Newest oxalic acid researhes

[Finman]

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European Varroa Group tested best varroa killing method in years 1998-2006.

After that European countries have not done developing work in this area and resources have moved to the project of honey bee wellfare . And it is COLOSS project.

Many countries have researches those results to see, how methods work in their circumtancies.

.This forum has taken a line that it is better to "ques" than find out, how things are or what numbers are. There are no responsibility to deliver that kind of thinking and so I started to collect here newest information about varroa control.

 

[Finman]

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M. Rashid, E. S. Wagchoure, A. U. Mohsin
*
, S. Raja and G. Sarwar
Honeybee Research Institute, National Agricultural Research Centre, Islamabad,

Pakistan
*
Department of Entomology, PMAS University of Arid Agriculture, Pakistan
Corresponding Author: E-mail: [email protected]

ABSTRACT

The research work was carried out to determine the effects of oxalic acid (OA) on reducing ectoparasitic mite Varroa
destructor Anderson and Trueman (Acari:Varroidae) populations in honeybee Apis mellifera linguistica (Hymenoptera:
Apidae) colonies in the fall at Honey bee Research Institute, National Agricultural Research centre, Islamabad.

Twenty (20) honeybee colonies were used in this experiment. Colonies were divided into four groups of five colonies each.

Oxalic acid was applied in sugar syrup with 4.2, 3. 2 and 2.1% concentrations. The OA with different concentrations was trickled
directly on the adult honey bees in between two frames using a syringe applied thrice on different dates at five days
interval.

Average efficacy of OA with 3.2, 4.2 and 2.1 % was 95%, 81% and 46 % respectively.
No queens were lost, and there was no adult honeybee mortality in any of the colonies during the experiment. It can be concluded that 3.2% OA
concentration are very effectively control varroa mite and can be used without any side effect during broodless condition.

http://www.thejaps.org.pk/docs/v-22-1/31.pdf

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[parkranger]

Surely I am reading this incorrectly? OA applied to the same seam of bees three times within 15 days?

 

[Finman]

Oxalic acid toxity on bees

Prueba de Toxicidad Aguda por Contacto de Ácido Oxálico en Abejas de la Zona Sudoeste de Uruguay
Leonidas Carrasco-Letelier1*, Yamandu Mendoza1, and Gustavo Ramallo1

1Instituto Nacional de Investigación Agropecuaria (INIA), Estación Experimental Alberto Boerger INIA La Estanzuela, Ruta 50, km 11, Colonia, Uruguay. "Corresponding author ([email protected]).


This work studies the acute contact toxicity of oxalic acid (OA) on a honeybee polyhybrid subspecies is work stud(Apis mellifera), which is the dominant biotype in southwestern zone of Uruguay (SWZU) and the country's most important honey-producing region.

We determined the mean lethal dose (LD50), as well as the no observed effect level (NOEL) and the lowest observed effect level (LOEL) values. We also estimated the total number of honeybees per hive in the test area.

The aim was to assess the relationship between the maximum OA dose used in Uruguay (3.1 g OA per hive) and the toxicological parameters of honeybees from SWZU. The current dose of 3.1 g OA per hive corresponds to 132.8 OA per honeybee since determined NOEL is 400 OA per honeybee;

our results indicate that the current dose could be increased to 9.3 g OA per hive. The results also highlight some differences between the LD50 value in SWZU honeybees (548.95 OA per honeybee) and some published LD50 values for other honeybee subspecies.

http://www.scielo.cl/scielo.php?pid=S0718-58392012000200019&script=sci_arttext

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Crarification by Finman

7,5 g oxalic acid is ment to 5 one boxe hives or 3 two boxe hives.
So to 2-box hives dosage is 2,5 g per hive.
.

 

[Finman]

EFFICACY OF DIFFERENT ECOLOGICAL METHODS
FOR HONEYBEE (APIS MELLIFERA) VARROA PREVENTION IN SPRING

Vidmantas Pileckas
Gintautas Juozas Švirmickas
Violeta Razmaitė
Mindaugas Paleckaitis
Institute of Animal Science of Veterinary Academy, Lithuanian University of Health Sciences

year 2012

Abstract.
The study was carried out with the aim to examine the efficacy of naturally occurring chemicals and mechanical methods for honeybee (Apis mellifera) varroa prevention in spring and infestation dynamics during the active season in the treated and untreated colonies under practical Lithuanian beekeeping conditions.

Forty (40) colonies were used for formic and oxalic acid, sugar syrup, drone comb trapping treatments and monitoring of the dynamics of
varroa infestation.

The effect of the oxalic acid treatment was higher than that of the formic acid. However, the formic acid treatment showed higher negative effect on honeybee mortality than the oxalic acid treatment.

The honeybee drop after the first and second applications was, respectively, 15 times and 16.8 times higher compared with the oxalic acid
treatment.
Honeybee sprinkling with sugar syrup increased mite drop 2.5-2.7 times compared with the natural mite
drop. However, it also increased the attraction of honeybees to rob foragers.

Drone comb trapping significantly reduced infestation of honeybee colonies and it also increased aggressiveness and disorientation of honeybees.
Monitoring of infestation dynamics in the treated and untreated colonies showed that during the summer the infestation of untreated honeybees increased 1.7 times.

Oxalic acid treatment in spring did not protect from varroa
spread. Although after a week in the oxalic acid treated colonies the infestation of honeybees decreased 5.6 times,
afterwards the infestation of initial level of infestation.

 

[Finman]

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COLOSS booklet 2012

Summer treatment against varroa mites with oxalic acid on artificially broodless colonies
Antonio NANETTI
Giorgio BARACANI
Andrea BESANA

CRA-API, Research Unit of Apiculture and Sericulture, Via di Saliceto 80, 40129 Bologna, Italy,

Beekeeper Association of Bologna, Italy

In spite of the large efforts made in the past decades to put the varroa infestations under control, this major upset for the apiculture worldwide is far to be resolved. The control concepts may change according to local conditions but, generally, the narrow range of available acaricides implies that a combination between different substances and/or techniques must be
used by the beekeepers. Pharmacoresistance against the acaricides and the restrictions for organic beekeepers make the multifaceted problem of varroa control even more complicate.

The various substances that can be used against the varroa are subject to limitations in their application. For instance, the oxalic acid -one of the most important natural acaricides- is suitable to hit varroa mites that are in their phoretic stage at the moment of the treatment, whereas the reproducing mites in the brood cells do not have contact with effective doses of the acid.

As a consequence, oxalic acid is used very frequently by beekeepers of non-temperate regions during the winter, when a natural brood interruption occurs.We could set-up a new technique for the control of varroa infestations with oxalic acid during the summer, normally impeded by large amounts of brood in the colonies. By a prolonged queen confinement a broodless condition is induced, forcing varroa mites to the phoretic stage. The oxalic
acid administration is then performed by the trickling technique.

Replicate tests were made in different years and locations in Italy to measure efficacy against the mites, tolerability at individual level, colony reactions, queen survival to the manipulation etc. with highly promising results. Based on them, the extension to the field practice has been initiated.
The new treatment technique offers a new tool for beekeepers to control varroa infestations in summer.
It appears as highly robust to the environmental variables that were taken into consideration until now;
nevertheless,

 

[Little John]

Some more sources:

http://www.apimondia.com/apiacta/articles/2003/nanetti.pdf
http://www.agroscope.admin.ch/imkerei/00316/00329/02081/index.html?lang=en
http://www.agroscope.admin.ch/imkerei/00316/00329/02083/index.html?lang=en

The last one is re: Essential Oils - useful for comparison ?

LJ

 

[Finman]

Some more sources:

http://www.apimondia.com/apiacta/articles/2003/nanetti.pdf

LJ

When Nanetti wrote this lecture 2003, the results are from years 1998-99.
These experiments were the first what European varroa Group handled and what the group started to verify.

This link is old in varroa science

Trickling stuff has been 4,2% and sugar content 60%. After that the systems have changed and we know those results.

But if in the bottle is number 6% it is 6%, and not 4,2.

And if number is 4,2% it is not 3,5%.

And if percent stuffs have measured as weight, it is weight%.

That soffa reseach has went too far in this forum.

.

 

[Finman]

Some more sources:

The last one is re: Essential Oils - useful for comparison ?

LJ

There are numerous "essential oils". Only which is recommended is thymol.

Thymol based commercial producst are many.

- If you have couple of hives, try to stay what is wiser have recommended.

- If you have 30 hives, you surely know what you are doing. Life has teached then enough.

 

[alanf]

CONTROL OF ECTOPARASITIC MITE VARROA DESTRUCTOR IN HONEYBEE (APIS
MELLIFERA L.) COLONIES BY USING DIFFERENT CONCENTRATIONS OF OXALIC ACID
M. Rashid, E. S. Wagchoure, A. U. Mohsin*, S. Raja and G. Sarwar

http://www.thejaps.org.pk/docs/v-22-1/31.pdf

Thanks for the links.

But if in the bottle is number 6% it is 6%, and not 4,2.
And if number is 4,2% it is not 3,5%.
And if percent stuffs have measured as weight, it is weight%.

Do you get the Enolapi Italian manufactured bottles in Finland? It's the most widely available premixed oxalic treatment in the UK. The percentage calculation on the Enolapi bottles is not the same as the percentage calculation in the papers you quote (Rashid et al, who cites Nanetti, Prandin and many others). The percentage calculation on other manufacturers' bottles, where enough detail is given, use the same calculations and percentages as those papers. Enolapi do it a different way. It was pointed out to me recently that one supplier, at least, makes some effort to acknowledge that different percentages are quoted for the same formula:

Oxalic Crystals... Disolve 1kg sugar in 1 litre of water. This produces 1.67 of 1:1 (100%)syrup. Add 75grm of Oxalic Acid Dihydrate. This gives a 3.2% Oxalic Acid (weight/volume) solution which is more commonly expressed as 4.5% Oxalic Acid Dihydrate solution.

Google the paragraph or look it up on the Wynne J0nes site, it's for oxalic crystals supplied by Enolapi.

 

[Finman]

Thanks for the links.

Do you get the Enolapi Italian manufactured bottles in Finland? .

Resellers make own dilution here. There is no idea to import that kind of stuff.

We have no problems to understand what percentage is. We can trust here that it is proper.

Our main company sells
- oxalic syrup half litre 5 euros .......to 6-10 hives

- 75g oxalic acid 2.50 euros (to 30-50 hives)...........you add 1 kg sugar and 1 kg water

- 1 kg 12 euros

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[MuswellMetro]

Resellers make own dilution here. There is no idea to import that kind of stuff.

We have no problems to understand what percentage is. We can trust here that it is proper.

Our main company sells
- oxalic syrup half litre 5 euros .......to 6-10 hives

- 75g oxalic acid 2.50 euros (to 30-50 hives)...........you add 1 kg sugar and 1 kg water

- 1 kg 12 euros

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thst's extatly the ratio of oxalic / sugar/water recommended in the UK and is what most uk beekeepers would use as the main retailer of made up solution and the NBU recommendation are the same....it is just one or two suppliers that import the Italian stuff that are confusing the ratio/%

 

[Finman]

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This is huge!
One litre oxalic trickling stuff and PRICE £ 36

 

[alanf]

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This is huge!
One litre oxalic trickling stuff and PRICE £ 36


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It is expensive. It has been driven in a truck from Germany, there were only two bottles. One bottle for the photo and one for the shelf. If it was cheaper they might sell it and that would need another truck journey.

 

[Finman]

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Inhaltsstoffe von Original BienenWohl: Zuckerlösung, 3,5 % Oxalsäure, Propolis, Zitronensäure, Alkohole, ätherische Öle.

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in Germany price is 25 euros


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[Floyd]

Can get it for £19 from here

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[Finman]

Can get it for £19 from here

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and its real value is 2 pounds

 

[alanf]

Inhaltsstoffe von Original BienenWohl: Zuckerlösung, 3,5 % Oxalsäure, Propolis, Zitronensäure, Alkohole, ätherische Öle.
in Germany price is 25 euros.

Ingredients of Original Bienenwohl: sugar solution, 3.5% oxalic acid, propolis, citric acid, alcohols, essential oils.
Cheap ingredients, expensive package. Even if you collect it yourself from Germany.

A block treatment means the application of three treatments, at 6 – 7 day intervals, e.g. on 2nd April, 8th April and 14th April, thus ensuring that the bees – and mites – are also treated from the brood phase. A second block treatment is then administered immediately after the removal of the first honey crop. For us, this harvest is in the first week of June. We then administer a third block treatment before taking the bees to the heather, around 10th August. We also do a block treatment after the heather forage period, around 6th to 8th September. Single treatments are administered in October/November, depending on the infestation level and the outside temperature (never administered when below 10 degrees). Clearly, this also depends on reinfestation levels.

From http://www.bienenwohl.com/eng/dl/readersletterbienenwohl.pdf

That's 12 or more 10-15ml oxalic treatments per year. One litre per year for five to eight hives, but I'd be wary of storing it for long outside a freezer. In addition they use 'Knabba' strips in summer - thymol and eucalyptus on a paper base (no dose or exact timing I could see but 7.95 euros for a pack of 6).

Not cheap and a lot of intervention.

 

[Finman]

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The base is 3,5% oxalic acid and promised efficacy is 96% as in usual oxalic dripling.

Other chemicals are harmless ingredients. Harsh business I would say.
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[yzalich]

Hi
So I'm a new kid on the block! However I have been using OA in various form since 1999, working with 30 colonies. The 3.5% solution being discussed does not need a sugar component. Oxalic acid dihydrate crystals costs £5 -£6/500 grams. This will produce some 14 litres of 3.5% solution; enough for 280 treatments. Buying 'branded' OA solution is a no brainer!