Comparative Resistance of Four Honey Bee (Hymenoptera: Apidae) Stocks to Infestation by Acarapis woodi (Acari: Tarsonemidae)

Abstract

The prevalence, mean intensity, and abundance of Acarapis woodi (Rennie) in 4 selected stocks of honey bees (Apis mellifera L.) were monitored under field conditions. The test stocks used were ARS-Y-C-1 (A. mellifera carnica imported from Yugoslavia), Hastings (A. mellifera carnica imported from northern Saskatchewan), F1 hybrid between ARS-Y-C-1 and Hastings, and Louisiana stock available at the Baton Rouge laboratory apiaries. Two trials were conducted. The 1st trial used 20 colonies per stock and continued for 2 yr. The 2nd trial used 10 colonies per stock and was monitored for 1 yr. Results of both trials showed that ARS-Y-C-1 and F1 hybrids consistently maintained approximately a 10% level of A. woodi infestation, which is below the level that causes economic damage to host colonies. These stocks also had significantly lower mean intensities of mites than the Hastings and Louisiana bees. A. woodi was least abundant in the F1 hybrid. Similar numbers of mites per bee were found in ARS-Y-C-1, Hastings and Louisiana stocks. These observations suggest that both ARS-Y-C-1 and F1 hybrids are resistant to A. woodi.