Contents
Formic Vapors and their distribution. 1
Experiments on queen loss because of formic. 6
Experiment #2: Are you able to take away, after which reintroduce the queen?. 7
Experiment #3: Is it the formic or the bees that kill the queen?. 13
Experimenting with Formic Acid
Randy Oliver
ScientificBeekeeping.com
First Revealed in ABJ March 2024
Formic acid is the trickiest miticide to make use of in scorching climate, so I proceed to experiment with more than a few utility learn how to fortify its efficacy, and to higher perceive why it once in a while reasons queen losses.
Closing summer season I ran a number of small “fast and grimy” initial experiments with formic acid; on this article I’ll proportion 3 of them.
Formic Vapors and their Distribution
Formic pad fumes, relying at the focus of the acid, are denser than air (Desk 1) and can thus generally tend to settle in a hive until the bees actively fan them away.
Desk 1 Realize that the extra formic acid is diluted with water, the fewer dense is the mix in their aggregate of vapors as they evaporate (they evaporate in combination at about the similar price).
Nowadays, formic is normally carried out above the brood nest, underneath the belief that its fumes will generally tend to sink down around the brood. However again within the day, Canadian beekeeper Jean-Pierre Chapleau promoted making use of formic at the backside board. This were given me questioning whether or not I may slip a unmarried Formic Professional strip into the decrease front, then seal that front and pressure the bees to make use of a brief most sensible front. My reasoning was once that the formic fumes would generally tend to pool close to the ground of the hive, and slowly diffuse upwards into the brood space, the place the bees can be pressured to fan in recent air from above. That may lead to higher distribution of the formic fumes during the hive.
Experiment #1: Making use of Formic Professional at the backside board, with a brief most sensible front.
So on a scorching day in July I attempted it on a double-deep hive having a beginning mite wash rely of 34. The colony took the remedy smartly, with few useless bees in proof the following day, and a mite rely after 24 hours of 0! Excitedly, I arrange a number of extra hives the similar manner, however discovered that the good relief in mites within the first check was once an anomaly — I’d want a more potent dose.
So I made up transient hive covers with ¾” x 3” openings, plus wedges to seal the decrease entrances. I took beginning mite wash counts from 13 hives in more than a few prerequisites (most commonly deficient — since I didn’t need to sacrifice any “excellent” colonies), and changed every hive quilt with a ventilated lid. I then shoved a unmarried Formic Professional strip into the doorway, and sealed the doorway with a wedge.
The formic vapors had been thus “trapped” within the hive, and the bees had to learn how to use the highest front for get entry to and air flow. The effects had been unexpected (Figures 1-3).
Fig. 1 There have been large colony-to-colony variations in reaction around the board — some bearded up, others omitted the fumes! I took this picture a few hours after making use of two strips of Formic Professional at the backside forums.
Fig. 2 The next day to come, in two hives there have been kills of 800 and 1000 bees. In others, there have been no useless bees in any respect! Pass determine …
Fig. 3 In some there was once kill of open and sealed brood; in others no obvious impact at the older larvae or pupae.
Effects
I’ll help you attempt to make sense of the effects your self (Desk 2):
Desk 2 (QR=queenright; QL=queen misplaced)
- Massive colony-to-colony variability in reaction — some colonies tolerated the remedy, some didn’t!
- Obviously unacceptable grownup bee kills in two hives.
- Excellent reasonable mite relief, however wildly inconsistent (examine hives 8 and 9).
- Strangely little queen loss.
We didn’t observe up on those colonies, however took place to accomplish mite washes on a few of them a few month later (when prepping for some other experiment). We had been shocked by means of the quantity appearing mite counts of 0 at the moment.
I adopted up with some other small experiment — permitting the bees a few days to get used to the highest front sooner than remedy — and plan to experiment extra with the process.
Experiments on Queen Loss Because of Formic
Beekeepers ceaselessly bitch that utility of formic acid in scorching climate might outcome within the loss of a few queens — particularly if they’re outdated or failing (the queens, no longer the beekeepers). However in our operation, we use that remark to our benefit. Once we nuc up our colonies after almond pollination, we put the best-performing queens again into nucs for a moment season. By means of overdue August, they it appears start to run out of sperm, and their colonies naturally begin to rear supersedure replacements. However there sadly aren’t sufficient drones round at the moment for right kind mating.
Happily, by means of that point our closing rounds of nucs have constructed up into robust singles — and want a moment field of honey and brood. So we harvest many of the honey from the hives with second-year queens, and shake all of the bees down right into a unmarried, along side their brood. We then hit that unmarried with a powerful formic remedy — in most cases in 95°F climate — within the hope of getting rid of no longer best its mites, however its elderly queen as smartly, in order that we will then put that field of “blank” bees, brood, and honey on most sensible of a unmarried short of shops for the wintry weather.
OBSERVATION: Once we if truth be told attempt to kill growing older queens with formic in scorching climate, darned if part of them don’t simply chuckle at us.
This brings me again to a topic that I’ve written about prior to now [[1]] — is it the formic that if truth be told kills queens, or do the formic fumes induce the employees to kill their mom? This query has bugged me since Dr. Amrine posed it years in the past [[2]]. So when some alternatives arose in September, I carried out a few small experiments.
Experiment #2: Are you able to take away, after which reintroduce the queen?
Primarily based upon my discovering that lowering the first-day flash off of fumes from Formic Professional pads just about eradicated queen loss [[3]], I sought after to seem extra deeply into this phenomenon. I’ve spotted that when an afternoon or so, the bees develop into acclimated to the smell (and inflammation) of formic fumes and ceaselessly stroll proper over the pads. So I puzzled whether or not briefly taking out the queen right through the preliminary flash-off and acclimation procedure, after which reintroducing her after a few days, may scale back the “queen loss downside.”
So I ran a small experiment, which I’ll undergo step-by-step (Figures 4-10).
Fig. 4 At 5:00 within the afternoon on September 22, with temperatures within the mid-70s F, I got rid of the queens from ten hives and caged them with seven attendants every.
Fig. 5 The check hives had been all unmarried deeps with 9-10 frames of bees. Once I pulled the queens, I carried out recycled Miteaway II pads charged with 50% formic acid (which applies an acceptably robust dose to a unmarried), in a 1½” rim [[4]]. This picture was once taken at midday an afternoon and a part later, right through which the common evaporation price was once 35 grams in keeping with day. Be aware that by means of this time the bees had been smartly acclimated to the fumes.
Fig. 6 Within the period in-between I maintained the queens in an incubator at 86°F (30°C) and 55% RH, for 43 hrs. They every were given a small plug of stiff sweet for a meals supply, and I gave them a few drops of water each day.
At midday two days later I returned with the queens. To my marvel and dismay, two had died, with their heads caught to the sweet (I do not know why — their attendants had been positive). The others all looked to be wholesome.
The ambient temperature was once 75°F, with some guards preventing off yellowjackets and attainable robbers on the entrances. I gave every hive two puffs of smoke, and allowed their queen to stroll again into the doorway of her hive. (Some had been reluctant to stroll in, it appears in accordance with the smell of formic fumes emanating from the entrances.)
When I’d reintroduced all of the queens, I lifted the hive covers to measure the evaporation price of the pads right through reintroduction (~39 g/day). To my marvel, one queen was once already being balled at the most sensible bars (Determine 7).
Fig. 7 This queen had made her manner as much as the highest bars, the place she then were given balled! I disregarded the balling bees and reintroduced her on the front.
A part hour later, I tipped up the bins to investigate cross-check the ground forums, and once more appeared underneath the lids. 3 queens had been being balled at the backside forums (together with the sooner one), so I recaged them every with one attendant and driven their cages between two combs clear of the fumes. Two different queens had been being joyfully mobbed by means of their staff (one in a ball striking from a backside bar), however and not using a indicators of aggression.
Fig. 8 Those bees at the backside board had been satisfied for Mother’s go back. They mobbed her, however allowed her to stroll freely.
Fig. 9 3 colonies aggressively balled their queens, which I rescued, recaged, and positioned between two combs of bees.
A part hour later I repeated the inspections. One queen was once nonetheless being fortunately mobbed at the backside board, and in some other hive the bees had been balling one useless employee and one yellowjacket.
Fig. 10 5 out of 8 queens had been reaccepted with out factor.
The next day to come, 24 hours after reintroduction, I repeated the inspections (together with searching for useless queens in entrance of the hives). There was once one employee being balled, however no indicators of any queens useless or being balled. I re-inspected two days later. The 3 queens that I’d recaged because of balling had been useless, however the remainder had been fortunately at the combs.
Effects: Out of 10 queens, two died within the incubator, 3 had been balled and ultimately died in cages, and 5 had been reaccepted right through robust formic utility. How’s that for some other set of ambiguous effects?
So I ran some other experiment a couple of days later in some other backyard.
Experiment #3: Is it the formic or the bees that kill the queen?
The queen is the biggest, supreme fed, and longest-lived bee within the hive. So why would she be extra prone to formic fumes than would expendable staff? To look whether or not that was once certainly the case, I uncovered some queens and staff, aspect by means of aspect, to precisely the similar formic fumes.
By means of now it was once overdue September. I arrange ten hives with second-year queens in unmarried deeps containing 8-9 frames lined with bees. I stuck and marked the queens, then positioned them in push-in cages halfway down a comb, off heart, however underneath a recent formic pad. The cages had been positioned over comb and not using a brood within, however with open nectar (in order that the queen would no longer be dependent upon the employees to feed her), and with 3 staff as attendants. All cages had been positioned going through a comb of brood, in order that the caged bees would stay throughout the cluster. I carried out MAII formic pads in early afternoon, made with 50% formic, in a 1.5″ rim. Temperature was once ~80°F.
Fig. 11 It’s simple to make a to hand push-in cage out of a wide-mouth Mason jar rim, with 1/8” {hardware} fabric soldered or glued in position. (I haven’t but attempted it, however 5-mesh {hardware} fabric could be used to serve as as a queen excluder.) I incorporated 3 staff from the brood space with every queen, and positioned the cages over open nectar, midway down the brush, underneath the formic pad.
After a number of days, the formic had evaporated from the pads, and I inspected the cages to peer how the caged queens and staff made out.
Effects: 8 out of ten queens survived and appeared positive. However within the cages of the 2 that died, the attendants had been nonetheless alive. So some queens do seem to be extra prone to formic fumes than are staff. However 8 out of 10 possibly outdated queens tolerated being trapped underneath a powerful formic remedy simply positive.
Dialogue
Formic acid has some very fascinating qualities as a mite remedy:
- It’s rapid appearing (you’ll do away with maximum all of the mites in a hive in a single day with a powerful flash remedy).
- A robust dose can penetrate the cappings.
- It doesn’t contaminate the combs or honey.
But it surely additionally has its downsides:
- In scorching climate it is going to induce queen loss — despite the fact that I’m nonetheless no longer transparent whether or not the vast majority of the ones losses are immediately because of the fumes, or as an alternative from being balled by means of their daughters. (Protecting the higher aspect of Formic Professional strips with their wrapper will in large part do away with queen loss in scorching climate.)
- Formic additionally shows nice hive-to-hive variability in efficacy when it’s scorching.
Formic is a smart selection in early spring, since you’ll use it to create a brief brood wreck to cut back swarming, and if a queen will have to be misplaced, the colony can simply rear a alternative at the moment of season. However later within the season, because of loss of drones in my space, I’m involved that any alternative emergency queens may no longer get correctly mated.
Anyway, formic’s been used for a few years, particularly in Europe and Canada (the place there’s a larger collection of licensed utility strategies). I will best hope that now that the EPA has spoken, that our state regulators will let us experiment with the generic liquid extra freely.
Citations and Notes
[1] Oliver, R (2022) Formic Professional and queens In scorching climate. American Bee Magazine September 2022 https://scientificbeekeeping.com/formic-pro-and-queens-in-hot-weather/
[2] Amrine Jr, J, & R Noel (2006) Formic acid fumigator for controlling varroa mites in honey bee hives. Global Magazine of Acarology 32(2): 115-124.
[3] Oliver, R (2022) op cit
[4] This isn’t an licensed approach for varroa regulate, however since I used to be no longer making use of the formic for pesticidal functions, it was once no longer a criminal offense.