Re: [beemonitoring] Hawaiian Bees (Hylaeus) and theri pollen [1 Attachment]
- Dear Fanciers of Hylaeus:Dr. Gottleib is entirely correct. Stop stereotyping Hylaeus species as pollen thieves (or selfish gluttons) because they swallow pollen. Flower-visiting beetles and syrphid flies do precisely the same thing and yet they pollinate diverse guilds of flowering plants in certain parts of the world. Identifying pollen based on molecules in the bee's crop is a wonderful and exciting tool but you can acquire much the same evidence by catching the bee, euthanizing it and then washing pollen off the body with a little ethyl acetate. Once the EA evaporates you stain with Calberla's fluid and identify the grains under the cover slip. My techniques are described in Dafni's big book of pollination techniques.How do pollen grains cling to a Hylaeus bee? Probably the same way they stick to other insects or birds that don't provision their offspring with pollen. They're not hairless, you know. Remember the power of static cling and also the adhesive qualities of pollenkitt (tapetal derived lipids) on the pollen wall. Don't believe me. Euthanize a Hylaeus on a flower, spatter coat it and place it under the SEM. You will be amazed.Hylaeus species get little respect here in North America because their are plainly outnumbered by other insect species in sheer number and diversity. Please look at the big Table in the attached. Physaria filiformis received Hylaeus spp. and some carried the pollen of the host flower but these bees were completely outnumbered and outclassed by species in other families.Now I wish I published some information collected while completing my PhD back in 1981. Hyleoides concinna collected pollen of Amyema preisii (Loranthaceae). It's body was large enough to contact the stigma while it foraged but, like Phormium, the major pollinators were birds (meliphagids). See Chapter 5 in "The Biology of Mistletoes (1983, Academic Press Australia).Remember, Calberlas's fluid is out friend.PeterOn Thu, Feb 9, 2012 at 1:02 AM, <ariellag@...> wrote:[Attachment(s) from ariellag@... included below]
If I may speak in behalf of at least some Hylaeus sp.,
They are doing a pretty good job pollinating Zygophyllum dumosum in
the deserts of Israel.
I'm doing single visit pollination experiments as part of my PhD work
in the Israeli Rift Valley.
Hylaeus are part of the local bee community.
Yes, they collect pollen in their crop, they are small sized and have
a pathetic pubescence.
Despite that, they were slightly better pollinators than Honey bees
and Halictus and almost as good as Hoplitis to the local plant
Sometimes all you need for successful pollination are a few leftover
pollen grains round your mouth and legs (and just the right size and
behavior to make contact with the stigma. Photo attached).
Tel Aviv University