A case of moth envy: hummingbird moths of our area

by Renée De Vry

A hot early-July afternoon spent at my favorite nursery, trying to decide what plants to adopt. I had come in to pick up more Plantain-leaved Pussytoes (Antennaria plantaginifolia) as several desperate American Lady butterflies (Vanessa virginiensis) had laid eggs on my three little plants and the caterpillars were munching faster than they could grow. My wagon held the last six plants in stock, but I was wandering, trying to figure out what else I could sneak past my partner’s disapproving eye.

I had earlier walked past a young woman, sporting that awestruck look so common to people who notice a flock of Hummingbird Clearwing moths (Hemaris thysbe) nectaring on the Butterfly Bush (Buddleia davidii) on display. I have felt that fluttery urge to reach out and hug those cuties myself. Reaching the end of the row, I turned around and came back down the aisle to catch her square in the act of trying to catch a moth for herself.

“Stop! That’s no way to get these guys into your garden,” I said. She told me to mind my own business as nobody owns these moths.

“That may be,” I said, “but hummingbird moths are like people with obsessive compulsive disorder. They establish strong repetitive routines that you can practically set your watch by. They will just fly away from your garden if you try to move them, creating moth trauma for nothing, but I can show you a way to establish your own little flock if conditions are right in your garden.”

She pulled out her phone and proceeded to show me pictures of her Kanata garden. She had Monarda sp., Verbena sp., several clumps of Phlox and two Butterfly Bushes. She even had an Ohio Buckeye (Aesculus glabra) in her front yard. Her backyard was next to a wide open field in semi-rural conditions with Dames Rocket (Hesperis matronalis) among the weeds and several Mock Orange shrubs (Philadelphus sp.) along the fence line. All was perfect – except she had no caterpillar food plants.

The right way to bring pollinators home

“The key,” I explained, “is to raise babies in your yard and they will come back every year. Let’s look at food plants, as these adults are likely laying eggs somewhere close by.”

So off we went to look at viburnums. If the pots had been sitting on white plastic instead of black weed cloth, we could have homed in by looking for poop under the plants. Instead, we carefully looked under the leaves of each plant but found no round green eggs or small lime green caterpillars. Then we headed for the Snowberries (Symphoricarpos alba) where we found one egg.

We popped that plant onto her cart then headed for Trumpet Honeysuckle (Lonicera sempervirens) vines and native Northern Bush-honeysuckle (Diervilla lonicera). We hit the jackpot with five little caterpillars on the vines. So she chose three big plants, and we moved the caterpillars gently into a cup for the ride home. She promised to plant her shrub and vines as soon as possible and keep them well watered. She also planned to come back to pick up some High Bush Cranberry (Viburnum trilobum) as an option for next year’s caterpillars.

I wished her luck and went back to wondering who to adopt? – the fat healthy Culver’s Root (Veronicastrum virginicum) in the corner, the overwatered and sad but salvageable Prairie Smoke (Geum triflorum) in full sun, or those cheerful Blanket Flowers (Gaillardia aristata) all ramped up on too much fertilizer in the outer row.

About clearwings

We have five Hawk Clearwing moth species in Canada, and they can be tricky to tell apart on the wing. There is quite a range of coloration within each species as adults. They hover and hum while nectaring and can easily be mistaken for mini-hummingbirds or big bumble bees. They never land like a bee does while nectaring but can sometimes be seen tasting the flower sweetness by tapping the flowers with their front feet. (Watch one in action.)

In Ottawa, the Hummingbird Clearwing is the most common, but I have seen the Snowberry Clearwing (H. diffinis) as well. It tends to be more yellowish and can also be called the Bumble Bee Clearwing.

Diervilla Clearwing moths (H. aethra), look just like Snowberry Clearwings, but their caterpillars appear to feed exclusively on native Northern Bush-honeysuckle leaves. They also have different coloured feet: H. diffinis caterpillars have black feet and H. aethra caterpillars have red feet.

Slender Clearwing (H. gracilis) is found in acid soil areas covered by Blueberries (Vaccinium sp.) in much of eastern Canada, but the Rocky Mountain Clearwing (H. thetis) can only be found in the Western provinces.

To attract these lovely moths, plant both caterpillar forage plus a full season of deep tubular flowers in a sunny area protected from strong winds.

More about clearwings

• Schmidt BC. Cryptic species among bumblebee mimics: an unrecognized Hemaris hawkmoth (Ledpdiptera: Sphingidae) in eastern North America. Zootaxa 2016; 4399(1): 32-48. This article by a local researcher and leading expert on Hemaris spp. includes correct locality maps for several species. Also, many excellent photos of both adults and caterpillars.
• BugGuide: Hemaris
• Butterflies and Moths of North America: Hummingbird Clearwing (Hemaris thysbe)

This video of a hummingbird moth nectaring on Common Milkweed (Asclepius syriaca) was shot by C70drvr in Ottawa in 2011. It gives a good idea of the size of these large moths and shows how they might easily be mistaken for a hummingbird. Note: as pointed out by B. Smith, the moth in this video is a Nessus Sphinx (Amphion floridensis), also a member of the sphinx moth family.

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Renée De Vry has a wealth of experience growing native plants and is a keen observer of the creatures that use them. She managed the Meditation Garden at the Unitarian Church on Cleary for 20 years.

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