Max Watkins ha scritto:

>
>
> Coumaphos resistance is now widespread in Italy also.
>

hello
http://www.apicolturaonline.it/milani.htm
Sviluppo di resistenza ai fosforganici in Varroa Jacobsoni?

Summary
Adult female Varroa jacobsoni mites were sampled in the province of Reggio
Emilia (Northern Italy), where field trials had
shown a decreased efficacy of Perizin in some apiaries, and assayed for
resistance to coumaphos by using a laboratory test. In
some samples, the tolerance at 20 ppm coumaphos was significantly larger than
that observed in a reference susceptible
population; 1.5% mites of the mites assayed at 50 ppm survived (expected
survival in a susceptible population ~ 0.1%), but all
the 430 mites assayed at 100-500 ppm died.
These data show an increase in the tolerance to coumaphos at least in some
apiaries, but do not make it possible to conclude
that a small proportion of highly resistant mites is present.
Giorgio Della Vedova*,Marco Lodesani**,Norberto Milani*
*Dip. di Biologia applicata alla Difesa delle Piante,Università di Udine
**Istituto Nazionale di Apicoltura,Bologna.
Da l'APE NOSTRA AMICA numero 1 gennaio-febbraio 1997


Dossier Varroa file pdf
http://www.apicolturaonline.it/DossierVarroa.pdf

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Giacomo Omallini
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