Within the technical model, attention goes primarily to diseases and parasites. Over the years, in succession, the Varroa mite (from 1980), Nosema (from approximately 1990), and viruses (from approximately2000) have been indicated as the main cause of bee decline. Due to the many studies being conducted worldwide, every 6 months a new disease or parasite is discovered among bees. It will not be possible to all combat all of these, if that would even be desirable.
By far the most attention is paid to the Varroa mite* which has been the subject of research for the longest period. Perhaps this is why the Varroa mite alone is considered the main problem. Worldwide, the Varroa is the subject of much discussion and many publications:
(number of hits, end 2012) Google Google Scholar
“Varroa” 976,000 13,200
“Varroa destructor” 198,000 4,110
“V. destructor” 16,700 1,060
* in the Netherlands (approximately 8,000 beekeepers), since the 1980s, an estimated EUR 4 million has been spent on research into this parasite.
Relationships, not causal relationships
When seeking the causes of bee decline, scientists have focused on finding relationships between the level of bee decline and all kinds of factors, but not on causal relationships. A very pertinent example can be found here. Key questions, in particular why the Varroa mite has been able to establish itself and spread, however, are not asked and thus not answered.
Varroa control does not help
It can be observed that the effort to control the Varroa mite with all kinds of resources has not helped to maintain bee decline at normal levels. It is therefore justifiable to argue that research into diseases and parasites affecting bee colonies - an approach from the disease-model - has reached a dead end. The problem is not so much the individual pathogens, but the underlying causes.
From the scientific research conducted to date, no clear cause for bee decline has been identified. However, consensus has been reached in the statement “a complex of factors is responsible for bee decline”.