|De Guzman, Lilia|
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/17/2006
Publication Date: 3/1/2007
Citation: De Guzman, L.I., Rinderer, T.E., Frake, A.M. 2007. Growth of varroa destructor (acari: varroidae) populations in russian honey bee (hymenoptera: apidae) colonies. Annuals of the Entomological Society of America 100(2):187-195
Interpretive Summary: Several studies have shown that Russian honey bees are resistant to varroa mites. However, a full examination of the possible mechanisms of resistance to varroa mites that may occur in Russian honey bees has not been reported. This study examined the role of various infestation parameters and honey bee colony populations in regulating mite population growth in Russian honey bee colonies. Results from three experiments confirmed previous studies that Russian honey bees support slow growth of varroa mite population. This poor growth of varroa mites in the Russian honey bee colonies could be attributed to several factors including non-preference or brood unattractiveness as shown by their low proportions of brood infested and multiply-infested cells of both worker and drone brood. In addition, reduced reproduction of mites and extended phoretic period for the mites appeared to influence mite growth. These factors appear to act in concert and cause substantial inhibition of varroa mite population growth.
Technical Abstract: The growth rate (r) of Varroa destructor populations in Russian and Italian honey bee (Apis mellifera L.) colonies was monitored from 2001 to 2003 in Baton Rouge, Louisiana. Over this period, our results consistently showed lower mite growth in the Russian than in the Italian colonies. In 2001, instantaneous growth rates per week (r7) were 0.191 ± 0.011on Italian and r7 = 0.137 ± 0.012 on Russian honey bees in 24.3 weeks equivalent to 159.1- and 61.6-fold increase, respectively. Divergence in r7 values was also observed in 2002 when Russian colonies supported a lower growth rate of r7 = 0.061 ± 0.016 (9.3-fold increase) than the Italian colonies (r7 = 0.122 ± 0.01 or a 31.7-fold increase) did after 26 weeks. The lowest rate of r7 = 0.021 ± 0.011 (a 1.4-fold increase) was recorded for Russian honey bees in 2003 while the Italian bees in that year supported r7 = 0.145 ± 0.009 (an 18.9-fold increase) after 19 weeks. This low growth rate of mite populations in Russian colonies maybe attributed to several factors. Notably, as this study showed, Russian bees are less attractive to varroa mites. Furthermore, the Russian stock supported low proportions of brood infested and fewer multiply-infested cells in both worker and drone brood, reduced mite reproduction and extended phoretic period.