oxalic acid glycerin strips testing

[tristan]

quick update on some OA/GL testing that i previously mentioned.

most of the testing is more about handling, making and how hard can you push it before something breaks.
this all done with single broods.
i have one hive with Swedish cloth with 1.5 mix. the bees didn't like walking on it to start with, but after a week they seam fine. its placed under the wire excluder so there is bee gap. they walk on it and go up through the excluder just fine.

have one with bamboo cloth. (thx @Dansar). its actually works out to be the right size, holding the right about of mixture, if you fold it in half.
however the bees simply avoid it. they don't walk on it, tho it looks like some chewing on the edges. thats looking like a big fail. again its lying on the top bars under the excluder. it kinda looks wetter.

one hive currently has 6 cardboard strips (the gib packer stuff), so about a double dose. placed from frame 2 to 8. i found that most of the laying had stopped on most frames except frames 1 and 10. however i checked recently and they are all brood again. this hive is not tested for mites, its purely a survival test. a little surprised there's no pile of dead bees.
is the lack of lay a bad thing? on one hand it slows the hives progress, but it also provides a break so that all the mites can be killed. maybe having too much treatment might be a good thing.

i have a couple of hives with mite testing, one with strips and one without. results won't be for another month yet. also its a only a sample of one so @Dave Black don't shoot me just yet.

also noticed almost no residue comes off the strips after a few weeks, which makes it much safer to handle. i find the vertical strips much easier to handle than the flat swedish cloth etc when working the hives.

my suspicions at the moment is that the nz 1.5 mix spreads easily early on providing a knock down effect, but may suffer from very little mix being in the strips. from what i can read online is the 1:1 usa mix takes longer to get spread around. using a lot more mix to get similar results.
so whats best, high early dose for knock down or one that continues for a long time?

 

[Dennis Crowley]

so whats best, high early dose for knock down or one that continues for a long time?

Maybe a high dose to start with and then the lower longer lasting dose for maintenance

 

[yesbut]

Maybe a high dose to start with and then the lower longer lasting dose for maintenance

@ double the handling

 

[Josh]

I think OA will become part of the solution.

I have 4 hives with the Randy Oliver formula Swedish cloths. All hives treated with conventional spring treatments. Highest varroa count prior to OA was 4/300 and lowest zero. That was about 6 weeks after treatment came out.

I run double 3/4 brood boxes.

Immediate impressions… no issues, some chewing. No idea if bees walk on them really (can’t see when the hives closed), but they are dirty and bees are on when I split the boxes. No avoided comb like I saw with the strips previously used. No weird queen laying habits like strips.

One queen failure, but I’m pretty sure that’s a coincidence. They were previously trying to swarm even before strips went in and was behaving very weird.

Mite counts yet to be rechecked, but will keep you posted. If you want.

Very easy to make, store & use.

 

[tristan]

Maybe a high dose to start with and then the lower longer lasting dose for maintenance

that approach i think is best. get enough spread around the hive quite quickly and get a good varroa knockdown. then have enough released to continue to kill over a long time period. but the catch is one material type might release fast at the start but not be able to release enough constantly later on.

@ double the handling

not necessarily so.
i suspect the staples already act like that. the wetter mix gives it high spread ability which should give a quick knock down. despite carboard being slow to release and releases very little mix.

but also you could do a two stage strip. for eg randy oliver tested cotton pads which seam to release a lot of the dry 1:1 mix and have high mite drop very quickly. no reason you can't have two different strips at the same time, one fast release one slow.

 

[tristan]

Mite counts yet to be rechecked, but will keep you posted. If you want.

please do.

 

[tristan]

small update.
the hive i'm doing mite counts on has chewed most of the strips away. probably about 30% left.
that poses a serious problem. the hive won't get any treatment if there is no strips left in it, and the time its been in is border line, especially for a slow release treatment.
i may try a 1:1 mix and hope the extra acid content stops them from removing it.
or change the strips to something else.

no issues with brood at all, pretty much slabs of brood except for where the strips are. main reason for checking was to add boxes.

 

[The Frasers]

A few years ago as noobs we made strips from tree-binding tape as a vehicle for oxalic, and saw a reduction in mite numbers in the two hives we kept back then. Bringing the idea to the Forum got us a less than encouraging reaction, and we were advised to go back to something that actually worked (patent remedies)
We asked then if someone with experience that had been involved in the discussion would care to run a proper trial and disprove the effectiveness of binding-tape, but the that wasn't to be.
Tristan, this might be worth a try as part of your experiment. The remainder of the roll we have measures 50mmx1mm thick, is woven plant fibre, and we hung it like the patent remedies as strips down into the brood, by toothpicks pushed through the top edge. Nothing "grew" under the strips, and they didn't get chewed by the girls either. We generally left them in place for a month in November and again in January, but then, we were noobs! Would you consider giving this a crack?

 

[tristan]

Would you consider giving this a crack?

sure, if i can find the stuff.
if you know of an online source of the stuff please post it.
full trail won't happen until near the end of season. but i hope to get small scale testing before xmas.

 

[James]

Hmm, we been using o/a for a few years now.
After an intual disaster we seem to be on track, using synthetics in the late summer, and o/a in the spring.
As we box the bees up we plonk on a final bluecloth above the brood…. Job done

 

[tristan]

Hmm, we been using o/a for a few years now.
After an intual disaster we seem to be on track, using synthetics in the late summer, and o/a in the spring.
As we box the bees up we plonk on a final bluecloth above the brood…. Job done

are you running double broods?

 

[tristan]

a quick test today showed mite numbers have dropped. which is good, but its to early to tell. a few more weeks before i can give a bit more accurate result (due to brood cycles).
if it does perform ok, it may be suitable for a short term mid season treatment. just to give the mites a wack to keep numbers down and where failure is not going to cause major problems.

 

[The Frasers]

@tristan, this is the packet of tape we bought last. Hopefully not consciously breaking rules by doing this, but one picture -v- lots of words...
We haven't looked on line yet but our roll came from a garden center in Masterton who don't have a web site. It would be reasonable to expect that the stuff isn't that rare though.

Thanks.

 

[The Frasers]

View attachment 1558

@tristan, this is the packet of tape we bought last. Hopefully not consciously breaking rules by doing this, but one picture -v- lots of words...
We haven't looked on line yet but our roll came from a garden center in Masterton who don't have a web site. It would be reasonable to expect that the stuff isn't that rare though.

Thanks.

Update: Mitre10 have this tape. Check your local branch stock list?

 

[tommy dave]

the catch is one material type might release fast at the start but not be able to release enough constantly later on.

that screams an idea of strips made of two materials - the lower section fast release, upper lower, dunno how that would be practical though

not sure if that's what you were getting at with the two materials idea, i read it as using two different types of strips at the same time, so my idea might be what you were already getting at, but if not, anyway, if not i typed it just in case it's useful

 

[tristan]

just a small update.
things are delayed a bit with me being off sick and now xmas.

however i have just put a Swedish sponge in one of the home hives (double brood).
i made up some 1:1 mix, which is a lot different from the 1.5:1 mix used with the cardboard strips. this 1:1 mix, once cooled down, ends up more like cake icing or finely crushed ice instead of gelatin. i made a bit of a mistake in that it really needs to be dried while its still hot. i left it overnight and i had to scrape/wipe all the excess off the strips. however the surface does end up being rather dry and the bees walked over them with no issues (i tried a bee on the 1:1 raw mix and it walked over it without issue). with the 1.5:1 carboard and Swedish sponge, the bees did not like walking on it at all. it seamed to be very hot on their feet at the start.

the other interesting thing is the Swedish sponge soaked up 119g of the 1.5:1 mix and with the 1:1 mix a whopping 210g. consider Randy Oliver talks about 50g a sponge. i hope that it translates into a longer treatment time.

 

[tristan]

small correction, it looks like Randy Oliver gets around 110g per swedish sponge with 1:1 mix.
no doubt some variations between brands. i also see one that is a thinner version, which may be more applicable for using between frames.

 

[tristan]

small update:
checked home hive that has the swedish sponge. weighed the sponge and its certainly lost weight. its also got dead mites all over it. however the bees have proplized it a fair bit as its really a bit thick for the bee space on these boxes. the problem is that it throws out any weight measurements. so all i can say is its lighter.

also what i can't test for is what the remaining mix is. really need to test the remaining mixture at the end of treatment to see how much oxalic acid is still remaining so we can get an idea of how much has actually been distributed into the hive.
it may be that the strips soak up moisture (as glycerin soaks up moisture) which increases weight, so more oxalic may be coming out than is indicated by weighing the pad.

otherwise things are somewhat delayed at the moment, but got some gear on order so hopefully back to it soon.

 

[Josh]

small update:
checked home hive that has the swedish sponge. weighed the sponge and its certainly lost weight. its also got dead mites all over it. however the bees have proplized it a fair bit as its really a bit thick for the bee space on these boxes. the problem is that it throws out any weight measurements. so all i can say is its lighter.

also what i can't test for is what the remaining mix is. really need to test the remaining mixture at the end of treatment to see how much oxalic acid is still remaining so we can get an idea of how much has actually been distributed into the hive.
it may be that the strips soak up moisture (as glycerin soaks up moisture) which increases weight, so more oxalic may be coming out than is indicated by weighing the pad.

otherwise things are somewhat delayed at the moment, but got some gear on order so hopefully back to it soon.

My pads are nibbled on 3, eaten 30-40% on 1. Because of the way the way water interacts with glycerine and OA, and bees eating the sponge, weight would be a poor surrogate for dispensing.

Randy Oliver’s work would suggest there is a dose/hive of OA to be effective, and a surface area requirement to make delivery effective.

 

[tristan]

My pads are nibbled on 3, eaten 30-40% on 1. Because of the way the way water interacts with glycerine and OA, and bees eating the sponge, weight would be a poor surrogate for dispensing.

Randy Oliver’s work would suggest there is a dose/hive of OA to be effective, and a surface area requirement to make delivery effective.

interesting they are nibbling on them. i will have a closer look next inspection.

the pads are well above Randy's minimum dose, tho the surface area comes under question if frames are sitting on it or its getting covered in debris.
one of the many many questions is how much does the pads hold permanently, ie how much will never come out. is there any point to having 200g a pad vers 100g?
the strips seam to work ok even tho they hold a very very small amount. even if you double/triple treat (due to strips being removed by the bees) the amount is very little.
we could use a thinner pad which holds less but fits in the bee space better. or a thicker pad that holds a lot that might last 3-4 months, which might be good against mite drift.
lots of paths to go down.