Submitted to: Journal of Economic Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/31/2008
Publication Date: 2/1/2009
Citation: Frake, A.M., De Guzman, L.I., Rinderer, T.E. 2009. Comparative resistance of Russian and Italian honey bees (Hymenoptera: Apidae) against small hive beetles (Coleoptera: Nitidulidae). Journal of Economic Entomology 120(1):13-19 Interpretive Summary: Small hive beetles (SHB) continue to expand their distribution and remain a beekeeping problem of economic importance. This study evaluates the use of Russian honey bees, which are known for their resistance to parasitic mites, in regulating SHB populations in the colonies. Comparing them with Italian honey bees, we counted the numbers of invading beetles, populations through time, and their ability to reproduce inside the colonies. Our results showed that Russian honey bees were more resistant to SHB than Italian honey bees as indicated by fewer invading beetles, lower SHB population through time and lesser reproduction. The number of beetles was not influenced by adult bee population, amount of brood produced, or the amount of pollen available inside the colonies. Regardless of honey bee stock, colonies with entrance reducers installed had fewer SHB than those without entrance reducers. However, entrance reducers did not affect brood and bee production.
Technical Abstract: To compare resistance to small hive beetles (SHB) between Russian and commercial Italian honey bees, the numbers of invading beetles, their population levels through time and SHB reproduction inside the colonies were monitored. We found that the genotype of queens introduced into nucleus colonies had no immediate effect on SHB invasion. However, the influence of honey bee stock on SHB invasion was pronounced once test bees populated the hives. In colonies deliberately freed from SHB during each observation period, the average number of invading beetles was higher in the Italian colonies (29 ± 5 beetles) than in the Russian honey bee colonies (16 ± 3 beetles). A similar trend was observed in colonies that were allowed to be freely colonized by beetles throughout the experimental period (Italian = 11.46 ± 1.35; Russian = 5.21 ± 0.66 beetles). A linear regression analysis showed no relationships between the number of beetles in the colonies and adult bee population (r2 = 0.1034, P = 0.297), brood produced (r2 = 0.1488, P = 0.132), or amount of pollen (r2 = 0.1036, P = 0.295). There were more Italian colonies that supported SHB reproduction than Russian colonies. Regardless of stock, the use of entrance reducers had a significant effect on the average number of SHB (with reducer = 16 ± 3, without reducer = 27 ± 5 beetles). However, there was no effect on bee population (with reducer = 13.20 ± 0.71, without reducer = 14.60 ± 0.70 frames) or brood production (with reducer = 6.12 ± 0.30, without reducer = 6.44 ± 0.34 frames). Overall, Russian honey bees were more resistant to SHB than Italian honey bees as indicated by fewer invading beetles, lower SHB population through time and lesser reproduction.