>Subject: sunflower pollination
>
>Does anyone have information on sunflower pollination?
 
You're apparently assuming that the only bee worth managing for pollination
is Apis - in North America, there are some 130 native bee species that
*only* visit sunflowers, and at least another 150 that will visit it for
pollen when available (and all almost undoubtedly act as effective
pollinators). It wouldn't surprise me if somewhere in those hundreds of
species there are a few that are more effective than honeybees. Some
colleagues and I have published a paper (Ecology 75: 1406-1419, 1994) on
one of the most widespread sunflower specialists, Dieunomia triangulifera
(Halictidae), whose activity is synchronized on both a seasonal and daily
basis with sunflower bloom. Out of 500 floral visitors to Helianthus annuus
assayed during our study, only 4 were Apis, the rest were native bees (D.
triangulifera and Bombus pensylvanicus together representing about half of
the total), and they were able to effectively strip all pollen from the
plants by mid-day and give essentially complete seed set. I would
respectfully submit that it does NOT require Apis to pollinate a field of
sunflowers if one has native bees nesting nearby. They also cost nothing to
manage, aside from some sandy soil where they can nest.
Just something to think about,
 
Doug Yanega      Illinois Natural History Survey, 607 E. Peabody Dr.
Champaign, IL 61820 USA     phone (217) 244-6817, fax (217) 333-4949
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82