(They have known what the cause is for a while, but the reason it hasn't been death with is the usual reason. Money.)
Germany and France Ban Pesticides Linked To Bee Deaths; Geneticist Urges U.S. Ban
http://www.enn.com/top_stories/article/37493Collapse Disorder (CCD), at least one key bee expert is calling for a ban of the same pesticide in the United States. "In the United States, drastic action is needed," says Canadian geneticist Joe Cummins, explaining that U.S. farmers and beekeepers shouldn't have to wait for more evidence or for an air-tight explanation for the complex syndrome, which threatens one in every third bite of food in the United States. Now most apiarists and scientists realize that pesticides are a factor in CCD, he says.
Cummins' remarks, in an interview with GreenRightNow,
come less than a month after Germany's ban of clothianidin, a pesticide commonly used to keep insects off of corn crops. Germany banned the pesticide after heaps of dead bees were found near fields of corn coated in the pesticide, and in response to scientists who report that the insecticide severely impairs, and often kills, the honeybees that corn and other crops depend on for pollination.The German government took the extraordinary action to protect bees and other essential pollinators, stating that there is now enough compelling evidence connecting the chemical to Bee Colony Collapse Disorder (CCD) in that country.
The ban also will likely fuel the European debate over genetically modified food, which involves treating crop seeds to resist harm from pesticide treatments. Critics of such modified foods say they are harming the environment, and have unknown human consequences, for little or no crop gain. Some scientists in Europe have called for their ban.
(there were only 4 paragraphs for this particular article)
http://www.epa.gov/opprd001/factsheets/clothianidin.pdf(it's used primarily on corn crops and apparently works very well. And it's made by Bayer. Since Monsanto has had control of the corn and soy crops in the US for at least 20 years, is there any wonder why it hasn't been banned in the US?)
Here is the google search on link after link for people calling for it's ban. So far, the US gov't has had deaf ears to it all.
http://www.google.com/#sclient=psy&hl=en&rlz=1R2ADRA_enUS404&q=us+ban+on+Clothianidin&rlz=1R2ADRA_enUS404&aq=&aqi=&aql=&oq=us+ban+on+Clothianidin&gs_rfai=&pbx=1&fp=e4d4d211f0ded287And lastly, here is the EPA's responce...
http://food.change.org/blog/view/epa_defends_approval_of_bayers_bee-killing_pesticide"EPA recently received a letter from the National Honey Bee Advisory Board and other organizations requesting that the Agency remove clothianidin from the market. That letter and subsequent press coverage contain several erroneous statements. Reports that a clothianidin honeybee field study is a "core" study (that is, a study routinely required to support the registration of a pesticide) are not true. Further there is confusion about the review status of the study.
EPA scientists routinely reevaluate studies to determine whether the information submitted is valid and if it is relevant or useful to the regulatory matter in question (in this case a request for a new use). While this study was thought to be invalid as cited by the above groups, EPA reevaluation of the study determined that it contains information useful to EPA's risk assessment. This field study revealed the majority of hives monitored, including those exposed to clothianidin during the previous season, survived the over-wintering period."
So while France and Germany ban the pesticide, and the National Honey Bee Advisory Board say ban it, the EPA sees no reason to.
The piece goes on to highlight the inaccuracies in the EPA's position.
In the end, like all things, it comes down to money.