jones_supa writes: The research to find out why bees are disappearing continues. After initial spurious claims about cell phones causing the problem, researchers began identifying factors that did create problems for the health of bees, including infections, insecticides, and agricultural practices. The problem is that all of these seemed connected to colony collapse, which suggested the cause was likely to be complex. Now, some researchers may have cut through some of the complexity. They've found that a specific class of insecticides — neonicotinoids — cause changes in the immune system of insects, which in turn leaves them more vulnerable to infection. The scientist have begun the process of determining how those immune changes come about on the molecular level. The results will also provide further support for the European Union's attempt to ban the use of neonicotinoid pesticides, a decision that was made earlier this year.