While several possible causes are identified, including "natural" causes like fungus, mites, and disease, commercialization and spreading suburbanization also seem to be culprits. Even though a fungus attack on bee colonies might seem like a natural first cause of "general stress collapse," the bees' susceptibility might be being increased by industry:
Bee pollination is increasingly a highly concentrated industry. Rather than a dispersed system of local hives, a few commercial operators now haul tens of billions of bees from coast to coast in 18-wheelers .... First, the bees themselves have been bred into single-purpose superpollinators, rather than bees with multiple functions (make honey, feed the queen, maintain the hives, and extend the species). The industrial bees have lost the diversity and natural traits of wild bees.It appears that the industry is trading long-term colony health for short term bucks.
Second, constant trucking puts stress on the bees, suppressing their immune systems and making them vulnerable to viruses, mites, and diseases. As part of their forced migration, the bees are fed a limited diet of high fructose corn syrup–about as healthy as humans trying to live on Cokes.
But suburbia--which is rarely accused of promoting too much diversity--the destruction of natural habitats with sprawl, and the increased and indiscriminate use of lethal and maiming pesticides in order to have that "perfect lawn" to drive home to may also be the cause of colony collapse. Thanks to our own avarice and vanity, we face an impending crisis that money may not be able to buy our way out of.