To Bee Or Not To Be Honey
Varroa Mites
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These little critters suck, quite literally
The varroa mite appears to have been introduced to the United State in 1987 (although some literature mentions seeing mites earlier) through improper (illegal) importation of bees to Florida despite a legal quarantine which had been in place for a long time. The mites were identified after some hives were transported from Florida to Wisconsin and colony failures occurred. Checks around the nation found that the mites were already in a dozen states. Originally the mites were identified as Varroa Jacobsoni, later ast DNA testing became more available the mites were identified as Varroa Destructor (A much more destructive species).
Varroa mites originated from Asia. Asia bees have adapted over thousands of years to live with these mites. However the bees found in the US (and many other countries of the world) originated in Europe and they have little to no defense mechanisms against these mites. Similar to the introduction of small pox into America, varroa is devastating to European bees.
Varroa mites originated from Asia. Asia bees have adapted over thousands of years to live with these mites. However the bees found in the US (and many other countries of the world) originated in Europe and they have little to no defense mechanisms against these mites. Similar to the introduction of small pox into America, varroa is devastating to European bees.
Many beekeepers ignored the warnings from the regulatory agencies for years, not understanding what the impact would be (losing many colonies). The mites spread across the continent quickly as many beekeepers migrate their bees across the nation to pollinate crops in across the continent.
Prior to the infestation a lot of pollination was performed by feral colonies as well as managed colonies. Once beekeepers started treating for mites with miticides their colonies became stronger. Once the infestation took hold, many of the feral colonies started to weaken and be robbed out by stronger managed colonies. Then the robbing bees would return with more and stronger mites to the managed hive creating a vicious cycle that was producing mites that could not be killed with the miticides previously used.
The number of productive colonies in the US fell from 4.25 million in 1998 to less than 2.5 million hives in 2007 where a new threat was identified as Colony Collapse Disorder (CCD) which is a topic for another article.
Over the years beekeepers have recognized the very real threat this beast has produced. Many are actively involved in research to overcome the problem. Some are trying to breed better genetics into the bees, but considering new imports are banned (for good reason) they have to work with only the genetics that are in the states already. Some are working on better treatments to kill the mites. Many of these work well at first but eventually fail because the mites that live carry on genetics which make them resistant to the treatments.
The adult mites suck, quite literally, they suck the fat body (which serves much the same purpose as blood in humans) from adult bees and the larvae. This weakens the bees and leads to their death. A larger issue is that the mites also spread other diseases to the bees (viruses and bacteria). One such disease paralyzes the flight muscles of bees, another turns the developing larvae into a foul goo that spread through the hive and destroys it.
Prior to the infestation a lot of pollination was performed by feral colonies as well as managed colonies. Once beekeepers started treating for mites with miticides their colonies became stronger. Once the infestation took hold, many of the feral colonies started to weaken and be robbed out by stronger managed colonies. Then the robbing bees would return with more and stronger mites to the managed hive creating a vicious cycle that was producing mites that could not be killed with the miticides previously used.
The number of productive colonies in the US fell from 4.25 million in 1998 to less than 2.5 million hives in 2007 where a new threat was identified as Colony Collapse Disorder (CCD) which is a topic for another article.
Over the years beekeepers have recognized the very real threat this beast has produced. Many are actively involved in research to overcome the problem. Some are trying to breed better genetics into the bees, but considering new imports are banned (for good reason) they have to work with only the genetics that are in the states already. Some are working on better treatments to kill the mites. Many of these work well at first but eventually fail because the mites that live carry on genetics which make them resistant to the treatments.
The adult mites suck, quite literally, they suck the fat body (which serves much the same purpose as blood in humans) from adult bees and the larvae. This weakens the bees and leads to their death. A larger issue is that the mites also spread other diseases to the bees (viruses and bacteria). One such disease paralyzes the flight muscles of bees, another turns the developing larvae into a foul goo that spread through the hive and destroys it.
The mites have a 10 day life cycle (not life span) which goes something like:
- A Female mite finds a cell that is just about ready to be capped, sneak in and hide behind the larvae
- Once capped the mite will lay several eggs on the larvae, one male the rest female.
- The mite hatch in the cell before the larvae (now technically a pupae) emerges.
- The male will mate with the female (yup they have no problem with incest those unholy beasts)
- The female will emerge with the host and feed and start the cycle again.
Currently there are several treatments being used. Most are chemicals that target some aspect of the mites physiology that does not target the bees, but considering that they are both exoskeleton based life forms that is tough.
The most common treatment currently use acids such as formic acid or oxalic acid. Formic acid is most effective, but has very strict temperature ranges where it is not harmful to the bees, below the range and it is not effective, and above the range and it will kill the bees. It has a benefit of being able to kill mites under the capped cells. Many beekeepers are afraid to use it because it is really hard on the bees. Oxalic acid (wood bleach) is also very effective (although the science is not clear why yet but it looks like the mites absorb it in their sticky feet and die). It is gentler on the bees and not sensitive to temperature, but it involves more work as it is administered in either a drip or a vapor, and since it does not kill mites in the capped cells it must be applied several time to get all the mites in the colony..
The most common treatment currently use acids such as formic acid or oxalic acid. Formic acid is most effective, but has very strict temperature ranges where it is not harmful to the bees, below the range and it is not effective, and above the range and it will kill the bees. It has a benefit of being able to kill mites under the capped cells. Many beekeepers are afraid to use it because it is really hard on the bees. Oxalic acid (wood bleach) is also very effective (although the science is not clear why yet but it looks like the mites absorb it in their sticky feet and die). It is gentler on the bees and not sensitive to temperature, but it involves more work as it is administered in either a drip or a vapor, and since it does not kill mites in the capped cells it must be applied several time to get all the mites in the colony..
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