These are the dog days of summer and it’s still plenty hot here on the Front Range, but there are starting to be signs that Autumn isn’t too far away.
The days are already getting shorter and I’ve seen flocks of Canada geese and grackles hitting the skies. In the mountains, the hummingbirds are loading up on nectar and insects to get ready for their own southern migrations.
Broad-tailed hummingbirds are the most common hummingbird in Colorado in the summer and last weekend in Estes Park they were zipping along everywhere! The weekend before that, I was in Colorado Springs visiting the Starsmore Discovery Center and they were there too, but some of those hummers looked a little strange…
In fact, some of those “hummingbirds” weren’t birds at all! Sometimes known as a “hummingbird moth” or “hawk moth,” the white-lined sphinx moth (Hyles lineata) is a large, fuzzy brown and orange striped moth with a pink patch on the hind wing that is common across much of North America, though it is particularly abundant in desert regions. Unlike a lot of moths, the white-lined sphinx may be just as active during the day as at night and its rapid wing beats allow it to hover just like a hummingbird.
The white-lined sphinx isn’t a particularly picky eater. As an adult, it’ll sip nectar from native flowers like penstemon and columbine, as well as flowers you might have growing in your backyard garden like petunia and lilac. The larval form is fond of crops like tomatoes and grapes, which can be a problem in farming areas, as well as evening primrose, which is a host of the caterpillar. Where that flower grows in abundance, the caterpillar is also likely to appear in great numbers. This past spring at Pawnee National Grassland the road was covered with the little green and black critters.
In warmer areas, there may be 2 broods of caterpillar. When they’re ready to pupate, they disappear underground and emerge again as adult moths. Not long after emerging, the female moth will release pheromones to attract a mate. The resulting eggs can number up to 1,000. Like many insects, after breeding, the adult moths will die and the life cycle will begin all over again.
Keep an eye out for these colorful and fascinating moths when you’re on your next hike.