Last updated
THYMOVAR Thymovar.jpg

THYMOVAR is a product to control the Varroa mite (Varroa destructor) on bees ( Apis mellifera ) and contains the essential oil thymol.

<i>Varroa destructor</i> species of arthropods

Varroa destructor is an external parasitic mite that attacks the honey bees Apis cerana and Apis mellifera. The disease caused by the mites is called varroosis.

Essential oil hydrophobic liquid containing volatile aroma compounds from plants

An essential oil is a concentrated hydrophobic liquid containing volatile chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetherolea, or simply as the oil of the plant from which they were extracted, such as oil of clove. An essential oil is "essential" in the sense that it contains the "essence of" the plant's fragrance—the characteristic fragrance of the plant from which it is derived. The term essential used here does not mean indispensable as with the terms essential amino acid or essential fatty acid which are so called since they are nutritionally required by a given living organism. In contrast to fatty oils, essential oils typically evaporate completely without leaving a stain or residue.

Thymol chemical compound

Thymol (also known as 2-isopropyl-5-methylphenol, IPMP) is a natural monoterpenoid phenol derivative of cymene, C10H14O, isomeric with carvacrol, found in oil of thyme, and extracted from Thymus vulgaris (common thyme) and various other kinds of plants as a white crystalline substance of a pleasant aromatic odor and strong antiseptic properties. Thymol also provides the distinctive, strong flavor of the culinary herb thyme, also produced from T. vulgaris.


THYMOVAR contains thymol, a volatile substance which sublimates in the air depending on temperature. On release, thymol vapour concentrations build up in the treated beehive. These vapours are highly toxic to varroa mites but concentrations are not high enough to harm the honey bees. For optimal control, appropriate concentrations of thymol vapour must be maintained for six to eight weeks.



THYMOVAR - Uses Thymovar 1.jpg

Best efficacy is achieved when maximum daytime temperatures are between 20 °C and 25 °C throughout treatment. Reduced

product efficacy occurs if average temperatures fall below 15 °C during the treatment. Do not apply if outside temperatures exceed 30 °C. Treatment at temperatures in excess of 30 °C leads to increased stress and mortality of adult bees and brood.

Time of treatment

The best time for THYMOVAR treatment is as soon as possible after the last honey harvest in late summer at recommended temperatures. Treat all hives in an apiary at the same time to avoid robbing behaviour.


Prior to THYMOVAR treatment, remove all honey supers, close or replace open or screened hive floors with solid floors, and reduce the hive entrances to normal size. It is recommended that part of the feeding is carried out before the treatment, if the infestation of varroa and the temperatures allow.

Begin the 1st application of a treatment by placing appropriate number of bee-hive strips (positions shown in Fig. 1) on top of combs of the brood chamber (upper brood chamber if two). Bee-hive strips should be close to, but not directly over open or sealed brood (preferable distance > 4 cm). Close the hive, leaving space (about 5 mm) between the bee-hive strips and the hive cover to improve the evaporation of thymol. Do not place plastic cover foils directly on the bee-hive strips. Remove the 1st set of depleted THYMOVAR wafers after 3–4 weeks.

Begin the 2nd application immediately with a new set of bee-hive strips in appropriate numbers and positions, as shown in Fig. 1. Remove these bee-hive strips when they are depleted at the end of the 2nd 3-4 week application period.

Concept of Control

A combined application of THYMOVAR with an oxalic acid treatment in the broodless time (November - December) has proved very efficient against the Varroa.

Oxalic acid simplest dicarboxylic acid

Oxalic acid is an organic compound with the formula C2H2O4. It is a colorless crystalline solid that forms a colorless solution in water. Its condensed formula is HOOCCOOH, reflecting its classification as the simplest dicarboxylic acid.

See also

Through voltilisation, thymol vapour concentrations build up in the hive. These are highly toxic to the varroa mites, but do not harm the bees. Detailed information can be found at Andermatt BioVet AG. [1] [2]

Related Research Articles

Beehive enclosed structure in which honey bees live and raise their young

A beehive is an enclosed, man-made structure in which some honey bee species of the subgenus Apis live and raise their young. Though the word beehive is commonly used to describe the nest of any bee colony, scientific and professional literature distinguishes nest from hive. Nest is used to discuss colonies which house themselves in natural or artificial cavities or are hanging and exposed. Hive is used to describe an artificial, man-made structure to house a honey bee nest. Several species of Apis live in colonies, but for honey production the western honey bee and the eastern honey bee are the main species kept in hives.

Beekeeping care and breeding of honey bees

Beekeeping is the maintenance of bee colonies, commonly in man-made hives, by humans. Most such bees are honey bees in the genus Apis, but other honey-producing bees such as Melipona stingless bees are also kept. A beekeeper keeps bees in order to collect their honey and other products that the hive produce, to pollinate crops, or to produce bees for sale to other beekeepers. A location where bees are kept is called an apiary or "bee yard."

Bee brood

In beekeeping, bee brood or brood refers to the eggs, larvae and pupae of honeybees. The brood of Western honey bees develops within a bee hive. In man-made, removable frame hives, such as Langstroth hives, each frame which is mainly occupied by brood is called a brood frame. Brood frames usually have some pollen and nectar or honey in the upper corners of the frame. The rest of the brood frame cells may be empty or occupied by brood in various developmental stages. During the brood raising season, the bees may reuse the cells from which brood has emerged for additional brood or convert it to honey or pollen storage. Bees show remarkable flexibility in adapting cells to a use best suited for the hive's survival.

Drone (bee) male bee, wasp or hornet

A drone is a male bee. Unlike the female worker bee, drones do not have stingers and gather neither nectar nor pollen. A drone's primary role is to mate with an unfertilized queen.

Italian bee subspecies of the western honey bee (Apis mellifera)

Apis mellifera ligustica is the Italian bee which is a subspecies of the western honey bee.

Hive frame structural element in a beehive

A hive frame or honey frame is a structural element in a beehive that holds the honeycomb or brood comb within the hive enclosure or box. The hive frame is a key part of the modern movable-comb hive. It can be removed in order to inspect the bees for disease or to extract the excess honey.

Swarming (honey bee) process by which a new honey bee colony is formed

Swarming is the process by which a new honey bee colony is formed when the queen bee leaves the colony with a large group of worker bees. In the prime swarm, about 60% of the worker bees leave the original hive location with the old queen. This swarm can contain thousands to tens of thousands of bees. Swarming is mainly a spring phenomenon, usually within a two- or three-week period depending on the locale, but occasional swarms can happen throughout the producing season. Secondary afterswarms may happen but are rare. Afterswarms are usually smaller and are accompanied by one or more virgin queens. Sometimes a beehive will swarm in succession until it is almost totally depleted of workers.

<i>Varroa jacobsoni</i> species of arthropods

Varroa jacobsoni is a species of mite that parasitises Apis cerana. The more damaging Varroa destructor was previously included under the name V. jacobsoni, but the two species can be separated on the basis of the DNA sequence of the cytochrome oxidase I gene in the mitochondrial DNA.

Deformed wing virus species of virus

Deformed wing virus (DWV) is an RNA virus, one of 22 known viruses affecting honey bees. While most commonly infecting the honey bee, Apis mellifera, it has also been documented in other bee species, like Bombus terrestris, thus, indicating it may have a wider host specificity than previously anticipated. The virus was first isolated from a sample of symptomatic honeybees from Japan in the early 1980s and is currently distributed worldwide. It is found also in pollen baskets and commercially reared bumblebees. Its main vector in A. mellifera is the Varroa mite. It is named after what is usually the most obvious deformity it induces in the development of a honeybee pupa, which is shrunken and deformed wings, but other developmental deformities are often present.

Western honey bee species of insect

The western honey bee or European honey bee is the most common of the 7–12 species of honey bee worldwide. The genus name Apis is Latin for "bee", and mellifera is the Latin for "honey-bearing", referring to the species' production of honey.

Fluvalinate chemical compound

Fluvalinate is a synthetic pyrethroid chemical compound contained as an active agent in the products Apistan, Klartan, and Minadox, that is an acaricide, that is commonly used to control varroa mites in honey bee colonies, infestations that constitute a significant disease of such insects.

Coumaphos chemical compound

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, flies and fleas.

Beekeeping in the United States

Beekeeping in the United States dates back to the 1860s.

Colony collapse disorder sudden extinction of bee colony

Colony collapse disorder (CCD) is the phenomenon that occurs when the majority of worker bees in a colony disappear and leave behind a queen, plenty of food and a few nurse bees to care for the remaining immature bees. While such disappearances have occurred sporadically throughout the history of apiculture, and were known by various names, the syndrome was renamed colony collapse disorder in late 2006 in conjunction with a drastic rise in the number of disappearances of western honey bee colonies in North America. Most European countries observed a similar phenomenon since 1998, especially marked in Belgium, France, the Netherlands, the UK, Greece, Italy, Portugal, and Spain, Switzerland, Germany and the Northern Ireland Assembly received reports of a decline greater than 50%. The phenomenon became more global when it touched some Asian and African countries too.

<i>Apis cerana japonica</i>

Apis cerana japonica is a subspecies of the eastern honey bee native to Japan. It is commonly known as the Japanese honey bee. This subspecies was determined, through an analysis of mitochondrial DNA, to have originally come from the Korean peninsula. They have been observed moving into urban areas in the absence of natural predators.

Varroa sensitive hygiene (VSH) is a behavioral trait of honey bees (Apis mellifera) in which bees detect and remove bee pupae 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.

Beekeeping in Ireland has been practiced for at least 2000 years and has seen a surge in popularity in modern times, evidenced by the numerous organizations promoting and assisting beekeeping. Despite the increased pressures on bees and beekeepers through new diseases and loss of habitat there are now in excess of 3,500 members within beekeeping associations.


  1. Andermatt BioVet AG: Andermatt BioVet AG