Varroa are treated when they reach the critical threshold level of three Varroa /100 bees; and 4) creating new colonies by dividing existing colonies, rather than purchasing packages as a source of new colonies ( Table 1 ). Table 1. Average practices vs. BMPs to be tested in the field. Management Practice Average Practice Best Management Practice Action on Deadout Store equipment for later use Reuse equipment immediately by adding to living colonies or using for a split Varroa control frequency Apply miticides once in fall Monitor monthly and apply miticides when above 3.0 mites/100 bees Starting new colonies Packages Make splits when possible and buy nucs if splits impossible Comb-culling technique Do not treat old brood comb before reuse Freeze old brood comb before reuse Following up with field experiments – To determine whether beekeeping management practice recommendations drawn from survey data reported to improve honey bee colony survival rates could be experimentally-reproduced, Dr. Kelly Kulhanek at the University of Maryland and colleagues conducted a multi-year field study to compare 2 4 A L M O N D F A C T S