Varroa Mites

Varroa Mites#

1 . When were varroa mites introduced into the United States?

1987

2 . What is the most damaging pest of the western honey bee in the world today?

Varroa destructor, Varroa mite

3 . There are a number of viruses that infect a colony, name a few?

Deformed wing virus (DWV), Kashmir bee virus, Chronic bee paralysis, Sacbrood, Israeli acute paralysis virus

4 . Are viruses in colonies associated with any other parasite?

Yes, Varroa destructor.

5 . Are there IPM management options to control viruses in our colonies

No, but controlling of varroa can indirectly help control viruses

6 . Is Varroa destructor a natural host of Apis mellifera?

No. It is a natural parasite of Apis cerana (eastern honey bee) in which damage is limited to drones and has minimal impact on their colonies. The introduction of Apis mellifera (western honey bee) into eastern Asia provided varroa the ability to jump hosts. This has led to devastating impacts for bees and beekeepers.

7 . When does the life cycle of varroa begin in the colony?

A gravid female mite enters a worker or drone brood cell and buries herself under the larva. When the larva is capped and stretches into prepupal phase, the female mite moves onto the abdomen of the pupa, opens a food port and begins to lay eggs. The first egg to hatch is the male and subsequent eggs are females. The adult mite and developing young feed upon the larva. The female mites mate with the male mite and will emerge as an adult alongside the drone or worker bee.

8 . When is the damage from varroa most severe? Why?

Late season as the brood area is declining and a large number of mites begin to compete for a shrinking amount of brood

9 . Describe how to use a “sticky sheet/board” to determine treatment thresholds for varroa?

  1. Coat it with a thin layer of Vaseline and place it below the bottom board under #8 hardware cloth and count varroa mites caught in 24 hours.

  2. Purchase sticky sheets that have been treated with material to adhere varroa to the board

10 . Describe methods of IPM management to control varroa:

  1. Biological – there really are no proven biological methods for controlling varroa

  2. Cultural – screened bottom boards, brood cycle disruption, drone brood trapping

  3. Genetic – Hygienic, VSH, grooming - ankle bitters, Russians, survivors

  4. Chemical – Oxalic & Formic acid, Essential oils Api-Life Var (thymol eucalyptus, and menthol) & Apiguard (thymol), Apistan (fluvalinate), HopGuard (hops beta acids), Apivar (amitraz), Checkmite (coumaphos)