Post by Travers & Dianne on Sept 15, 2013 14:54:36 GMT -5
So we ( my wife Dianne and I ) bought a 3 lb. package of bees this spring. On the 24th of May a 24 hour sticky board counted 6 Varroa mites. On June 9th we found 16 mites per 24 hr period. On June 19th we layed one strip of hopguard over a brood chamber and dusted with powered suger. On July 2nd we found 7 mites within 24 hrs. Then Aug 1st counted 39 mites in 24 hrs. We are starting to worry at this piont. I installed one strip of hopguard per week for 3 weeks in a row. By Sep the 5th I counted 48 mites per 24 hrs. On the 8th of Sept I fogged the hive and the super with food grade mineral oil. We intend to fog once a week for three weeks. Do you think that we are wasting time fogging? Even better, what would you do with this hive on Sept 15th ?..... Thank You, Travers
I don't know the answer, but I figured I'd make a few calls. I spoke with Mr. Poling, and he said that Hop Guard only works when there is no brood present. He experimented with it a little, and said that he put bees in a jar. He applied Hop Guard, waited 6 hours, washed the bees, and many mites were still on the bees. Even when he increased the dosage to where the bees were practically gummed up, it basically just glued the mites to them.
He also said that the sugar really doesn't knock a lot of mites off if you're dealing with a breed of bee that is highly susceptible to mites. If it were him, he'd go with something like the Miteway2 quick strips.
He said that Apivar is also very good stuff. The FDA says it dissipates out of the comb, and while yes, it leaves a very small residue, the FDA feels it's nothing of any consequence.
He says fogger tends to only work on phoretic mites, and won't deal with any in the brood. He says foggers can help up to 98 percent of mites outside of the comb, but does nothing to help brood.
He felt that the colony, if not treated, could develop viruses, and that this colony is obviously susceptible to mites, and may require regular management of pests.
Nancy Ostiguy (Associate Professor of Entomology) from Pennsylvania State University says this:
All the data I've seen indicate that fogging with food grade mineral oil does not reduce the total mite load. If you open you colony and look at several frames the reduction in the number of mites will be the same as fogging.
The problem with both fogging and inspecting several frames is the only mites removed are adults. The most important mites in a colony are the one in the reproducing in the brood cells. This is why most of the materials (hopguard, Mite Away II, Apistan, Mite Check, etc) require the material be left in the colony for several weeks. The mites, when the emerge from the brood cells, are killed because the miticide is present for a long period of time.
To get your colony through winter, the most important thing is that the number of mites in the brood cells is small when the winter bees are being produced. Since winter bees began to be produced in August, you are already past the prime time to reduce the mite population in your colony.
It is hard to estimate what your mite population is with a 24 hour mite drop (see below). Assuming that your count is approximately the same as what a 7-day mite drop would produce, your colonies do not have excessive number of mites. [The daily fluctuation in the number of mites is large because it is completely dependent on the number of adults that emerge. Your 24-hour mite drop of 39 could be as low as 2 and as high as 70 on the days before and after your count. The most accurate way to estimate the daily mite drop is to count the total number of mites dropped on a sticky board over 7 days.]
An additional reasons to believe your mite population will not be sufficient to kill your colony is newly installed packages (1st year colonies) do not typically have enough mites to harm the colony by winter. Mites, because there is no bee brood, do not reproduce over winter. It is the second year of a colony's life that mite populations are typically high enough to kill a colony. [Keep in mind that I'm talking about probabilities. The risk is low but not non-existent that the mite population in a first year colony will be high enough to kill a colony.]
You should focus on making sure your bees have enough food to get through winter. Lack of food is more likely to kill a first year colony than mites.