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
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