In Canada - honey bees work alfalfa (in bloom) for nectar (producing a mild white honey) - few of these visits result in pollination (I've heard 1 in 100) - for alfalfa seed production, bees other than honey bees are necessary. Alfalfa leafcutter bees are used whenever alfalfa seed is being produced. The difference in seed yield with leafcutters is 3 to 10 fold. I've seen remarkable aerial photos of alfalfa seed fields, where petal fall on pollinated alfalfa shows up clearly. The difference in petal fall relative to the leafcutter nesting shelters is unmistakable. If flying conditions are marginal, pollination is good only around the shelters. With very good flying weather, the whole field is more evenly pollinated. The NE B.C. and NW Alberta Peace River region has no chalkbrood in the leafcutter population. I've talked to alfalfa seed producers in SW US who prefer to use honey bees for pollination, because honey bee colonies will recover after an insecticide hit, while leafcutters are affected over a longer period. The growing conditions, temperature etc are also different, and perhaps then, more than 1 % of honey bee visits results in pollination. Insecticides are not often used in alfalfa seed production in the northern region. Kerry Clark, Apiculture Specialist B.C. Ministry of Agriculture 1201 103 Ave Dawson Creek B.C. V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299 INTERNET [log in to unmask]