Varroa Mite

Western honey bees are in danger: Beekeepers have been reporting massive bee losses for several years.

One of the main causes of these losses is the varroa mite. In the past, efforts to control this parasite have concentrated exclusively on treatment in the hive, but foraging bees then bring back new mites when they return home. Bayer’s scientists have been working with bee researchers from Frankfurt University to develop the varroa gate, which is designed to prevent reinfection. This innovative front door should effectively protect the hive against the deadly parasite.

Life in the hive is highly organized, with busy insects working all around the queen. Worker bees distribute pollen, clean and look after larvae, or defend the entrance against enemy invaders like wasps and other honey thieves. But the varroa mite, Varroa destructor, slips in unnoticed on the bodies of some worker bees, evading the strict door policy. It brings a deadly danger with it; this tiny, brown arachnid can wipe out entire bee colonies. Like a tick, it fastens itself onto a bee with its jaws and so sneaks its way into the realm of the hard-working nectar collectors. Once inside, mites reproduce by laying their eggs in the honeycombs where new bees are raised. After ten to fourteen days their offspring spread throughout the bee population along with the newly emerged bees.  (Text: Bayer Beecare)

Varroa mites transmit dangerous viruses and bacteria

Varroa mites transmit pathogens like viruses and bacteria which are damaging to bee health. This parasite has wiped out entire populations of Western honey bees over recent years. Without human intervention, infestation with varroa means certain death sooner or later for honey bees in Europe and America. Things are different in Asia, where the deadly mite originated. There, a balanced relationship between the parasite and its original host, the Eastern honey bee or Apis cerana, has evolved over many generations.

A new way of protecting bees against varroa mitesThe varroa mite was not seen in Europe until the 1970s and in America until the 1980s, but since its introduction it has caused massive bee deaths, as the Western honey bee has no defense against the parasite.

This was a disaster not just for beekeepers: in most countries honey bees are the main pollinator of crops such as apples, oilseed rape and almonds. In Europe, they are therefore regarded as the third most important domesticated animal after cattle and pigs. (Text: Bayer Beecare)

Varroa watch list

  • Examine hive floor debris for mites – purpose-made varroa floors with screens help.
  • In heavy infestations, mites can be seen on adult bees, on wax combs and in cells.
  • As varroa is more attracted to drone brood than workers uncapping and examining samples of drone brood may be used as a diagnostic tool for varroa infestation.
  • A sudden crash in adult bee numbers may be an indication of varroa.
  • Bees with twisted or shrivelled wings, small abdomens or other deformities may be the result of varroa plus viral infections.
  • Poor general colony health and irregular brood pattern may be attributed to varroa plus attack by other disease organisms (viruses, bacteria, fungi) sometimes referred to as Parasitic Mite Syndrome or PMS.
  • Diagnostic treatment of the honeybee colony may be performed with approved acaricides and methods.
    (by Vita Europe)