# Varroa Lure



## peletier (May 5, 2007)

Just read an article in "Bee Culture" where the author states "It is well known that Varroa mites are attracted to drone brood, because the longer developement time after capping.....gives the mated female mite more time to raise little mites." He cites "researchers" who put the mites' preference for drone brood at 8 to 10 times the rate for worker brood. "In other words, given a choice, the mite is far more likely to go into a drone cell than a worker cell."

The mite cannot know the projected development time of the brood it infests. If it is attracted to drone brood it is because of an "attractant".

If this is a fact, shouldn't some clever grad student be able to identify the attractant and create a lure which could be used to bait a trap which could then be BURNED with great celebration?:applause:


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## jmgi (Jan 15, 2009)

I always thought that mites preferred drone cells because of the larger cell size. It is my understanding that beekeepers regress their bees to get down to a cell size that is not attractive to mites.


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## RayMarler (Jun 18, 2008)

Some regress down to a smaller cell size to get smaller bees that have a higher metabolic rate which causes brood to hatch out a day earlier thereby thwarting the brooding cycle of the varroa, is my understanding.

Drone cell development is longer so is more attractive to the varroa, I don't know about the pheromone or attractant, but it sounds good. Varroa are in nature, raised to the top and side of a broodnest and are raised a degree or two lower temp than worker brood, which is more attractive to the varroa as well. I believe the temp for drone brood is more often 93F and for worker brood is 94 to 95F.


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## JBJ (Jan 27, 2005)

Drone brood and worker brood are different. They have been isolated and mites show a preference for drone brood pheromone over worker in the lab. There has been some research done using this biology to make a trap for mites, I think by Dr Caron. I have been toying with this idea for nearly a decade but have not had the resources or time necessary to put it together. There are some questions that come to mind. First what will happen and how will the bees respond to an abundance of drone brood pheromone? Will this upset the chemical ecology of the hive? Will the bees cease rearing drones if there is a perceived abundance of drones?

I would suspect that work in this area has stalled since a product has not come to market yet and it has been 4 or 5 years since I have seen a presentation on it. There has been one new pheromone product relatively recently; Mann Lake's Bee Boost. This is an example of how tinkering with the chemical ecology of the hive can produce strong affects in behavior and performance. We all depend on healthy drone populations so anything thing that may affect their numbers should be reviewed carefully.


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## peletier (May 5, 2007)

Thanks JBJ. I can accept pheromones doing the attracting. Couldn't buy mites predicting the development time of their host. 

Perhaps the drone pheomone could be placed OUTSIDE the hive. Trap those buggers before they get inside, or lure them to the outside. Just thinking outloud. I have no idea where one would get drone pheromone. Uh, may I do know. Messy.

This reminds me of my hippie organic gardening days back in the 70s. I made an insect repelent by "blending" a bunch of the critters to be repelled, adding water to make a spray, and applying it to the plants needing protection. The theory (not mine) was that the bugs didn't appreciate the smell of their own death, or something like that. In retrospect, it was probably hand-picking all those tomato worms off the plants to make the spray that had the greatest effect.


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## Michael Bush (Aug 2, 2002)

The research I've heard would indicate that they are BOTH attracted to the drone larvae (because they put drone larvae in worker cells and measured that infestation rate compared to workers in worker cells) and to the large cells (because they compared infestation rates of worker larvae in worker cells to worker larvae in drone cells). The actual answer is that it's some of both, cell size and some kind of smell that drone larvae give off. Other research seems to indicate that it's Juvenile Growth Hormone that they are smelling that drones make more of.

If you listen to Jennifer Barry's presentation on small cell on the HAS website she quotes some of these.


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## JBJ (Jan 27, 2005)

An extract of drone larvae and one of worker larvae can be made in the lab and tested. In the presentation I saw the mites nearly always moved toward the drone extract. The theory was that the extract contains semiochemicals that indicate where the best breeding and feeding is.

An interesting way to test the cell size hypothesis would be to reverse the extracts and place drone extract on worker cells and visa versa with worker larvae extract. I think the little red acarine vermin will move in the direction of the area that "smells" like an opportunity for the easiest food and reproduction. 

Further, Varroa tend to enter the cell after the larvae is present and emitting semiochems so I am skeptical on how much measuring they need to do to accomplish their mission, however Mom Nature always finds ways to surprise me.

MB could you post a link to JB's talk that you referred to?


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## Michael Bush (Aug 2, 2002)

http://www.heartlandbees.com/berry2007.htm


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