October 11, 2016

Icing or Powdered Sugar for Varroa Control

The use of powdered sugar dusting is a popular non-chemical approach to the control of varroa mite in honey bee colonies and is seen as an effective integrated pest management control (that is, one that does not rely on chemical intervention but good management practices.)

The method has proved to be an effective means of reducing varroa mites in honey bee colonies, having a significant impact on mite reproduction. When the bees are covered with powdered sugar their bodies become slippery causing the varroa to lose their ability to cling to the bees, the granules of sugar interfere with the gripping surfaces of the varroas’ feet and they fall to the floor of the hive.

The powdered sugar also causes the bees to groom themselves more frequently causing more mites to be dislodged. This technique does not appear to have any adverse effect on adult bees or brood.  Unlike chemical methods this technique can be used at any time, even during a honey flow, as it does not contaminate the honey and as frequently as needed to control the mite. It can also be used as a method for detecting and assessing varroa mite infestation, within a colony.

How to apply powdered sugar to your honey bee colony

Take a sugar (or cocoa) shaker like the one pictured and use approximately 125 grams (1 cup) of sugar per single hive box. You should either have an open mesh floor or a sticky board in place, as the sugar does not kill the varroa but merely dislodges them. If not caught or dropped through a mesh floor the varroa will simply climb up into the frames again.

Smoke the colony as usual and put the sticky board in place on the hive floor if you are using one. Smoke the bees down from the top boxes. Remove the boxes and apply the sugar to the bottom box first, working up through the boxes. There is no need to remove the frames from the hive. Sift or dust the powdered sugar over the top bars of the frames and into the bees in the seams. Using a bee brush carefully brush the powdered sugar from the tops of the frames to between them.

The frequency with which you will need to apply this treatment will depend upon the level of varroa mite infestation.

The only down side to the use of powdered sugar for varroa control is if not used carefully it could potentially increase the chances of robbing by other bee colonies, during a nectar dearth and may also encourage ants. Even if you have an open mesh floor it is a good idea to apply a sticky board underneath to catch the sugar, this will also enable you to monitor the level of infestation in your hive.

Sticky boards can be purchased or made from cardboard or thick paper thinly smeared with a sticky substance such as vegetable oil or Vaseline.

More About Colony Management

Russian Hybrid Honey Bees

Russian Hybrid Honey Bees are one of the newer bee stocks in the U.S. The Department of Agriculture’s Honey Bee Breeding, Genetics and Physiology Laboratory in Baton Rouge, Louisiana have produced queens derived from bees found on the far eastern side of Russia in the coastal Primorski region on the Sea of Japan and around Vladivostok.

The researchers’ logic was that these Russian Bees have coexisted for the last 150 years with the devastating ectoparasite Varroa destructor, a mite that is responsible for severe colony losses around the globe. Moreover, they are also highly resistant to tracheal mites, the other major enemy of honey bees here in the West. While these bees are much more expensive than other strains and require special management techniques, they may be the only answer to the Varroa problem. Such stock very importantly also provides a chemical free alternative to pest control.

The USDA tested whether this stock had evolved resistance to varroa and found that it had, with numerous studies showing that bees of this strain have fewer than half the number of mites that are found in standard commercial stocks.

Russian Hybrid bees also tend to rear brood only during times of nectar and pollen flows, so brood rearing and colony populations tend to fluctuate with the environment, thereby suiting them better for areas with more severe and longer winters.

Russian Hybrid Bees also exhibit some unusual behaviour compared to other strains. For example, they tend to have queen cells present in their colonies almost all the time, whereas most other stocks rear queens only during times of swarming or queen replacement. Russian Hybrid bees also perform better when not in the presence of other bee strains as research has shown that cross-contamination from susceptible stocks can lessen the varroa resistance of these bees.

More about Honey Bee Hybrids and Strains

The Varroa Mite Life Cycle Inside a Honey Bee Colony

One of the most widespread problems for beekeepers around the world is the mite known as Varroa destructor, previously known as Varroa jacobsoni. The varroa mite originated in Southeast Asia where it is a parasite of the Eastern honey bee, Apis cerana and was first discovered on the western honey bee, Apis mellifera, in 1960. It is thought that these pests came into the United States and Europe through illegally imported queens in the 1980′s and have since then had a devastating effect on some beekeeping operations.

Varroa mites are about the size of a pin head and are copper in colour, crab- shaped, with eight legs to the front and wide oval-shaped bodies. Female mites cling to the adult bees’ abdomen and feed off their haemolymph (blood). They do this by piercing the membrane between the plates of the bee’s abdominal segments. Although small, a varroa female is one of the largest ectoparasites (i.e lives outside the host body) known when considered in relation to the size of its host.

The female will enter a brood cell on a hive frame containing a larva and crawl underneath it, then hidden under the larval jelly she waits until the cell is capped. The female varroa mite then lays an egg every thirty hours. The first egg laid will be a male, with subsequent eggs being female. The maturing mites will feed on the bee pupa often causing developmental problems, such as wing damage.

The male egg develops into an adult in five to six days and a female in seven to eight. The male mates with his adult sisters and once the cell is uncapped and the bee emerges, the mature fertilized female varroa will leave the cell. The male varroa who never eats and any undeveloped females are left behind to die.

The mated females live on the young host bee until they enter cells to reproduce. In the summer varroa mites can live for about two-three months but survive for much longer in the winter. In summer mites usually manage two reproductive cycles which can produce eight daughters if using drone (male bee ) brood.

Developing female worker honey bees remain in a capped cell for twelve days and drones remain for fourteen days. Therefore more mites are able to reproduce in a drone cell than a worker cell and the female mite for this reason will actively seek out drone cells to lay her eggs. It has been calculated that a single varroa mite laying in a worker cell will result in 1.8 mites emerging with the adult bee compared to 2.8 mites from a drone cell.

If infestation is left unchecked the colony will die out within three to five years. As the adult honey bees within the colony become weakened and have reduced life-spans, the normal hive routine will be disrupted which leads to poor hygiene, leading in turn to bacterial and viral diseases thriving.

by Maggie Roberts

To learn more about beekeeping see http://www.beekeepingbeesandhoney.com/