September 23, 2010
Adult wax moth carcasses often litter the bottom of a hive. Take a look through this gallery for some close-ups of the mite, the wax moth larva and pupa.
submitted by J. Morgan
There's a lot of information that can be gained by taking a closer look at something we might usually disregard. Particularly, the boards on the bottom of our bee hive. Listen to me... I have screen bottom boards in the bottoms of my hives... so what am I talking about?
Today, I paid another visit to Jim and Cindy's apairy for a hands-on look at some of the fodder that falls to the bottom of the hive. Call it a lunch date with a bee, a mite and a wax moth if you will. Anyway, at first glance, the bottom board looks quite disgusting. Just look at all those crunchies on it. After a closer second look, I'm thinking about the crust I put on top of my zucchini casserole. Mmmmm.
But really, there's more to be gained here than the next recipe idea. Were talking about determining if and when we should take action against the parasites that inhabit our hives. Varroa mites, in small numbers may not be reason enough for concern, but if we noticed a climb in these numbers, what would we do? How many is too many? Are we really looking anyway? These are the questions whose answers are many. Ever notice you can't get a straight answer out of someone when you ask? Usually, it's because it may vary from one area to another. Or perhaps one beekeeper has a particular threshold before they worry about mites. Maybe one hive is more hygenic than another.
Here's how Jim and Cindy do it. Take a look at this image. Jim has drawn a line across the width of his board and he and Cindy count the mites on one half of the board. Read below as Cindy describes when they will take action.
"We will count 100 mites over a one day drop on an average-sized two-story beehive. When we have a really huge hive, that number might be bigger. When we have a small, one-story hive, it's lower. The last couple years, I've been doing a 2-3 day drop count, and dividing to get a daily average. I think this gives you a truer count. You also want the count to be over a period of time when you are not in there thrashing around and stirring things up. We usually scrape the sticky boards after we are done in the apiary, then 2-3 days later, I go out, count and get my average daily drop."
This advice to me is good for my own basis. I will do this until there's a more compelling reason to change it. How we take action against mites is determined by our beliefs on what should and shouldn't go in to a hive. Most of our members employ more natural approaches. Some may be strict about this, while others may actually submit to chemicals. Here are three more natural approaches to mite control listed from least to most effort; tobacco smoke (arguably, less-natural,) Sugar dusting, or the Mel Disselkoen outbreeding approach. Don't let the complexities of the appraoch discourage you. We only want to share this information to better arm you for when you may need to take action. I'm in my first year hives and I have not found a mite yet. I have however found wax moth larva and a few hive beetles. None seem to have affected the productivity of either hive.
Click the image above to view the gallery of images I took between Jim's and my own hives. Hopefully, the images will help new beekeepers identify mites and wax moth larva as well give an indication of their relative size. I'll follow up on this blog with more details and I uncover them but I'm hoping a few more seasoned beekeepers will chime in on some information to add. More later.
September 19, 2010
submitted by J. Morgan
There's a lot of opinions and thoughts on sugar dusting and so on Thursday, September 16, 2010, we decided to address the topic. The associated video was our attempt to further explain and demonstrate the matter. Techniques and thoughts vary depending on who you ask or the area you are in. We hope this video is helpful to you.
What is sugar dusting?
It is a technique that Dr. Fakhimzadeh proposed as a part of his Doctoral work and is published in several journals. Google his name to find out more.
The idea is simple. Varroa have little "suction-cup" feet. When varroa fall down below a varroa screen or out a screen bottom board, they don't crawl back up. Sugar particles that are approx. 5 microns in diameter (powdered sugar or "dust") clog up the mites suction cups, and they can't hang on to the bees so they fall and eventually die and don't live to reproduce. Therefore, dusting the bees will knock off some significant percentage of the mites, keeping the population under control.
Sugar dusting may allow you to stop using Apistan strips or other toxic treatments. This treatment is both cheap and non-toxic treatment so we like it and want to explore it. Most of our club members tend to lean towards more natural beekeeping and there are many methods of mite management to choose from. See Mel Disselkoen's outbreeding mites and overwintering honey bees.
What powdered sugar to use
Thoughts are... 2% - 5% corn starch (found in Domino 10X and most other store brands) doesn't matter one bit. But it doesn't hurt to try to find the LOWEST percentage of corn starch you can.
Supposedly, "pure" powdered sugar with zero corn starch (added to keep it from clumping) exists. If you can find it, great.
Preparing the sugar
It's the very tiny sugar particles that clog up the "suction cups" on the legs of the varroa mites. But how to insure that you "dust" a minimal amount of useless larger particles, when the optimal particle size is on the order of 5 microns?
- We sifted the sugar the day I used it but you can do it ahead of time if you store it right.
- First, all sugar is sifted with a flour sifter. This removes the big lumps.
- Sift the sugar again right in to a container that you can seal tightly from moisture.
- Adding some rice to your sugar container can absorb humidity, and keep the sugar drier.
- Seal the container tightly, (canning jars work).
Note submitted by Kenny Schneider: Use powder sugar with the least amount of corn starch. I make my own powder sugar. Just put your regular sugar in a blender and in a few seconds you have powder sugar with no corn starch.
Sugar application to the hive
Application of the sugar is your choice. There are many options and whatever one can give you full coverage with less effort is good. As you see in the video, we used both a bellowed blower and a flour sifter. There are "pistols, foot-pumps and you could even use a dried baby-powder container, (where you can twist the cap to reveal tiny holes.) Again, the most important thing is that you cover all the bees. In our video, we didn't go frame by frame. Obviously doing so would give you the best coverage, but it's a huge disturbance to the hive.
Dust the bees trying not to get too much on the comb. There is a lot of debate about dusting. Some mentioned simply dusting the top bars rather than removing the frames, but the idea here is to do your best to knock down all the adult varroa in the hive.
If you google "Dr. Fakhimzadeh" you will see he says that sugar DOES NOT have a negative effect on open brood or eggs. It's said that OTC dusted with sugar was claimed to be fatal to brood, and Dr. Fakhimzadeh stated that it is the OTC itself that can kill the brood, not the sugar. Again, we only used sugar and we didn't do each frame. We'll report our results later.
Methods of mite counting
It's good to have a varroa screen or a slatted bottom board, or at least a sticky-board insert with a mesh cover. Sugar dusting will not help if the mites can crawl onto another bee after they fall. Mites can fall through a varroa screen or screened bottom board any time.
If you slide a fresh sticky board in just before you do your dusting, you can get the most accurate count. There are many methods to count. We demonstrated an "ether roll" test... but also, check out the sugar roll test.
Frequency of dusting
Again, thoughts vary. Remember, you are disturbing the hive... especially if you dust frame by frame. We read 3 consecutive treatments 1 and a half or two weeks apart. You have to use your judgement on your own hive as to how many are too many mites. Seeing only a few over a certain area is not as much of a concerns as seeing very many over the same area.
You could sugar-dust a hive every week, but think of the impact on the productivity of the bees. Maybe you can tolerate a low varroa population and do a sugar roll or an ether roll as often as you want to make the best decision when to dust.
Varroa population, should be monitored ongoing, but seems to peak between June and early September in our area. Some of our members say they will do three dustings about 2 weeks apart before winterizing the hive. Good luck.
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