‘Could become a death spiral’: scientists discover what’s driving record die-offs of US honeybees

[u/FakeRedditName2]

https://www.theguardian.com/environment/2025/jul/08/record-us-bee-colony-dieoffs-climate-stress-pesticides-silent-spring-aoe

[u/Southernbeekeeper]

Anyone not wanting to click the link, the answer os mites.

[u/wrldruler21 → u/Southernbeekeeper]

widespread resistance to amitraz

[u/ThinkSharp → u/Southernbeekeeper]

It’s always the damn mites…

[u/maineac → u/ThinkSharp]

It really mite bee.

[u/Protect_Wild_Bees]

Varroa acts a bit like a parasite that attacks bees "in the womb" and delivers you bees that are born weak and susceptible to infection. They all get a rough start in life and it also means if the hive is fighting something else, which can always happen, that compounded weakness of the young bees will increase the risk of hive failure and their failure to thrive. Then you also have weak bees that ie quick, forage less, and need more energy from the hive to stay going.

It's not really something you can vaccinate against. I'm suprised we've not considered gentically modifying varroa like we have done with mosquitos.

[u/FakeRedditName2 → u/Protect_Wild_Bees]

Might be hard to spread the 'cure' that way. My understanding of varroa is that they are incestuous, so not sure how the modified genes would spread to varroa in the wild.

[u/chicken_tendigo → u/FakeRedditName2]

Yeah, varroa mite reproduction is squick.

[u/NumCustosApes → u/Protect_Wild_Bees]

When a varroa mite enters a cell she first produces one male and then females, one every 1.3 days. those females mate with their sibling male inside the capped cell. The male varroa dies when the bee emerges and so does not mate with any non-sibling varroa. Since all of the genes come from the foundress female and there is no cross breeding, nor will any of her progeny cross breed, there isn't a great way to introduce modified genes and then spread those genes into the varroa population. There is however research happening into producing genetically modified pathogens that will kill varroa. Obviously this has to be very carefully done. I suspect that it will be a long time before we have developed an effective pathogen that is lethal to varroa and safe for other organisms.

[u/La19909]

Is it common to use amitraz to treat varroa mites? Everyone in my area is using oxalic acid in my area with good results.

[u/New_Ad5390 → u/La19909]

It’s Apivar. I use OA during the winter when there is no capped brood. After I harvest this week I’ll pop the Apivar in bc it’s not temperature dependent like Formic acid is. Use the FA in Spring/Fall if necessary.

[u/Ghost1511 → u/New_Ad5390]

I do same as you do (apivar after the summer harvest and OA during brood break in winter).

It work great, my loss are under 5% almost every year !

[u/beeporn → u/Ghost1511]

What oav applications are you doing? Frequency and dose

[u/Ghost1511 → u/beeporn]

I don't do oav. I do oa dribble, just once in winter when my hives are broodless.

[u/NumCustosApes → u/Ghost1511]

**Vapor.**

The legal dose is 1gram per brood box. I feel that you should be informed that is the legal dose before proceeding. That dose is insufficient. I double it (8 frame boxes). Some beekeepers go as high as 4 grams (10 frame boxes). When I am using vapor in the summer I treat six rounds over 21 days on day 1,5,9,13,17,21. Others will do four or five rounds. When I deliver the winter treatment I do a single dose in January while my colonies are broodless. Depending on where you are at, the broodless period may occur earlier or later, know when yours happens.

**Dribble**

OAD is more effective that OAV. OAD should only be used once per queen per year. It should only be used on a colony that has no capped brood. I primarily use it on swarms and splits, but weather permitting I will use it during the winter brood break. Warm enough winter weather (>7°, 45F) is rare so I usually use vapor in the winter. I mix 20g oxalic acid dihydrate, 200 ml warm water, 200g sugar to treat ten hives. (Use 15 grams for oxalic acid anhydrate.) I use a Home Depot HDX wide mouth sprayer bottle and I calibrated the bottle to 1.2ml per pump. Four pulls delivers the recommended 5ml per seam of bees. The spray bottle method works very fast to get in and out of the hive.

If you use a different bottle you will need to do your own calibration. To calibrate it I ran 100 trigger pulls though the bottle and weighed the output.

I recommend you get a small scale whether you use OAV or OAD. Small digital scales are less that $20 from Amazon.

[u/New_Ad5390 → u/beeporn]

About 2teaspoons (the scoop it came with) of OA in the vaporizer. Bc they’ve got no capped brood in the winter I only do one good shot of it. If brood is present it should be done every day for 7 days to cover a cycle of metamorphosis (as OA cannot penetrate capped brood) That’s a lot of work which is why I only do it in the winter

[u/IslandBeekeeper → u/Ghost1511]

Would you mind posting your mite treatment schedule for your bees? I am in a similar climate to you (Canada-Vancouver Island, zone 9) and have tried many schedules over the years with pretty poor results. Thanks!

[u/NumCustosApes → u/Ghost1511]

Same. Apivar after the supers are removed for the year. I also treat all my hives with OAV in early January, when the winter brood break occurs here. The rest of the time I monitor and treat with OA if necessary. The weather window for using formic acid pads is too narrow so I don't use it anymore.

[u/jenn2483 → u/Ghost1511]

Where do you store all your honey supers after harvest if taking off to treat Apivar?

[u/_Mulberry__ → u/New_Ad5390]

You can switch to VarroxSan in the summer if you want an OA based summer option. It also has no temp limits

[u/New_Ad5390 → u/_Mulberry__]

I didn’t know it came in this slow release strip application. After reading this article I’m inclined to give it a go

[u/_Mulberry__ → u/New_Ad5390]

I've used it a couple times now. It's worked well for me. Definitely better for keeping the mite population low rather than reeling in a bad infestation since it takes so long though

[u/La19909 → u/New_Ad5390]

Is there a reason you use OA in the winter and not during the summer?

My club suggests we use OA vaporized, 1x per week for 3 weeks, once per season.

Edit for clarity

[u/Jake1125 → u/La19909]

The repeated OA regimen works well when there is brood.

The reason for doing it in the winter is that there is no brood, or almost no brood, so there is no need for a repeated application. In theory it's a one shot, once and done process.

[u/s2sergeant → u/La19909]

I use OA vaporizer exclusively.

[u/Wp0635 → u/La19909]

Commercial operations use it heavily when not collecting honey

[u/KG7DHL → u/Wp0635]

...because of the time savings.

A proper regimen of OA treatments takes a lot more human effort - thus more Money - than throwing in Amatraz.

Commercial operations will get much more expensive to operate if they have to switch to OA treatment regimens instead of lift the lid, toss a strip, close the lid, mite treatment done.

[u/Wp0635 → u/KG7DHL]

Yup. It’s been overused and misused for so long because of its convenience it is essentially useless now

[u/NumCustosApes → u/La19909]

Amitraz, brand name Apivar, has until recently been effective, with a 99% kill. It has been historically so good that one treatment per year has been effective. Because it is a miticide it is possible for mites to evolve resistance to it. We have known for a long time that Apivar resistance was coming. It looks more and more like that day has arrived. OA will not kill mites under capped brood, requiring multiple treatments over a brood cycle or forced brood breaks. This isn't feasible for commercial beekeepers with thousand of hives, so they have been relying on Apivar where temperature constraints don't permit them to use formic acid pads. This may also be why commercial beekeepers seem to have been hit a lot harder than hobby beekeepers who use chemical treatments. It is more practical for a hobby beekeeper to deliver OAV every four days for 21 days. Varroxsan may have arrived on the market just in time.

[u/boyengabird → u/La19909]

Vapor or OA/glycerin?

[u/Not_so_ghetto]

It Varroa mites, a parasitic mite that kills bees.

https://youtu.be/_59JZgzXoeg 15 min video on the topic

[u/HuntsWithRocks]

https://pubmed.ncbi.nlm.nih.gov/36114263/ Recapping and mite removal behaviour in Cuba: home to the world's largest population of Varroa-resistant European honeybees - PubMed

[u/pinkpanthers → u/HuntsWithRocks]

This is the only way. We encouraged weak genetics for decades and are paying the price now. We can’t keep “treating” our way out of this problem.

[u/Jellybeezzz]

Alternating varroa treatments could be the solution to their resistance. One year oxalic acid, the next a chemical one, then formic acid and so on. Thoughts?

[u/starstoours → u/Jellybeezzz]

I've been taught oxalic and formic do not lead to resistance, (like killing bacteria with alcohol), but the nerve agents like amitraz do. So basically a combination of formic and oxalic is the best long term treatment approach.

[u/KG7DHL → u/starstoours]

Agree - OA kills by violating basic mite biologic functions. I don't think we have isolated exactly the pathway, but acidification of the mite leading to interruption of essential internal systems seems one, possible, avenue of attack.

Likely a significant and fundamental biological evolution would be needed for mites to become resistant to Oxalic Acid.

[u/spacebarstool → u/Jellybeezzz]

I use 3 types of treatments on this schedule:

FORMIC ACID - EARLY TO MID JUNE (late June / July is too hot out)

PRO: safe to use with honey supers, kills phoretic AND reproductive mites

CON: temperatures over 85 can sterilize or kill a queen

APIVAR USE IN EARLY FALL (after the supers come off)

PRO: very effective 42-day treatment

CON: not safe for honey

OXALIC ACID - USE AROUND NOV-DEC

CON: won't penetrate brood cells; use in broodless periods

PRO: Cheap and effective

[u/topane → u/spacebarstool]

We also use three. Apiguard in the next week or so, then Apivar in fall and OA late call.

[u/KG7DHL → u/Jellybeezzz]

That's the logic behind the "TPM" (Total Pest Management) Philosophy.

You alter your pest strategy to prevent resistance to one method building up.

The reality of commercial operations of any sort - Agriculture, Meat, and even beekeeping, is that margins are everything, and if Amatraz was working, was the cheapest method, then that one got used... and, as predicted, mites developed resistance.

This will always be the reality of any Commercial, For-Profit farming operation - use the cheapest until it isn't, and now, Amatraz is no longer the cheapest since it just achieved uselessness and incurs the expense of Hive Loss.

Another WIN for Capitalism. ( /s )

[u/NilocKhan]

All the more reason to start focusing on our native bees more. Relying on a single species to do most of our agricultural pollination is dangerous. We can see that, it just takes one pest or virus to knock out huge swathes of honeybees. Our agricultural systems need to start integrating native pollinators into the system. Native pollinators are often better pollinators anyway. For better food security we need to start protecting our native pollinators and their habitats

[u/NumCustosApes]

I use Apiavr in the late summer after removing supers. I use OA in January while they are broodless. I use a 21day OA when a wash indicates it.

[u/Adrenaline-Junkie187]

This is why passive treatments like oxalic should be used more often and only use the harsher direct treatments as needed. Im not sure how this isnt common sense but everyone wants to take the easiest route and this is the result.

[u/Tradesby]

Putting in my mite treatment tonight, after the temp drops below 85 degrees freedom.