It was discussed previously (in 2007) in:
Colony Collapse Disorder
Could not find it but recall citing a study that was performed in cooperation with an Army chemical lab. That study identified a fungus as complicit in this bee colony collapse.
How would that family of insecticides correspond to this fungus?
Of course, another unanswered question is whether the neonicotinoids industry is subverting research to protect profits. Only corrupt (communist) organizations protect profits at the expense of customers and society. Because that is what the business schools teach.