leafcutting bees

Cosmos: a multipurpose bee flower

Leafcutter-she-bee

I planted two different types of pollinator seed mixes this year, not for the bees to tear up, but to provide pollen and nectar. Both the mixes contained cosmos varieties that grew tall and strong.

At first, I noticed only bumble bees and honey bees nectaring on the blooms, but almost immediately I saw big arcs cut out of the petals. “Who’s that?” I thought, ready to blame some other type of creature. But then I began seeing leafcutting bees—at least three different species—all over the flowers. They are shy, so you have to sneak up on them and pretend you don’t have a camera.

It just so happens that capturing a leafcutting bee cutting a leaf was one of my photographic goals for the year. But in spite of the ragged flowers, I cannot find one bee in the act. Lots of males drink the nectar, and lots of females collect the pollen, but so far they won’t carve a petal in front of me.

So if you’re taking notes on these things, you can try planting cosmos as a leafcutting bee attractant. I’m putting it on my list for next year. Till now, I never thought of cosmos as anything but a nectar and pollen plant, but who knew?

Rusty
HoneyBeeSuite

Cosmos-after-leafcutters

This cosmos bloom now has scalloped edges, thanks to the leafcutting bees. © Rusty Burlew.

Leafcutter-he-bee

This is a he bee and not the one doing the damage. Note the fringed forelegs and white face—both are common on male leafcutting bees. © Rusty Burlew.

Leafcutter-she-bee

This is a she bee (on physalia) as evidenced by the hairy scopa on her abdomen. Leafcutting bees often hold their wings out to the side instead of folded over their backs. They also hold their abdomens high, probably to keep the pollen from rubbing off. © Rusty Burlew.

18 Comments

  • Hey Rusty,
    So that’s what it’s called (lol) Cosmos,
    Thank you for clarifying that!!!! And believe
    it or not, a praying mantis is onto it as well,
    she knew before I did, that’s her new food pantry!!
    Tonybees

  • Hey Rusty,
    I have those plants and I felt like an idiot when
    Mike and the film crew asked, I bunched them
    together, “The bees will be all over the Wildflowers over there in a bit” thanks for clarifying! Cosmos!!!
    Tony

  • Rusty – LOL!
    Mental image, you, strolling about, murmuring “Oh look! Leafcutting bees! and me without my camera!” All I can think of is Winnie the Pooh, pretending to be a cloud in order to steal some honey, and Christopher Robin marching up and down with an umbrella, saying “Tut-tut! It looks like rain.”
    My bees are foraging burdock, smartweed, chicory, black-eyed susan and tickseed coreopsis. Wonder how “WEED HONEY” would look on a label?
    Thanks for the chuckle.
    Nan

  • Hello everyone,
    Cosmos was in my Tx Wildflower seed mixture I planted fall 2014, but didn’t reach its potential because of flooding rains this past spring. ( I am in South Texas) I then planted cosmos seeds in raised beds in June, and these guys grew to enormous +6ft hight but flowered in August and it is December and they are still ginormous with hundreds of blossoms. I was looking for info on whether it produced nectar because I saw Hummers all over it in migration. Every flying insect from flies to monarchs and its lookalikes to many kinds of bees/wasps, some I have never seen before. I am still stoked over the success of this plant.
    Wildflower honey is abundant down here. The bees and butterflies are all over my Gregs Mist flower,which is also still blooming like crazy:) this was my first year planting pollinators gardens. I wanted to help the Monarchs.there are still monarchs and queens and hundreds of bees on these flowers. I wish I could send you a pic. (I also plant milkweed ) I am in the city but coastal zone 9 Thanks for letting me tell my story. I must go out and see if the bees are harvesting petals 🙂

  • I planted the Sulphur Cosmos (yellow/orange variety) three years ago. My bees will go to them, mostly during a dearth, but they will work them. The Sulphur Cosmos flower is self-cleaning, reseeds itself and doesn’t require stratification. So, your can reseed, or it will self-seed until frost kills them. The seeds are cheap and one package from the Dollar General is all you will need to buy, ever.

    My bees never, ever even lit on the pink ones, which have foliage and flowers that die off ugly. The pinks don’t reseed easily, either.

    I don’t know anything about what their nutritional value is to the bees. If you want something your honeybees love that is super easy, a bit ugly and that blooms from May to frost, try Sacred Basil. Plant once and done!

  • I live on the island of Oahu, state of Hawaii. Some 15 years ago I sowed and nurtured a smallish bed of cosmos. The resulting blooms were pretty and hardy, and I noted that the vast majority were solid pink-purple (I assumed the dominant color) with an occasional pure white. Slowly, slowly, I began to see more and more, and now an infinite variety, of patterns, and now it is my constant pleasure to look for and harvest the seeds of new-patterned cosmos. I’ve assumed that I am the beneficiary of honey-bee cross-pollination of my favorite flower…one that I can continuously rotate and have confidence of growing success year-round. I’m curious: why has this phenomenon of cross-pollination not been discussed in this article and the comments? (P.s. I’ve never had a cosmos plant/flower where a bee has “cut arcs out of the petals” and I would not be pleased if that were to happen to me. I do of course have problems with slugs, aphids, white flies, tiny insects that glom onto, hollow out and ruin the seeds (if I’m not careful with the harvesting, storing process), birds–mainly doves–that lust to scratch-and-steal-and-feast-on my seeds just after planting, other small birds/finches that snatch-and-fly-off with mature seeds at the end of the growing cycle, wind, rain if over-abundant, and other irritants of nature. (I cut and display EVERY DAY a small/stylish bouquet of cosmos and place it next to my beloved wife’s urn…each bouquet can last 3-4 days, or sometimes less due to factor(s) I haven’t yet come to good grips with.)

    • Robert,

      If were fortunate enough to see leaf-cutter bees or petal-cutter bees cut and remove those circles, you would be enchanted. It is the coolest thing in the world. And if you got to see one of their nests, all patchworked together with different colored petals, you would love it even more. I’m sure you wife would have approved of such creative and industrious creatures.

  • Your last picture, with the “she bee” on a physalia, is the name of that bee actually a “she bee”? As you can imagine, googling that leads to an endless succession of blogs and other things trying to sell me something but nothing helpful. Pretty sure I had one on some Lupine last summer (I’m in Winnipeg, Manitoba, just north of North Dakota), now trying to ID it. If it turns out to be a leafcutter, then I’ll be proud to say I have a picture!

    • James,

      I have a somewhat lame sense of humor that comes from a love affair with words. A “she bee” is just a female bee just as a “he bee” is a male bee. All of which gives me the hebee shebees.

      This has nothing to do with anyone’s lack of intellect except for my own. Sorry to lead you astray.

      If you send me your photo, I will take a stab at an ID for you.

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