In a message dated 3/4/00 6:50:03 AM, [log in to unmask] writes:

> Implies that "native pollinators" are more benign than honey bees.
Bumblebees will chew out the base of a flower evolved to be pollinated by
hummingbirds and other large "imperiled" pollinators to get at the nectar
there without pollinating the flower. Honey bees won't do that.

I offer the following long quote from an article published by the
Environmental
News Network last year as an example:

Researchers investigate nectar-robbing bees.
Thursday, July 22, 1999
Evironmental News Network
   Danger may loom for the lovely, red, trumpet-shaped blossoms of the scarlet
gilia, a Rocky Mountain plant, according to researchers from the University of
Vermont. They say the flower's nectar is in jeopardy because bumble bee
"thieves" have been preventing sprightly hummingbirds from pollinating the
gilia.
   Past studies have shown that nectar robbing may in fact have a positive
effect on the reproductive success of a plant. Some robbers can unknowingly
aid
in a plant's pollination when they brush up against floral reproductive
structures. In this study, published in the July issue of Ecology, researchers
Rebecca E. Irwin and Alison K. Brody wanted to know if nectar robbing was
detrimental to the scarlet gilia.
   To study the bee's effects on the gilia, the researchers first studied the
method by which the robber steals nectar from the plant's blossoms. They found
that the bee uses its spiky, toothed mouth parts to chew a hole through the
side of the corolla, the petals that surround the inner parts of the flower.
The bee then sucks the nectar out of this hole through a long, snout-like
proboscis.
   While this method provides ample nectar for the bee, there is none left for
other winged creatures, such as the hummingbirds that migrate through the
region.
   The bee thieves also fail to pollinate the plant, a process that would
likely occur after a visit from a hummingbird. Pollination in the gilia occurs
only through interplant pollen transfer. For successful pollination to occur,
the pollen of one plant must be transferred to the stigma of another, where it
can fertilize the ovule and form seeds.
   Nectar robbing, therefore, has the potential to be highly damaging to the
plant's reproductive success, the researchers say. Since individual gilia
plants bloom only once, estimates of lifetime reproductive success can be
measured in a single season.
   The researchers measured the rate of pollen transfer between the scarlet
gilia plants by placing dye particles on flowers to imitate pollen. The number
of dye particles deposited on flowers was compared in plants with low and high
robbing rates. This was associated with the amount of pollen transferred by
pollinators.
   They found that highly-robbed flowers donated and received fewer dye
particles, indicating that less pollen transfer was occurring among those
plants which were visited often by nectar robbers.
   "The most probable explanation for the reduced fitness of nectar-robbed
scarlet gilia is that these plants attract less pollinators," said Irwin.
"Hummingbirds tend to avoid plants that are highly robbed, and visit less
flowers on those plants. Our study shows that nectar-robbing does decrease
reproductive success in the scarlet gilia, further research will elucidate the
effect of floral larceny on the evolution of floral traits."