We saw these same insects gathered in ones or twos on a few other blossoms (see the other photo), but we only saw two blossoms, both on the same plant, with this number of the insect.
May 22, 2015, Edgewood County Park and Natural Preserve, San Mateo County, CA, USA
CC By-NC-SA 2015 Laurie Alexander
One or two flowers on each branch of a stem open in the late afternoon. Today was overcast, windy, cool (60's). Did that affect the time the blossoms opened? Didn't seem to affect the number that opened.
Four chambered fruit, opened, with one seed left.
Airplane, complete with winglets! About 1" across. Kudos to Marisa for this find.
Found a wooden fence along the creek. ID provided by Chris Mallory from images I posted to Bug Guide. This is an introduced beetle species used as a biocontrol agent.
Photo didn't turn out very well, but the trunk was smooth and reddish-orange.
In the trail.