"In the middle of difficulty lies opportunity" Varroa Sensitive Hygiene and Mite Reproduction Selecting for Varroa Sensitive Hygiene Questions and answers about VSH USDA ARS scientists Dr. John Harbo and Dr. Jeffrey Harris Bee Breeding Laboratory in Baton Rouge, Louisiana, have defined and tested a trait of the honeybee which appeared to suppress mite reproductionRecently it has been better defined as "varroa sensitive hygieneThis is a form of behavior where adult bees remove pupae that have reproductive mites but do not disturb pupae that have mites that produce Dr. Harbo and Dr. Harris proved the effectiveness of the VSH trait by exchanging queens between resistant and susceptible colonies. Each time a resistant queen was put into a susceptible colony, the miteOn the other hand, every time a susceptible queen was placed in the resistant colonies, the mite population increased. Recent studies by Dr. Spivak and Dr. Harbo have shown that

the SMR trait might be best described as a "varroa-sensitive hygienicVSH bees remove mites that have started to reproduce. The reproduction of mites triggers their removal by the bees. left in the cells are non reproductive or sterile. So there is evidence for selective removal of reproductive mites from brood cells. A goal of the USDA SMR Project is to distribute the VSH trait for resistance to Varroa mites to queen breeders around the country. The object is to cross these bees with beekeeper's own well adapted stock. This will maintain the genetic diversity of American bees while enhancingOnce in the hives of beekeepers, further selection and improvement can be made for honey production, other disease resistance mechanisms, and other beneficial traits. Recent tests have shown that VSH queens retain an acceptable level of mite resistance when they are free mated to unselected drones. The best way to get the maximum amount of the trait into

a line of bees is to begin with a pure VSH breeder queen so her daughters mate with your local drones. The VSH trait has proven to be extremely effectiveProm Dress Hemmed Too ShortIt holds great promise as a permanent solution, butWeight Loss Blackstrap Molasses the work is not yet finished. Hankook Tires For Honda CrvThere is still considerable variation in crosses with different lines of bees, and so should still be thought of as as aWith the recent retirement of Dr. Harbo from the bee lab, Dr. Bob Danka , Dr. Jeffrey Harris and the team at the USDA Baton Rouge Bee Lab are carrying on the work. Simplified methods of evaluating colonies for levels of Varroa Sensitive Hygiene (VSH) 2009 Journal of Apicultural Research

Comparative Performance of Two Mite-Resistant Stocks of Honey Bees in Alabama Beekeeping Operations 2008 J. of Economic Entomology THE VSH TRAIT EXPLAINED BY HYGIENIC BEHAVIOR OF ADULT BEES Cleaning House-and Hive - A special line of bees uses the power of hygiene to fend off its worst foe. Line of Bees "Sniffs Out" Its Worst Enemy- ARS SMR-This Honey of a Trait Protects Bees From Deadly Mites - ARS The Relationship of Between Suppression of Mite Reproduction (SMR) and Hygienic Behavior, Ibrahim, A. and Spivak, M. American Bee Journal, May 2004 The SMR Trait Explained by Hygienic Behavior of Adult Bees - American Bee Journal 145(5):430-431 The Number of Genes Involved in the SMR Trait - American Bee Journal 145(5):430 An Evaluation of Commercially-Produced Queens That Have the SMR Trait - ABJ 143:213-216 "Varroa Resistance of Hybrid ARS Russian Honey Bees"-AmericanBreeding Honey Bees that Suppress Mite Reproduction Natural and Suppressed Reproduction of Varroa, Bee Culture, May 2001

SMR Queens : an Update - Bee Culture, Further Reference about VSH beesWhere did VSH bees come from? VSH bees were originally selected from diverse domestic honeybee colonies in Louisiana and Michigan that showed some degree of miteThey are all American bees. What's special about these bees? the VSH trait might be best described as a "varroa sensitive hygienicSo there is evidence that bees with the VSH trait selectively remove reproductive mites from brood Are VSH bees related to the USDA Russian bees?Though coming out of the same USDA ARS research laboratory as the Russians, they are not related. VSH bees are not imported, they originated from domestic American colonies. What is the VSH project? A goal of the USDA ARS VSH Project is to distribute this mite resistance trait to queen breeders around the country. is to cross these bees with beekeeper's own well adapted stock, thus maintaining the genetic diversity of American bees while introducing this important

Once in the hives of beekeepers, further selection and improvement can be made for honey production, other disease resistance mechanisms, and Are the genes for suppressed mite reproduction dominant The VSH trait is thought to be controlled by more than one gene, just how many is uncertain at this point. These genes are neitherThey are what is called "additive" which simply means that the more of them that are present, the more strongly the traitThis works in favor of beekeepers since a queen with VSH genes can mate to any drones and still have the trait expressed in her colony enough to reduce the mite population. So naturally mated queens produced from pure VSH breeders are mite resistant. Who should buy pure VSH breeder queens? Pure VSH breeder queens should be used for queen rearingThe best way to get the maximum amount of the trait into a line of bees is to begin with a pure VSH breeder queen so her daughters mate with your local drones.

Daughter queens of pure VSH breeders who are out crossed by natural mating have good brood production and an acceptable level of mite resistance. The naturally mated daughters of these breeder queens should be used for production hives. containing 50% of the VSH trait can be purchased from various queen producers. How do you know VSH bees are mite resistant? In a recent published study Dr. Harris and Dr. Harbo proved the effectiveness of the VSH trait by exchanging queens between resistantEach time a resistant queen was put into a susceptible colony, the mite population went down. On the other hand, every time a susceptible queen was placed in the resistant colonies, the mite population increased.In another study by Dr. Marla Spivak at the University of Minnesota, bees of several strains were compared. showed the highest degree of mite resistance, and also had good honey production. What is the difference between VSH and SMR bees?

This line was originally called SMR for Suppressed Mite Reproduction because that was the apparent cause of the resistance to varroa mites. However after further research, it was learned that the real cause was a type of hygienic behavior that was sensitive to the presence of reproductive varroa mites. With this clarification of the mode of resistance, SMR was renamed VSH for Varroa Sensitive Hygiene to be more accurate.Further reading on VSH bees: If there is one good thing about varroa mites, it is that they are large enough to see fairly easily. With a magnifying glass, a flashlight, and a little time to look, the VSH trait can be observed in any stockThe USDA maintains a web site on Varroa mite reproduction which has an excellent display of pictures and descriptions of mites, both reproductive and non-reproductive. Your time will be well repaid by studying this site before you begin your own observations. 1. Uncap purple eyed pupae with tan body color.