Sustainable Beekeeping: Gasifier of Oxalic Acid

Finalist 2013

Associação Dos Apicultores De Caçador e Região- ACAP
Av Barão do Rio Branco, 327 C/ACIC Caixa Postal 1004 - Centro
(49) 3563-0612
Responsible for technology
NamePhoneEmailSocial Networks
Walter Bartholet(49)
Technology Summary

A gasifier of oxalic acid that uses no generator or battery, employing the beekeeper’s own smoker as a gasifier, has ideal effectiveness and enables the application of the exact portion of acid to fight the Varroa destructor mite. It makes possible to biologically control this parasite in africanized honeybees.

Main Theme


Problem Solved

The applications of technology to raise africanized bees did not bring satisfactory results in the last decades. In 2007, ACAP managed to prove that the Varroa destructor mite causes damages to the hives of africanized bees. Tests performed with this treatment of oxalic acid during two years resulted in reduced loss of beehives and greater productivity, when compared to hives that were not treated against Varroa. Starting in 2009, it was shown that our africanized bees really have sanitary problems, reflected in the high losses recorded nationally. Many researchers indicate that pesticides, environmental pollution, virotic and bacterial diseases are the main cause for the losses. Our own experience shows that, keeping the Varroa presence low in the hives, we can prevent diseases and future losses of bees. Unfortunately, keeping Varroa under control is now a challenge for beekeepers in the whole world. Of the many forms of control, one has stood out in the latest years: the use of gasified oxalic gas. The ACAP’s challenge was to adapt this technology to the reality of our beekeeping activities.

Solution Adopted

The ectoparasitic mite called Varroa destructor is currently the most damaging plague to apiculture in the world. Initially classified as Varroa jacobsoni, it was described for the first time in 1904 and later renamed as Varroa destructor. Varroa is a natural parasite of the Apis cerana in the South of Asia, but it is now disseminated in all continents, except Australia and New Zealand. It causes huge losses in professional apiculture and affects adult and young bees, now being a parasite of all the subspecies of Apis mellifera. It transmits diseases and brings imbalance to the bee castes. In Brazil, this plague was introduced in 1972 and quickly spread to all the national territory. It was just at a time when Brazil was reactivating national apiculture, adapting or developing new techniques to deal with africanized bees. This adaptation of the africanized bee meant, in practical terms, letting it reproduce naturally, avoiding the creation of artificial swarms and raising queens with the use of a minimum of techniques, because the africanized bees rejected them all. The development of the SC Brasil Smoker to treat these bees is a symbol of that time. After 2001, when there was a growing international demand for Brazilian honey, management techniques started to be implemented, such as artificial feeding, raising of queens, migration to productive forests and artificial swarming, that interfere in the bee’s natural cycle and facilitate the multiplication of Varroa and several diseases. The rates of Varroa infestation have grown in the latest years and, in some regions of Brazil, are similar to those observed in Europe. In the last five years, it is suspected that Varroa may have been responsible for more than 50% of the losses of hives in this country.To minimize the effects of Varroa infestations, several synthetic acaricides were developed, like the organophosphates and pyrethroids used in other countries. However, the continued use of these products resulted in high levels of resistance in the mite population, not to mention the possibility of contamination of the honey and wax in the interior of the colonies. Such situation stimulated strategies to minimize the mite resistance and the accumulation of chemical residues. There is a growing interest, among researchers and apicultors, in alternative ways to fight plagues and diseases, among which is the control of Varroa with natural products. Among these the favorite is oxalic acid. Like all medications, its proper dosage and application is essencial for effectiveness. Since 2007 ACAP has tested organic acids and ethereal oils in beehives and had the best results with the use of oxalic acid, independently from the form of application: sprayed in water, applied in syrup form or gasified. After four years of tests with this acid, we developed our own gasifier of oxalic acid, after a simple modification in the smoker. We use a can with a handle inside the smoker. The oxalic acid is weighed and placed in a paper sachet: 2 grams of acid for weak hives; 3 grams for strong hives; 1 gram for nuclei and swarms. The smoker is lit normally, using charcoal up to half of the container. Then the can is placed and some more charcoal is placed around the can. When the can’s bottom is above 100° Celsius the work can start, with a sachet adequate for the purpose, capping the smoker and activating the bellows to pump oxalic gas into the beehive. With some practice, the treatment of each hive may last approximately one minute. We advise two to three treatments at the beginning of the intercrops and two to three at the end of each crop, always searching the moment when there are no capped broods, for maximum effectiveness.

Technology Attachments
informações gerais da apiculturaBaixar
Modelos de Gasificadores de outros Paisesdownload
Varroa Moralidade e ração natural das abelhasdownload
produçao de mel apartir de 1989Baixar
de 2005 a 2010 poucos avanços na produção queda nos ultimos dois anosBaixar
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Last modified date: 9/16/16 11:49 AM