Varroa sensitive hygiene
Encyclopedia
Varroa sensitive hygiene (VSH) is a behavioral trait of honey bee
s (Apis mellifera) in which bees detect and remove bee pupa
e that are infested by the parasitic mite
Varroa destructor
. V. destructor is considered to be the most dangerous pest problem for honey bees worldwide. VSH activity results in significant resistance to the mites.
from colonies in which mite populations grew only slowly.
The factor causing slow mite population growth
was found to be heritable
. The rate of mite population growth was found to be correlated with the reproductive rates of mites, resulting in naming the factor “suppressed mite reproduction” (SMR). It was subsequently discovered that the factor is founded on hygienic activity
of adult bees, so SMR was renamed VSH.
VSH activity results in (1) an abnormally low proportion of mites that produce offspring within the population that remains in capped brood and (2) reduction of the brood infestation rate by greater than 70%. The specifics of how hygienic bees detect mite infested brood
currently are unknown.
s. Queens
from such VSH breeding sources can be allowed to mate freely with non-VSH drone
s, and the resulting hybrid colonies from these outcrosses
will retain lower and variable but generally still useful resistance to V. destructor while retaining desirable beekeeping
traits such as honey
production.
VSH outcrossed to commercial Italian bee
s recently have been shown to perform well in migratory cro
p pollination
.
VSH thus is a trait that can be used by breeder
s to mix with any type of desirable honey bee and is expanding resistance to V. destructor among diverse bee strains. VSH breeding material has been available through commercial sources since 2001.
Honey bee
Honey bees are a subset of bees in the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis...
s (Apis mellifera) in which bees detect and remove bee pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
e that are infested by the parasitic mite
Mite
Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...
Varroa destructor
Varroa destructor
Varroa destructor is an external parasitic mite that attacks honey bees Apis cerana and Apis mellifera. The disease caused by the mites is called varroatosis....
. V. destructor is considered to be the most dangerous pest problem for honey bees worldwide. VSH activity results in significant resistance to the mites.
Development
Bees with the trait were initially bred by the USDA Honey Bee Breeding, Genetics and Physiology Laboratory in Baton Rouge, LABaton Rouge, Louisiana
Baton Rouge is the capital of the U.S. state of Louisiana. It is located in East Baton Rouge Parish and is the second-largest city in the state.Baton Rouge is a major industrial, petrochemical, medical, and research center of the American South...
from colonies in which mite populations grew only slowly.
The factor causing slow mite population growth
Population growth
Population growth is the change in a population over time, and can be quantified as the change in the number of individuals of any species in a population using "per unit time" for measurement....
was found to be heritable
Heritability
The Heritability of a population is the proportion of observable differences between individuals that is due to genetic differences. Factors including genetics, environment and random chance can all contribute to the variation between individuals in their observable characteristics...
. The rate of mite population growth was found to be correlated with the reproductive rates of mites, resulting in naming the factor “suppressed mite reproduction” (SMR). It was subsequently discovered that the factor is founded on hygienic activity
Hygiene
Hygiene refers to the set of practices perceived by a community to be associated with the preservation of health and healthy living. While in modern medical sciences there is a set of standards of hygiene recommended for different situations, what is considered hygienic or not can vary between...
of adult bees, so SMR was renamed VSH.
VSH activity results in (1) an abnormally low proportion of mites that produce offspring within the population that remains in capped brood and (2) reduction of the brood infestation rate by greater than 70%. The specifics of how hygienic bees detect mite infested brood
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
currently are unknown.
Cross-breeding
Bees bred to have high levels of VSH tend to keep mite populations below thresholds recommended for treatment with pesticidePesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
s. Queens
Queen bee
The term queen bee is typically used to refer to an adult, mated female that lives in a honey bee colony or hive; she is usually the mother of most, if not all, the bees in the hive. The queens are developed from larvae selected by worker bees and specially fed in order to become sexually mature...
from such VSH breeding sources can be allowed to mate freely with non-VSH drone
Drone (bee)
Drones are male honey bees. They develop from eggs that have not been fertilized, and they cannot sting, since the worker bee's stinger is a modified ovipositor .-Etymology:...
s, and the resulting hybrid colonies from these outcrosses
Outcrossing
Outcrossing is the practice of introducing unrelated genetic material into a breeding line. It increases genetic diversity, thus reducing the probability of all individuals being subject to disease or reducing genetic abnormalities...
will retain lower and variable but generally still useful resistance to V. destructor while retaining desirable beekeeping
Beekeeping
Beekeeping is the maintenance of honey bee colonies, commonly in hives, by humans. A beekeeper keeps bees in order to collect honey and other products of the hive , to pollinate crops, or to produce bees for sale to other beekeepers...
traits such as honey
Honey
Honey is a sweet food made by bees using nectar from flowers. The variety produced by honey bees is the one most commonly referred to and is the type of honey collected by beekeepers and consumed by humans...
production.
VSH outcrossed to commercial Italian bee
Italian bee
Apis mellifera ligustica is the Italian bee which is a sub-species of the western honey bee .- Origin :The Italian honey bee is thought to originate from the continental part of Italy, South of the Alps, and North of Sicily...
s recently have been shown to perform well in migratory cro
Cro
Cro is an American animated television series produced by the Children's Television Workshop and Film Roman. It debuted on September 18, 1993 as part of the Saturday morning line-up for fall 1993 on ABC. Cro did not do well with the viewers...
p pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
.
VSH thus is a trait that can be used by breeder
Breeder
A breeder is a person who practices the vocation of mating carefully selected specimens of the same breed to reproduce specific, consistently replicable qualities and characteristics....
s to mix with any type of desirable honey bee and is expanding resistance to V. destructor among diverse bee strains. VSH breeding material has been available through commercial sources since 2001.