''Varroa jacobsoni'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

mite Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...

that parasitises ''

Apis cerana ''Apis cerana'', the eastern honey bee, Asiatic honey bee or Asian honey bee, is a species of honey bee native to South, Southeast and East Asia. This species is the sister species of '' Apis koschevnikovi'' and both are in the same subgenus as ...

'' (Asian honey bees). The more damaging ''

Varroa destructor ''Varroa destructor'', the Varroa mite, is an ectoparasite, external parasitic mite that attacks and feeds on honey bees and is one of the most damaging honey bee pests in the world. A significant mite infestation leads to the death of a honey b ...

'' was previously included under the name ''V. jacobsoni'', but the two species can be separated on the basis of the

DNA sequence A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nu ...

of the cytochrome oxidase I gene in the

mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...

Biogeography

Prior to recent studies, ''V. jacobsoni'' was considered homogeneous; however, current research has detected genetic variance among populations by using genetic markers. This finding has led to the belief that ''V. jacobsoni'' was introduced to the Americas multiple times. The hosts switching between the eastern ''A. cerana'' and the western ''A. mellifera'' is the major factor that broadens the pathological transmission of ''V. jacobsoni''. It has spread worldwide with the exception of Australia and central Africa.

Evolution

At least 30 lineages of mites have specialised in living with bees. Most mite species associated with bee nests are either saprophagous or cleptophagous. Saprophagous mites eat hive debris, especially parts with fungi growth. Cleptophagous mites eat pollen and other nutrients stored by bees. The few that have evolved to become parasitic appear to have arisen from predatory lineages. The family Laelapidae has 12 genera that prey on stingless bees (Meliponinae). Thus, the brood parasites (Varroidae) of honeybees (Apinae) appear to have evolved from the Laelapidae.

Life cycle

The lifecycle of ''V. jacobsoni'' in ''A. cerana'' begins with a mature mated female entering a larval cell of a honey bee. Once the cell is capped, the adult female mite hides for five days inside the larval food near the bottom of the cell. After about five hours, the mite is released from the food, where it then begins feeding on the host's

haemolymph Hemolymph, or haemolymph, is a fluid, similar to the blood in invertebrates, that circulates in the inside of the arthropod's body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which hemolymph ce ...

. After 60 hours, the adult female mite lays its first egg on the wall of the cell. Unfertilised mite eggs produce male offspring, that are able to mate with the female offspring. The adult mated female then emerges from the cell with the emerging bee. Once mites are released to the environment, they are transferred to other bees through close contact. The adult female mites then feed through the intersegmental membrane on honeybee haemolymph. The cycle is then completed.

Chemical resistance to acaricides

Acaricide Acaricides are pesticides that kill members of the arachnid subclass '' Acari'', which includes ticks and mites. Acaricides are used both in medicine and agriculture, although the desired selective toxicity differs between the two fields. Termi ...

s are

pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

s that kill members of the

Acari Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as ea ...

group, which includes

tick Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...

s and

s. Acaricides were at one time an effective method in regulating the transmission of ''V. jacobsoni'' in honey bees, but the buildup of residues in acaricide-resistant strains have decreased the effectiveness of mite control in honey bees. Among those acaricides used are acrinathrin,

amitraz Amitraz (development code BTS27419) is a non-systemic acaricide and insecticideCorta, E., Bakkali, A., Berrueta, L. A., Gallo, B., & Vicente, F. (1999). Kinetics and mechanism of amitraz hydrolysis in aqueous media by HPLC and GC-MS. Talanta, 48(1 ...

, bromopropylate, chlordimeform,

coumaphos Coumaphos is a nonvolatile, fat-soluble phosphorothioate with ectoparasiticide properties: it kills insects and mites. It is well known by a variety of brand names as a dip or wash, used on farm and domestic animals to control ticks, mites, flie ...

flumethrin Flumethrin is a pyrethroid insecticide. It is used externally in veterinary medicine against parasitic insects and ticks on cattle, sheep, goats, horses, and dogs, and the treatment of parasitic mites in honeybee colonies. Chemistry Flumethrin ...

, and

fluvalinate Fluvalinate is a synthetic pyrethroid chemical compound contained as an active agent in the products Apistan, Klartan, and Minadox, that is an acaricide (specifically, a miticide), commonly used to control varroa mites, ''Varroa'' mites in honey ...

. Fluvalinate is the most effective acaricide.

Images

File:Varroa jacobsoni ventral view.jpg, ventral view File:Varroa jacobsoni Dorsal closeup.jpg,

Dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

(closeup) File:Varroa jacobsoni Mouthparts closeup.jpg, Mouthparts (closeup) Naturalis_Biodiversity_Center_-_RMNH.ART.1176_-_Varroa_jacobsoni_(Oudemans)_-_Mites_-_Collection_Anthonie_Cornelis_Oudemans.jpeg, Female of Varroa jacobsoni by A.C. Oudemans.

References

{{Authority control Mesostigmata Agricultural pest mites Animals described in 1904 Taxa named by Anthonie Cornelis Oudemans Arachnids of Japan