Varroa destructor, a parasite that originally a parasite on the Indian bee Apis Cerana. Varroa is present in all stages of the bee growth. Varroa females survive the winter and in the spring together with the bees move into a new growth cycle. Unfertilized females of parasites as well as males live only in closed cell honeycomb. Varroa destructor feeds Hemolymph and can in a short period completely destroy bee colonies. Although the Varroa parasite has been detected during the early 20th century, the first time he has been noticed on the bees was in Japan in 1958. In Europe, the natural expansion coming in 1980., and in South America was imported from Japan in 1971.
Varroa destructor is mite that can be seen on bees and bee brood. Males are pale yellow in color, size 0.9 mm. Males have only breeding function and live only in covered honeycomb cells and don’t suck the hemolymph. After mating die. Females are larger, measuring 1.5 x 1.8mm, dark brown and suck the hemolymph. They have four pairs of legs. Attacks usually drone brood. Most mites is on the young bees and drones. The female can live for 2-3 months and 6-8 months in the winter. Varroa very bad tolerates high temperatures and temperatures of 42C – 44C kills parasites in a few minutes.
Development of disease
Varroa feeds Hemolymph and thus shortens the life of bees and eventually kills the whole colony. Also reduces its immunity and vitality. The disease is spread by direct contact diseased bees with healthy bees, trading bees, beekeeping equipement, bees migrations, etc.
It should be mentioned that some species of bees have achieved a high degree of immunity to Varroa destructor as so called Africanized honey bees from South America. More cases of dying bees in infected communities can be observed in late autumn, during the winter or in early spring. If there is more than 2000 mites in one colony it is highly infected colony. If in the early winter (month of December) at number of 100 bees in the observed sample found more than 5% of those infected is considered a serious degree of infection, and all above 9% very severe degree of infection, colony with 9% with no additional treatement is hard to expect will survive the winter.
How to cure
Drones’ brood is a great source of infection. Certain contribution to combating disease lays in partially destroying of the drone brood. In some parts of the world (Russia) carried out thermal treatment, as well as an excellent method, but requires expensive equipment. There is a whole list of drugs that treat bee colonies in the fight against this disease, with more or less success. The medicine treatment require beekeepers responsibility and not their application in honey season. The medicine treatment is possible in early autumn to early winter period, fortunately it is the best part of year for Treatment of Varroa destructor. Very important is the constant control of honey bee colonies, against this treacherous and very dangerous disease that can develop and very quickly kill entire bee colony. Decision how and when do a Treatment of Varroa destructor allways has to based on personal experience, experience of other beekeepers, literature sources, local and national experts advice and the advice of local beekeepers associations.