Lydia McCormick just sent me an abstract of her research for posting here.
Honeybees are the planet’s number one pollinator and, therefore, essential for our agricultural economy because plants depend on them for reproduction. Unfortunately, many health disorders can plague and devastate bee colonies. In the past five years, the small hive beetle (SHB) (Aethina tumida) has become a widespread problem, particularly in the Southeast. In Alabama, this menacing insect is now one of the most common invaders of bee colonies. While beekeepers have used a variety of non-toxic traps or chemical treatments to control SHB, it is also likely that honeybees have natural stress defenses. One possible chemical defense is hydrogen peroxide, produced by glucose oxidase, an enzyme secreted by bees into their honey. Previous observations (“The Effect of Honeybee Pathogens on H202 Content and Glucose Oxidase Activity in Honey”. Science Fair 2008) revealed that honey hydrogen peroxide concentrations were highest in beehives that had small hive beetle (SHB).
The hypothesis that higher hydrogen peroxide concentrations in honey may decrease SHB survival was tested. Groups of 3-5 SHB were incubated at room temperature in containers with cut comb, pollen, and experimental honey for up to 3 months. Nine different experimental H202 concentrations (ranging from 0 mg/ ml to 6000mg/ ml) were added to two different types of honey, natural (raw) versus store-bought. Furthermore, two specific controls were included: 1) a positive control in which the honey was heated to denature protein (enzymes) prior to adding 1600 mg/ ml H202, and 2) a negative control in which honey was pre-incubated with excess catalase to remove native H2O2. Results showed decreased SHB survival after 14 days at concentrations above 1600 mg/ ml H202. By 22-28 days, reduced survival was apparent at 400-800 mg/ ml. At 98 days, all groups showed beetle death, with concentrations above 100 mg/ ml being severely affected. Furthermore, qualitatively, at the lowest concentrations (between 0mg/ ml and 100 mg/ml) beetles showed the most feeding activity as evidenced by feces and chewed combs bits. There was no difference in survival regarding the two honey types. In conclusion, these results suggest that honey H202 may be a natural long-term defense against SHB.
Lydia McCormick - Jefferson County International Bacc.