The varroa  bee mite has developed resistance to the chemicals used to kill it and is passing that resistance to beehives through the country, with bee experts saying, unless beekeepers change the type and frequency of the chemicals they use to combat the disease, it will have catastrophic consequences. The mite first reached New Zealand in 2000 and the bee industry, which is worth about $60 million, spends about $16m each year fighting varroa.