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Are there vaporized Oxalic acid failures?

5K views 27 replies 15 participants last post by  RudyT 
#1 ·
I treated my two hives in August 5 treatments, 4 days apart in mid August. Then on December 23, 2018 I treated again. I DID NOT do an alcohol wash after the treatment in August, and did not open the hives in December. I chose that day because the temperature rose to about 50 degrees. I just inspected the hives and there is still a lot of honey, several dead bees, and very few live bees, no brood. I did not do an alcohol wash thinking the OA would be effective. are there any reports of OA failure? I burned 2 grams of OA over 3 minutes and closed up the hives for 10 minutes. there was vapor coming out at the top of the hives. I thought I was good>
 
#5 ·
I think there is too long a gap after the August treatment; time enough for reinfestation from other hives and survivors of your own treatments. I found that I had to continue for several more rounds ( 4 vaporizations to a round) before the mite levels stayed low. With your later autumn you had an even longer period for mite levels to rebound to levels bad for the production of long living wintering bees.

Waiting too late to commence treatment is fatal and I think early treatment without followup can also lose the battle to the mites.
 
#14 ·
I think there is too long a gap after the August treatment; time enough for reinfestation from other hives and survivors of your own treatments..
I'll copy a real example of what re infestation from other hives can do to your hives, and this lady counted every mite on the sticky boards and I went a made sure she was only counting the mites. I do have to check with her and see if they are still alive. we had done an alcohol wash end of july early aug. with one mite in the wash.

Formic Pro treatments
8/16, 1 strip each hive
8/30, 1 strip each hive (too hot to apply before this date)
9/23 - 9/28 sticky boards
Pink hive = 188, avg 37.6 per 24 hrs
Blue hive = 133, avg 26 per 24 hrs
White hive = 86, avg 17.2 per 24 hrs

10/14 - 10/18 sticky boards on for 75 hrs
Pink = 524, avg 167.68 per 24 hrs
Blue = 320, avg 102 per 24 hrs
White = 17, avg 5 per 24 hrs

10/19 ProVap110, 1 g per box, sticky boards inserted
10/22 count per 3 days
Pink = 2,439, avg 813 per 24 hrs
Blue = 1,269, avg 423 per 24 hrs
White = 844, avg 281 per 24 hrs

10/22 ProVap, no sticky boards

10/26 ProVap, sticky boards inserted
10/29, 74 hour count
Pink = 1,082, avg 351 per 24 hrs
Blue = 1,499, avg 486 per 24 hrs
White = 44, avg 14 per 24 hrs

10/30 ProVap, sticky boards inserted
11/2, 3 day count
Pink = 1128, avg 376 per 24 hrs
Blue = 830, avg 277 per 24 hrs
White = 13, avg 4 per 24 hrs

11/2 ProVap, sticky boards inserted
11/5, 3 day count
Pink = 516, avg 172 per 24 hrs
Blue = 455, avg 152 per 24 hrs
White = no sticky board inserted

1/6, 24 hour count with no treatment
Pink = 79
Blue = 36

11/7 ProVap, sticky boards inserted
11/10, 3 day count
Pink = 572, avg 191 per 24 hrs
Blue = 181, avg 60 per 24 hrs
White = no sticky board inserted
she did a later treatment but I can't find the numbers, we then sent a sample of her bees to be checked, no mites, no nosema, low virus's, and good weight of the bees.
 
#6 ·
That was going to be my next question: if the mite numbers were high in August and didn't come down, what would you treat with? That's another mistake I made I used MAQS and it go hotter than predicted and I killed the queens. Often doesn't get cool enough here in August to use MAQS. What do you use?
 
#8 ·
Frank's answer is spot on to your situation. August to start, then again in September, and again in October. Single dose at Thanksgiving and Christmas. Just had the State sample my hives for mites. Checked 25% of the hives with an alcohol wash. 0 mites. Healthy bees. OAV works if used correctly.
 
#9 ·
I agree with JWP. I generally do weekly treatments from the second week in August, (that is my last honey harvest) through October.

I do a treatment just before adding supers the first of May. I usually harvest honey the end of June and do one treatment while the supers are off. I have never used anything other than OAV.
 
#11 · (Edited)
Eric, not sure who you are asking. I brought all 16 of my hives through winter, only to lose one to starvation this week. I will be at 20 production hives and 20 nucs for sale by June. I use a ProVap110 so it does not take long.
 
#12 ·
Every time you put some oav crystals on a mite they die of that I am 100% sure, where we might fail is getting those crystals on all of the mites. I am not sure an OAV treatment will get the mites that are under the bees scales feeding on the bees fat belly so getting all the mites is always going to be a problem and as far as I am concerned can only be taken care of with many treatments. This may be a problem with many beekeepers using the old varrox type of pan system but with the new type of vaporizer treatment can be done very quickly and easily. As I have yet to see any negative effect of these treatments on queens bees and brood there is no reason that hives could be treated once a week throughout the year, I do mange to keep my 40 odd colonies going from year to year with losses below 10% overwinter with about 12 treatments per colony per year. Lets face it if you want OAV to be as effective as Apivar just treat your hives every day for 42 days and I am sure you will get the same results.
 
#13 ·
To also take another point of view, Yes, there are OAV failures. There are also failures with MAQS and Apivar, and every other treatment available. Usually, it is user error with any treatment. I also feel re-infestation from collapsing hives is a real issue in some areas. If your hive drops hundreds of mites when you vaporize, it clearly is working. What I find is most important is to know the pattern of mite buildup in your area. To figure out the pattern, you need to do mite testing several times in the summer and spring. In Kentucky, your pattern is way off of mine here in the Seattle area. I can get away with 3 or 4 treatments of OAV in early August and 1 in December. There are not a lot of hives in my area. I am suburban or urban for miles in every direction and there are few beekeepers. Your area may have lots of beekeepers or feral hives in the woods. A simple mite test to figure out the pattern is to vaporize on the first day of each month. Check your mite drop 3 days later with the sticky board you will have put in right after vaporizing. You might be surprised at the results. After the second year, you will have pretty good data to work with.
 
#16 ·
luckily the nearby hives that were collapsing ran out of bees and mites she hopes. now just to expand on it, the lady had 4 hives, the neighbor had 5 but couldn't determine how many were actually alive or had been alive. through it all she only found a few bees with DW, so we figure since she was treating every 3 or 4 days she was killing the mites as they were coming in. The other thing that was interest two of the hives mite count really didn't go up much the other two hives were doing all the robbing.
 
#18 ·
I check and count mites before August to determine which of my hives control mites best, those I split from if I do splits but from August on I just treat. I want healthy winter bees and I expect robbing by my bees. If you discover high mite counts late in the season it is too late to treat for the winter bees in Michigan (opinion).
 
#20 ·
OA is no different to any other miticides as it kills by contact, as does amitraz or most other chemical concoctions. The difference is that the OA remains in the colony for about 3 days whereas the other stuff stays in the colony for 42 days so go ahead and treat your colony with OA every 3 days for 42 days and I believe you will have the same efficacy as amitraz or similar miticides. Now it is quite possible to get away with much fewer OA treatments but really one must compare apples to apples. A few years back it was quite a hassle to treat with OAV but not anymore and the price is good and there is not much chance of the critters becoming resistant to OAV but we cannot say the same for amitraz.
 
#21 ·
I may be wrong but I assumed that the OP is a hobbist like myself with only a few hives to manage. With only a limited number of colonies to treat I do not find OAV unmanageable and for the five years I have used it exclusively I do not believe I have lost any colonies to mites. One size does not fit all and we all have different objectives.

I bother because I have determined that OAV suits my needs. My post was intended to address the OPs concern not to debate.
 
#22 ·
There are reports of people getting acceptable mite control with 7 day interval treatments but my feeling is that 4 or 5 day gives better results. "Works for me" advise is not the best decision criteria though. I am not in an area with a lot of indrift from other bees and have rather low levels to start with.

I suggest if you are starting out with OAV to have screened sticky boards under some of your hives and monitor mite drop for several weeks before you start OA then again regularly to see how effective the treatments are. Keep on doing your series of treatments until the mites drop to, and stay, at the level you think is safe. Like johno I dont count how many times. I have not seen any failures or mortality.

If you start too late in the season or have mite rebound in long autumn conditions, you will have treatment failures no matter what method you use.
 
#23 ·
I want to thank everybody for their replies. I am resolved to 1) do frequent alcohol washes, 2) use a longer acting fall, (August, etc,) treatment and/or treat more repeatedly with OA, and 3) attend the local beekeeping meetings more. I have read where other folks want to quit but I am determined to keep my bees alive. I know if others can do it I can too. Sure not as easy as it was when I was young. Of course that's true of a lot of things. Thanks all
 
#25 ·
There are some great comments in this thread so I have little to offer but emphasis. Bees that die in the winter actually began in August for most of the USA. Northernmost areas experience this more than southern areas. The reason is fatbody = overall health. August bees have the least fatbody. Thin, lean, foraging / defending bees. This is when they have the least fatbody to spare but when mites peak in the environment and in hives. Mite management is an annual event. It is proactive not reactive. IPM is often taken to be reactive which is a failed view. Beginning at month 1, Mite counts should be the lowest and increase relative to brood up to the flow. Expansion numbers are outbredding mites leading to flow. You want low mite numbers. Post flow, bee production slows. Mites peak in August - ish depending on national geography. It’s imperative if your going to treat at all, that this is considered your most important treatment. A clean up treatment should follow in the fall followed by a clean up as flow starts in spring. The tools in our fight against mites are many and often not understood to the extent they should be. I’m of the opinion that all beekeepers should become experts of each and treatment available. Some you may know little about but you should continue to study those until you feel you’ve mastered them. They each have their pros and cons. From a chemical treatment perspective, the Honey Bee Health Coalition offers a great informative chart of these chemical methods and good details. This should be a great start. It’s free. From a non-Chemical treatment perspective, learning is a little more challenging. This is not a money making category but offers valuable tools. Tools that EVERYONE should be keenly knowledgeable in. OTS and forced brood breaks for example. Priceless. Thermal Treatment using Mighty Mite, priceless - kills mites under capped brood every time. This shines brightest in August when mites peak. Too hot for MAQS for a 7 day string, provides the quickest / most complete Mite kill. Colony strength is maintained (contrary to forced breaks and intoxicating bees chemically stunting them) and no need for repetitive treatments hoping to get enough reduction vaping. Dribble is a great tool this month but must be repetitive due to the reproductive machine under that caps. Highest risk for queens so you’d better have spares banked.

Mite management must be viewed on a 12 month calendar. You must sample to know numbers. You must be lowest in spring. You need to have most when bee production recedes post flow and knock them out at peak. Clean up in fall and you will have healthy, vigorous thriving but most importantly - surviving bees.

If you research Mighty Mite on Facebook or the internet, you will find year over year a group of people who understand mites and the most who have zero losses or the lowest losses of us all for this reason.

Learn mites cycles on an annual basis. Learn bees cycles on an annual basis. Learn all you can about the chemical and non-chemical approaches. Be proactive and not reactive. Goals should not be 3:100 each of 12 months but by viewing August (or your locals Mite peak) as your #1 most important mite treatment regardless of method used, fall #2 and spring as #3. You will be able to provide any additional treatments that may be needed and master this mite management thing forever and stop loosing colonies.

None of us will ever master bees. They are too smart for us to master. Mites are dumb. We can master them. Best of luck to you. For all if you Hobby keepers and sideline keepers, cut and paste this in your notes and make it your homework learning assignment. Master the mites and enjoy your bees. Worry less about all the rest. Healthy Bees thrive. Sickly bees die. Beekeeping should be fun.

The commercial guys know this all. They have their calendars mapped, what will be done when, how, by who, where, intervals and methods.

Queen breeders know all of this or they would not be successful at what they do.

Master the mites - enjoy the bee.
 
#26 ·
Yes, many batteries are too weak to generate enough heat with the first 3 min use of the pan vaporizer. I have to do 2 clicks with my small battery. A car battery works great, but is heavy and expensive. :( I look for no residue left from the 2g in the pan of the vaporizer. Any residue left means I need to do another click.

I lost a hive couple years ago with low mite counts in August - 6/300 or 2/300 or something pretty low like that - due to mites. There were so many mites in that hive when I realized in Jan that they were dead, there was one on the dead Queen's back...

But those mites did not come from my hive. I can say that with confidence because I checked for mite frass. It is tiny white grains on the roof of the cell, only deposited when a female mite successfully reproduces. There was almost none in the brood comb - very hard to find. But mites were easy to find. They littered the solid bottom. They were all over the dead bees I did an alcohol wash on.

This hive went robbing on Nov 1, which I happened to observe. There was no forage, but they came back from somewhere with abdomens bulging. 2 months later, dead. Those winter bees were fine, until mites arrived and sucked them dry. This is a new take on how hives die due to mites. You can google "mite frass" and find pics, and check your deadouts for it. If you have lots of mites, and no mite frass, then your mites were imported.

Now I find nearby beekeepers and offer them free OAV treatment...and I treat with OAV in early Sept to get a baseline of mite levels, and then about every 2-3 weeks, after a fly day. If the OAV is working, it is killing 90%+ of the mites in a broodless hive. So, 300 mites, then 30, then 3...If you keep getting constant mite drops post OAV, either your hive wasn't broodless, or your bees were importing mites.
 
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