Roger,

It's possible that what you're seeing are male Eastern Carpenter Bees
(Xylocopa virginica).  They look very much like bumblebees but their
behavior is as you describe, hovering for minutes at a time in one area.  If
that's what you've got, then the proximity of the pre-flowering shrubs may
be just a coincidence; the males hover near sites where females may be
constructing nests by tunneling into wood -- are there any wooden
structures, woodpiles, etc., close to your rhododendrons?  Alternatively, if
you can get a good look at the bees, a good mark for male Eastern Carpenter
Bee is that its face is yellow, not black as on most bumblebee species.

This species came out early up here in n.w. Ohio also -- I've been seeing
them  in Oak Harbor the last couple of days.

I know this is off topic for the bird list, but people who spend time
outdoors (like birders who aren't under deadline pressure) are sometimes
alarmed by Eastern Carpenter Bees because they hang around in a threatening
way.  But they're mainly looking to chase away rivals, and the males
actually can't sting, so there's no need to be concerned about their
seemingly aggressive behavior.

Kenn Kaufman
Oak Harbor, OH

----- Original Message -----
From: "Roger Troutman" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, April 15, 2010 3:43 PM
Subject: [Ohio-birds] Bumblebees and rhododendrons - off topic


> Hello list,
>
> This thread is more of an insect topic so if you are entirely into birds
> only - just delete it.
>
> Speaking of early insects getting the nectar/pollen?
>
> The last couple of days with temps above 70, about a half dozen (at most
> at
> a time) bumblebees (assumed to be queens because of their large size) have
> been cruising and "keeping station" for several seconds over my rather
> large
> rhododendron bush(s) (about 10' x 25-30' in horizontal cross-section) that
> is covered with XXX buds (none showing any color).
>
> The bees never land but seem to just hover about 4" to a foot or so above
> the foliage.
>
> I have seen at least a half dozen at once but they are coming and going
> for
> several hours a day.  During mid-day there is almost always 1 or 2 bees
> present at any given time.
>
> They just seem to be checking out the plant and but then leave for an
> unknown period of time. However they must be coming around several times
> an
> hour as there can't be that many bumblebees in the vicinity. In any case
> the
> buds are not swelling much and are probably at least a week or more away
> from blooming
>
> Any idea what is attracting them?  Are the plants putting off some kind of
> odor? Leaf or bud shape? Past experience (I'm not sure the queens survive
> from one blooming
> period to another.?)  Instinct? Premonition?
>
> They seem to be coming from nowhere and are not seen working other flowers
> around although such blooms are far and few between except for daffodils.
>
> Any thoughts from readers with a hymenopteran bent, leaning, knowledge or
> interest?
>
> Roger Troutman
>
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