Now I'm forgetting where I heard or read this, but I thought one recently popular pesticide acts by disorienting the bugs. Some bee keepers have pointed out that this is exactly what is happening to bees--they can't find their way back to the hive. They just go away and never come back.
There is currently a working group studying "Colony Collapse Disorder," the formal name for the phenomenon. "Participating organizations include the USDA/ARS, the Florida Department of Agriculture, the Pennsylvania Department of Agriculture, Pennsylvania State University, and Bee Alert, Inc., a technology transfer company affiliated with the University of Montana. Broadly this group has identified its mandate as: 'Exploring the cause or causes of honey bee colony collapse and finding appropriate strategies to reduce colony loss in the future.'" website
Colony Collapse Disorder (CCD) is the name that has been given to the latest, and what seems to be the most serious, die-off of honey bee colonies across the country. It is characterized by, sudden colony death with a lack of adult bees in/in front of the dead-outs. Honey and bee bread are usually present and there is often evidence of recent brood rearing. In some cases, the queen and a small number of survivor bees may be present in the brood nest. It is also characterized by delayed robbing and slower than normal invasion by common pests such as wax moth and small hive beetles.
[According to the CCD report
] "If bees are eating fresh or stored pollen contaminated with [neonicotinioid pesticides] at low levels, they may not cause mortality but may impact the bee's ability to learn or make memories. If this is the case, young bees leaving the hive to make orientation flights may not be able to learn the location of the hive and may not be returning causing the colonies to dwindle and eventually die."
*Imidacloprid = Bayer; trade names Merit, Admire, Gaucho, Confidor, Premise, Touchstone and Winner, Hachikusan (in Japan) and Premise for termite control, and Advantage in the US and Europe for flea control on pets.
*Clothianidin = Bayer; trade names Clutch, Prosper, Poncho, ArenaTM
*Thiamethoxam = Syngenta; trade names Cruiser, Platinum, Helix
But just as devastating to bee stocks as CCD are tracheal mites and Varroa
mites which were introduced to North America in the 80's and endemic bacterial diseases which have recently become antibiotic-resistant (American foulbrood). Both have become widespread in the last decade or two. Mites were responsible for over a 70% colony loss rate in 95'-96' and 00'-01' in the northern states.