The disorder is now officially known as 'Autumn Collapse', but has also been called 'disappearing disease' because no sick or dead bees could be found in failing colonies.

H. LEN FOOTE
Supervisor of Apiary Inspection
Calif. Dept. of Agric.
Sacramento, Calif.

DURING RECENT winters beekeepers in some parts of California have been puzzled by what appears to be a rather rapid disappearance of bees from their hives. Strong colonies, heavy with honey and pollen, apparently at their prime for overwintering, suddenly start to decline for no apparent reason during autumn, and collapse within six weeks . The disorder is now officially known as "Autumn Collapse" but has also been called "disappearing disease" because no sick or dead bees could be found m failing colonies. The disorder has caused loss of up to 90 per cent of the colonies in affected apiaries. Similar losses have occurred in parts of Louisiana, Texas, Alabama and New Mexico.

The disorder was first noticed during the winter of 1961-62 when affected colonies were found at a number of locations in the Sacramento Valley, including research colonies at UC Davis. Similar losses occurred in USDA research colonies at LSU, Baton Rouge, Louisiana. The disorder has recurred in some apiaries and in certain locations; but occasional apiaries remain normal in areas where most apiaries are severely affected. California beekeepers lost an estimated 10,000 colonies to Autumn Collapse last winter (1964-65) .

Early investigations were limited by our inability to obtain a sufficient number of sick or dead bees for testing. The few surviving bees found in affected colonies usually showed no signs of sickness or distress. Extracts prepared from their macerated tissues produced no disease symptoms in healthy bees. A fungus, Aspergillus repens, isolated from a sick bee in 1962 failed to be pathogenic in bee feeding studies.

Pesticide residues were found in honey and / or pollen stores of some affected colonies, but not others. Bees could be re-established without apparent loss on combs previously occupied by a colony of bees which had succumbed to Autumn Collapse.

Foote, H. L. (1966). The mystery of the disappearing bees. Glean. Bee Cult., 94: 152-153; 182.

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