Tag Archives: pollination

Welcoming native bees

I gave a Zoom lecture last night on why people should care about native bees, and promised the audience (friends of Belmont Hills Library, in Bala Cynwyd, PA) that I’d share some links, photographs, and answers to some of the questions at the end. If you have any lingering questions or thoughts, please don’t hesitate to contact me. Good luck attracting bees, and thanks again for the invitation.

My blog posts I referenced

Links of interest

Articles

Bee books

Answers to questions

  • Good native ground cover to replace English ivy? A: golden groundsel (Packera aurea).
  • Honey from any native bees? A: yes, from stingless bees. I have a few photographs from Costa Rica and Mexico. It’s more liquidy than European honey bee honey.
  • Are yellow jackets wasps or bees? A: wasps
  • How deep do ground-nesting bees dig? A: I looked up the record and in some species the tunnels can extend down 10 feet or more. But 12 to 18″ is more typical.
  • Do figs actually eat wasps? A: Figs in the wild are pollinated by wasps, but as I mentioned, the varieties we grow in the United States don’t require pollination, so the crunch is not due to wasps within. Fig and biology fans should read Gods, Wasps, and Stranglers: the Secret History and Redemptive Future of Fig Trees.
  • Is it worth keeping hostas in pots for leafcutter bees A: It is never worth keeping hostas alive for any reason. But leafcutter bees will use them, I’ve read.

Photographs I showed or meant to show

For more photographs of bees (and wasps), my full collection is on SmugMug.

#BeeBest

Miniature mason bee hotel

Just a pic of the latest mason bee hotel I made, this one for my sister. It’s heavy, but designed to slide into a medium USPS flat rate box. Sides are cedar, top is exterior-grade plywood sprayed with a preservative. Blocks are made from old dimensional lumber (circa 1906), with 5/16″ holes that are 6″ deep. Block unit is removable so that pupae can be protected from parasites, birds, and weather once all the holes are sealed. Next spring, new blocks will be popped in while the current blocks are set outside (inside a box that has a small escape hole) to release their occupants.

Bees are going to begin their activities in the next couple of weeks, so build yours ASAP or buy online. Situate the hotel near a window so you have something to watch while you sip coffee in the morning. They make great gifts, especially if recipient has a garden, fruit trees, or blueberries.

For details and links on building mason bee houses, please see my earlier post. If you already have one and own a nice camera, please post photographs of residents on iNaturalist, then add to my Bee and Wasp Hotels project. There are multiple species of mason bees, plus you’ll get leafcutter bees, and nest-provisioning wasps. All of these residents will, of course, attract parasites such as cuckoo wasps.

For an excellent introduction to mason bees, I highly recommend “Mason bees: fun and friendly” and “It’s mason bee season!” by Marten Edwards (who was in my chemistry class at Reed College).

Augochlora pura foraging for pollen on maize

Last week I found hundreds of pure green Augochlora (Augochlora pura) foraging for pollen on Zea mays at Stroud Preserve in West Chester, Pennsylvania. Here’s my favorite capture, which shows a bee cutting open an anther with her mandibles.

Augochlora pura foraging for pollen on corn (Zea mays)

I was a tad surprised to see a wind-pollinated plant so mobbed with bees, but a later search of the internet suggested I shouldn’t have been. Even honey bees forage on corn, though the pollen is apparently not as desirable as other sources (e.g., Höcherl et al. 2011). This is also the reason why spraying a cornfield with insecticides can easily cause problems for any bees (and pollen wasps) that collect pollen.

This next photographs shows a better view of the scopa (modified hairs that hold the electrostatically-charged pollen) on the legs and abdomen. It also shows off how incredibly large corn pollen is (perhaps 85 microns, per some estimates, which is huge). Wind-pollinated plants with large pollen are odd.

Augochlora pura scopa with corn pollen

The final photograph shows some pollen grains set in motion by the foraging bee. The odd look (line segments with bright dot in middle) are presumably caused by the flash freezing the fast-moving grains only in the middle of the exposure (1/200 of a second). I’m not exactly sure why the grains are bright. It could be because they are strongly backlit by sun, but it could be something related to how pollen grain exines bend light (they can cause a pollen corona on allergy-alert days). Someday it might be fun to get a rear-curtain flash configured to better capture such motion.

Pure Green Augochlora (Augochlora pura) collecting pollen from corn