Free Access
Volume 30, Number 4, 1999
Page(s) 289 - 292
Apidologie 30 (1999) 289-292
DOI: 10.1051/apido:19990404

Negative long-term effects on bee colonies treated with oxalic acid against Varroa jacobsoni Oud.

Mariano Higesa, Aránzazu Meanab, Miguel Suáreza and Jesús Llorentea

a  Centro Apícola Regional, Servicio de Investigación Agraria de Castilla-La Mancha, Marchamalo, Guadalajara, Spain
b  Dpto. Patología Animal I (Sanidad Animal), Facultad de Veterinaria, Universidad Complutense de Madrid, Avda Puerta de Hierro s/n, 28040 Madrid, Spain

Abstract - Two oxalic acid treatments were given to five colonies in autumn and five colonies in spring. In each treatment, colonies were treated every 7 days for 4 weeks with a 3 % sprayed oxalic acid. Another five colonies in each season served as controls and were sprayed only with water. Efficacy of oxalic acid in autumn was 94 % and in spring was 73 %. A long-term study of the colonies for 3-4 months after the last application of oxalic acid showed a statistically significant negative effect of the acid on brood development. In addition, three queens died in the treated colonies. © Inra/DIB/AGIB/Elsevier, Paris

Key words: Apis mellifera / Varroa jacobsoni / oxalic acid / brood development