|Resistance to Varroa in Russia|
USDA-ARS Project to Evaluate Resistance to Varroa jacobsoni by Honey Bees of Far-Eastern Russia
Apis mellifera is not native to the Primorsky Territory on Russia's Pacific coast, but was first moved there in the last century. At that time, pioneers from western Russia took advantage of the completion of the Trans-Siberian Railway and moved bees from European western Russia to the Primorsky Territory in Asian far-eastern Russia. This far-eastern area of Russia is within the natural range of Apis cerana, the original host of Varroa jacobsoni. Thus A. mellifera was brought into the likely range of V. jacobsoni even before the parasite was scientifically described in 1904. This probable long association of V. jacobsoni and A. mellifera in the region has engendered one of the best opportunities in the world for A. mellifera to develop genetic resistance to V. jacobsoni.
The USDA-ARS Honey Bee Breeding, Genetics & Physiology lab, Baton Rouge, LA, explored whether such resistance might be found in Primorye populations of honey bees in the autumn of 1994. Data were collected showing that colonies in the area did have Varroa infestation, but that the levels were lower compared to U.S. colonies.
Dr. Victor Kuznetsov (second from left), Dr. Tom Rinderer (middle) and Gary Delatte (right) inspect bees under a microscope for the presence of Varroa.
The experimental yard in Khorol, Primorsky, approximately 200 km NW of Valdivostock
In June 1995, a test apiary was established in Primorsky. Queens from a variety of sources in the territory were introduced into 50 colonies. Mite levels were equalized among colonies, and thereafter no treatments for mite control were undertaken. Between August 1995 and September 1996, monthly infestation rate data for worker and drone brood were collected. For comparison, we ran a test in Baton Rouge, collecting similar data.
Russian cooperators, among them Dr. Victor Kusnetsov (right) and Anatoly Reshetnikov (second from left), the beekeeper who managed the experimental colonies used in the project.
Worker brood infestation remained quite low in the Primorsky bees. Even 15 months after the last treatment, the average infestation was only 7%. In the U.S. , 12 months after treatment, the average infestation was 33% and many of the colonies were collapsing with "parasitic mite syndrome". In the summer of 1996, the average infestation in the U.S. colonies rose substantially, but did not rise in the Russian colonies.
A similar difference occurred on drone brood infestations. In colonies in both areas Varroa infestations were higher in drones. In Russian colonies, the highest average infestation of 39% occurred in June 1996 and average infestations declined after thereafter. In U.S. colonies, infestation rates began at 37% and continued to rise to an average of 76% in August 1996. At this time the colonies were treated with Apistan in order to keep them from dying.