Formic Pro treatment & wet weather

Hi all

After a recent mite I counted 6 mites in both my hives last week and have bought some formic pro. But I didn’t get a chance to put it in and now it’s forecast to rain for another 1.5 weeks. It’s mid Autumn in Sydney (I am based in Berowra). It is around 12⁰- 20⁰C.

If there is a couple of hours break in the rain during the day should I put the formic pro in? Does the rain affect the efficacy of the product? Or is it because bees are less likely to fly around when it rains? I am seeing activity when there’s a break in the rain (they seem to be buzzing in and out even when there’s light drizzle!)

I am weighing up impact of colder weather after it stops raining (I think it’ll be 1-2 degrees cooler).

Any advice / opinions is much appreciated! Thanks in advance.


Well done on doing a good mite count! I would put it in whenever you get a chance. Cool weather isn’t a problem with formic acid, it is hot weather that really causes problems. :blush:

There is quite a good overview here:

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Thanks @Dawn_SD! This is super useful! I think we only have Formic Pro, Bayvarol (Flumethrin) & Apitraz. I wonder why we can’t get Oxalic acid or the other essential oils? Perhaps they will be introduced over time.

Do you recommend rotating between synthetic & “natural” control methods? Or can you rotate within natural ones until you are unable to control mite populations?

Also I didn’t realise this is recommended for Formic Acid: “Use acid resistant gloves and protective clothing. Although no longer required;
Caution, it is recommended to use a respirator and eye goggles when handling this
material”…I was just going to wear my Covid N95 mask - would that be ok? I have eye goggles but no respirator. I thought that was one of the benefits of formic acid over oxalic that it’s “ok” to breathe in? :thinking:

I use mainly oxalic acid, but if mite counts are high in the autumn, I use Apivar strips.

I think this is CYA (Cover Your Arse) policy from the manufacturers, in order to avoid lawsuits. If you are careful, and try to stand upwind of the product, you don’t need excessive protective equipment

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Thanks very much! I hope I haven’t left it too late! I’ll report back in a couple of months !

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You should be fine, but I look forward to your update. Thinking good thoughts and good karma for you! :blush:

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Dawn’s advice is solid as usual.
Be prepared to see some dead brood and bees. Don’t panic, there may be some that already suffered multiple injury from mites and they tend to succumb to the treatment.

Regarding oxalic acid, there are two products currently undergoing APMVA registration with no indication of their progress. We wait patiently.

Amateur Beekeepers Australia is lobbying the federal government to adopt New Zealand’s “own use exemption “ approach. This would allow beekeepers to experiment and treat their own hives with their own recipes. With registered products, we are legally required to follow the label even when research shows that a different dose is more efficacious. The “own use exemption “ would decriminalise the process of fine tuning treatment recipes.

It will be a slow process to change legislation, but with every beekeeper in the country raising the topic with their federal mp, it could happen sooner than later.



Thanks @aussiemike @Dawn_SD. Very interesting to hear the context on different treatments - there’s always politics & red tape.

I managed to squeeze in a treatment application in between my lunch break today whilst the rain also paused. I decided to wear protection eye goggles + N95 mask that I had lying around. My “anti-fog” goggles fogged up pretty badly so it made it difficult to put everything back. Plus I am not super strong so had a few goes at putting the super back on top of the queen excluder! (QE kept moving). My husband normally helps me with the boxes which makes it easier to align them!

Amazingly I only got stung once - very sorry bees for my heavy handedness!

Checked back after a few hours, yes there are some dead bees at the front. I can see condensation from the windows so I assume the vapour is working. Oh poor bees! I hope they survive.

It is now 5pm, sun will set soon. I may have to attempt the next box on the weekend or next Tuesday when the weather is supposed to clear up again (minus eye goggles!)

PS I also thought it was 1 strip per pack - there’s actually 2 strips per pack so I only used 1 pack for 1 hive. So its actually not as expensive as I originally thought! So there’s something positive from today :joy:


Good work, Liyi. Beekeeping is not for sissies. I just climbed back down a yew tree on my property after failing to rig a box close enough to capture the swarm that settled about 15 ft up - I am now pretty worn out!

About oxalic acid, I wonder if your hardware stores sell it? That’s where I get mine, not from a beekeeping supplier. It’s sold as wood bleach and comes in powdered form in a tub.


That’s hectic @Eva ! :muscle:t2::muscle:t2::muscle:t2: I’m glad you’re relatively unscathed! Thanks for the info, even if they don’t stock it, Amazon will ship it! :joy: How do you apply it?
My 4 packs of formic pro should last me year.


Thanks, me too :sweat_smile: I’m glad none of my neighbors saw me up there (I think)…

OA can be applied as a liquid mixed with sugar water and dribbled directly onto the bees between each frame. It is also vaporized using heated tools that are kind of pricey. Another method is to dissolve it in glycerine and soak flat Swedish dishcloth sponges in it, let these dry and place them on the top bars. The bees then chew them up to remove them and thereby transfer the OA throughout the colony.

I tried the OA vape method for a few years until I learned about the sponges. Vaping is very effective when well-timed according to mite counts. But I found it cumbersome and a little scary, considering the high heat and caustic vapor. You still have to take precautions when using it in a dribble or sponge method, of course, because it is strong acid and will burn skin and eyes. It is just simpler for me to make a batch of the sponges each season and place them in during my first round of inspections. Then, as @Dawn_SD said, monitor in case a “booster” of Apivar is needed.

Randy Oliver came up with the idea to try delivering OA using thick paper towels or sponges, here’s his article with more info:


Wow - so much to learn! Didn’t know OA is in spinach! Sponge method def sounds easier than vaporiser - thanks for sharing!

So I managed to treat the second hive today when the rain paused. It has just started to rain again as soon as I got back inside. It was SO much easier without the foggy goggles and actually being able to see this time! :joy: Managed to put the strips in the right way round too. (Hopefully the treatment will be ok for the first hive even though they were the wrong way round). This second hive feels stronger than the first - it had more brood & capped honey in the brood box. :muscle:t2: This hive was actually from a swarm that I caught back in spring so it has my original old queen.

Upon outside inspection of the first hive there were more dead bees outside maybe 50-80? No bees in the super - I am guessing they’re busy trying to get rid of the formic acid pads from the brood?:thinking:

So now I just leave them for 14 days before I inspect and test again?

It is in quite a few plants, and even in their nectar, if they are nectar-producing varieties. Some of the highest levels are found in rhubarb. It doesn’t work to plant these varieties around the hive though, you have get the OA into the hive. :blush:

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That makes sense, can’t imagine mites wanting to chew on a rhubarb! :joy:

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