Common and abundant, the white-lined sphinx moth is busy at flowers when butterflies go to sleep for the night. PHOTO (c) MATT BARTMANN. Used with permission.
When the sun goes down and the mosquitoes come out, most of us retreat indoors. Time to kick back with TV and Facebook and whatever else keeps us busy ‘til bedtime.
If you put down that remote for a minute, though, and step outside, you’ll find a whole other world of nighttime critters out and about.
The lightning bugs east of the Rocky Mountains—nope, we don’t have them here at our place—are wonderful and hard to miss, and I hear they’ve been spectacular this year.
But as my favorite TV commercials say, “Wait! There’s more!”
Start by checking your flowers for pollinators.
No, you won’t see bees or butterflies at night.
But you will see moths.
Sphinx moths. Moths that hover like hummingbirds. Moths with gorgeous colors on their hindwings. Moths with 4-inch-long tongues.
Well, not tongues, exactly—“proboscis” is the name for a moth or butterfly’s “drinking straw,” and these guys are tailor-made for certain flowers.
If you’ve ever seen what looks like a baby hummingbird hovering at your flowers in daytime, you’re already met one type of sphinx—the day-flying hummingbird sphinx moth, a species with clear, see-through wings that fools many folks into thinking it’s a hummingbird.
That hummingbird sphinx moth has cousins.
Cousins that come out at night.
And “hummingbird flowers,” those with a tubular shape or with spurs filled with nectar, are the same sort of blossoms these moths seek.
Ever wonder why some flowers open their furled buds late in the day or at night?
In our area, native white evening primroses are the night-bloomers—the perennial Oenothera caespitosa that grows in the crannies of cliffs, and the smaller, less showy—dare I say “scrawny”? 
—annual Oenothera albicaulis.
As soon as the petals unfurl, they release a heady burst of fragrance. And that’s what calls in the moths, just as flowers that are fragrant in daytime call in butterflies.
The white-lined sphinx is the most abundant nighttime sphinx moth. Often, it works a double shift, out and about during the day as well as at dusk or dark.
“I saw a hummingbird at night!”
Um, sorry, no, you didn’t.
If you see a “hummingbird” at your flowers after dusk, you can bet your bottom dollar it’s a sphinx moth.
Sphinx moths are big guys, with unusual wings that can rotate at the base, so they can hover just like a hummingbird.
No other moths can reach the nectar down in the tubular base of a “hummingbird flower.”
But sphinx moths have extra-long “tongues.” And their 3- to 4-inch-wide wings will be easy to spot against the pure white flowers, even if, somehow, you didn’t happen to notice the flowers moving from the wind of their rapidly beating wings.
Check out that proboscis! Sphinx moth “tongues” are incredibly long, so they can dip deep into tubular or spurred flowers. Notice, too, that this one has its wings rotated, so it can hover at the flower, just like a hummingbird. PHOTO (c) 2014 MATT BARTMANN. Used with permission.
All you’ll see is a blur as the moth hovers and moves from flower to flower, dipping its proboscis in deep to slurp up the nectar.
No white evening primroses?
No problem. Sphinx moths visit lots of different kinds of flowers.
We’ve seen them hovering just above the ground to take nectar from the low-growing native yellow corydalis (Corydalis aurea), one of the earliest spring bloomers, as well as the longest bloomer—its small tubular flowers keep going well into summer.
Maybe you’ve noticed how some flowers smell better at night. That’s a moth-enticing trick, too. Like fragrant flowers that bloom during the day, their scent is meant to carry on the night air to attract moths.
And our friends the sphinx moths will come hither.
Having done many a sniff test over the years at nurseries and garden centers in order to pick the most fragrant flowers, I’ve noticed something else: It’s the palest colors or the white varieties of many plants that smell the best.
Bet you can already guess why. Yep. Moths.
White and pale flowers show up best after sundown, so that’s extra incentive for moths to pollinate them—not only do they smell great, they’re easy to find in the dark.
My favorite flower for attracting sphinx moths is our native blue columbine (Aquilegia caerulea).
Different species of columbines are shaped to appeal to different pollinators—some to hummingbirds, some to sphinx moths, some to bumblebees or other critters.
Our blue one depends on the white-lined sphinx for pollination.
Their circlet of white petals within those lovely blue spurs and sepals easily show the target to moths at night.
The breathtaking blue “petals” of the Rocky Mountain columbine are actually sepals. The true petals—in the center of the flower— are white, and they’re connected to the long spurs that hold the nectar. PHOTO (c) MATT BARTMANN. Used with permission.
Over the plant’s month or more of bloom, we’ve often had fun watching a white-lined sphinx circle the plant for a long time, dipping into one petal of a flower after another, then on to the next blossom on the plant.
It’s pollinating the flowers.
And the success of its work is immediately apparent, as soon as the seedpods form.
Columbine seedpods are cool, and instantly recognizable.
They look like a little cluster of fingers connected to the stem.
Each of those “fingers” is a chamber of the ovary, and each one is filled with seeds—if pollination is successful.
That fuzzy-looking yellow cluster in the middle of a columbine blossom?
Those are the pollen-laden anthers, the male parts of the flower.
If you look close, you can see the girls—the female pistils, sitting in the middle of the boys.
It’s a nifty arrangement, meant to guarantee pollination when the moth stirs the pollen grains as it’s feeding.
The pollen gloms onto the moth’s body—and then onto the next pistil it brushes against.
Believe it or not, columbines belong to the Buttercup Family (Ranunculaceae), along with their relatives monkshood (Aconitum spp.), meadow rue (Thalictrum spp.), larkspur and delphiniums (Delphinium spp.), clematis (Clematis spp.), anemones (Anemone and other species), baneberry (Actaea spp.), and good ol’ buttercups (Ranunculus spp.).
Why are all these flowers that look so different grouped together?
Because of their reproductive parts.
Most flowers—of other families—have only one pistil.
All of the members of the Buttercup Family, from gleaming yellow buttercups to the unusually shaped columbine flower, have multiple pistils. (You’ll need a microscope or magnifying glass to see the other fine points that taxonomists use to classify them into this family.)
These relatives also share one other important characteristic: They’re all poisonous, thanks to an acrid glycoside called protoanemonin. Some, more so than others.
I used to think that a columbine flower had 5 pistils, because of the five petals of the flower.
But apparently that’s not the case.
Many of the seedpods on our plant have 5 fingers. But some have 6 or 7, even 8. And some have only 3 or 4.
All of the flowers on this columbine plant had 5 petals. But the number of “fingers” in each seedpod varies, with some having as many as 8.
Guess I’m going to have to wait ’til next year to count pistils and find out what’s going on.
In the meantime, I’m keeping an eagle eye on the seedpods, so I can collect them when they’re ripe and shake out the seeds in other parts of the garden.
Summer is peak time for sphinx moths, both the day-flying clear-winged species, and the night flyers.
And you won’t have to be much of a night owl to get a gander at sphinx moths in your garden. Though they feast for hours, they take to the wing at dusk, starting their foraging soon after the sun goes down.
© 2014, Sally Roth. All rights reserved. This article is the property of Native Plants and Wildlife Gardens. We have received many requests to reprint our work. Our policy is that you are free to use a short excerpt which must give proper credit to the author, and must include a link back to the original post on our site. Please use the contact form above if you have any questions.
