nebraska | The Prairie Ecologist

A guest post by Anne Stine, one our Hubbard Fellows. All photos by Anne.

I adore hummingbirds, and I sometimes bemoan their rarity in my new home here on the Platte. I grew up thinking they were better than fairies- they are cute, ferocious, and they migrate long distances despite their small size. While hummingbirds themselves are scarce in this part of the country, “hummingbird moths” are abundant. Hummingbird moths are so-named because they hover and fly like hummingbirds, sip nectar, and are approximately the same size as hummingbirds. I never noticed hummingbird moths growing up, so since moving here it is as if hummingbirds dropped out of the system and were replaced by enormous insect imposters.

Hummingbird moths, or sphinx moths, are large, furry, and active in the day. Their caterpillars are called “hornworms” because they have what looks to be a long horn extending off their rumps. Most of these larvae have multiple potential food sources. Around here, likely food plants include four o’clocks, wild grapes, elms, and evening primroses¹. While some species of hornworms eat crops like tobacco and tomatoes, they are infrequently a pest requiring treatment. In fact, with their propensity to eat undesirables like Siberian elms and weedy species like four o’clocks and evening primrose, one could even characterize them as beneficial.

Hornworm larvae, possibly of white-lined sphinx moth?

There are two broods of sphinx moth annually, one emerging in spring and another in fall². Hornworms pupate in shallow excavations in loose soil¹. In the past few weeks I’ve encountered hornworms attempting to dig their burrows in our driveway at the crew house. Of the adults, I see the white-lined sphinx moth (Hyles lineata) most frequently. Twice they have been attracted to my brightly colored clothing (pink shirt, orange shirt). The moths hovered around investigating me for nectar reserves. I’ve seen them feed on a variety of flowers, so they must not be too picky.

Hummingbird moths are an intriguing substitute for hummingbirds. Hummingbird moths are widely distributed across North America, so it would be interesting to learn if their role as pollinators takes on a greater importance in areas where hummingbirds are absent.

White-lined sphinx moth, front view.

White-lined sphinx moth, side view, proboscis unrolling.

White-lined sphinx moth, back.

¹ http://www.butterfliesandmoths.org/species/Hyles-lineata

² http://puyallup.wsu.edu/plantclinic/resources/pdf/pls48sphinxmoths.pdf

I found this robber fly perched in the prairie early Monday morning. Although it was fairly breezy, the light was good enough to attempt a photo. I’m glad I decided to give it a try.

Robber fly. The Nature Conservancy’s Platte River Prairies, Nebraska. You can always click photos to see a sharper version.

Ten years ago, I wouldn’t have even considered attempting this photo. When I was shooting with slow speed slide film, I loved the saturated color of Fuji Velvia, but every time I clicked the shutter it cost me about 34 cents in film/processing. That kind of cost made me pretty leery of trying to photograph something like a flower that was blowing around in the wind. A shot that came back blurry because the subject was moving too fast cost me just as much as a nice sharp image, so I couldn’t afford to “miss” very many times. I would often take 3-4 versions of the same shot to make sure I got the exposure and focus correct, but even that was costing me about a dollar per good image.

This week, I photographed the above robber fly for about 5 minutes. Within that time, I took 162 images. The vast majority of those were blurry because the wind was swinging the fly and its perch so much I couldn’t focus and shoot fast enough to keep up. I ended up with only a few sharp images in three different compositions. Ten years ago, taking 162 photos would have meant about four and a half rolls of slide film and would have cost me about $44. This week, it just meant I had to sort through 162 images to find the good ones – something that took just a few minutes.

Digital photography can sometimes make me a little lazy because it’s tempting to let some of the fundamentals of exposure and composition slide and try to fix things later with digital processing and cropping (though I usually don’t do much of that, and there’s still no substitute for getting it right in the field). On the other hand, digital photography allows me to take risks that would have been unthinkable (or at least really expensive) in the old days. Blurry photos don’t cost a thing now, and can often be deleted in the field. Just as important, I can make sure I’ve got the shot I want before I leave, instead of discovering it days later when my slides come back from being processed. Overall, it’s a pretty good time to be a photographer.

Just for fun, here are some of the other images from the brief photo session with the robber fly.

This one ended up relatively sharp…

…but I had 30 more that looked like this.

This one (like many others) was pretty fuzzy…

…but this one isn’t too bad.

The Prairie Ecologist

Essays, photos, and discussion about prairie ecology, restoration, and management

Tag Archives: nebraska

Hubbard Fellowship Blog – Hummingbird Moths

Photo of the Week – October 3, 2013