Pollinator of the Month – CO Soldier Beetle

September 7, 2022

Written by Amy Yarger, Butterfly Pavilion Horticulture Director

Most of us have seen the black and white footage of teenage fans screaming for the Beatles, but there are very few people who are fans of U beetles, even though these insects are so important to our ecosystems. What would it take for people to call themselves “Beetles Fans”? I’m here to make a case for one of our most common and charismatic pollinating beetles, the Colorado soldier beetle.

Colorado soldier beetles are about 1 centimeter long, with a narrow body and long, thread-like antennae. A distinguishing characteristic of most beetles is that their 2nd pair of wings, instead of helping with flight, has become protective armor called an “elytra”. The elytra of Colorado soldier beetles is softer compared to other beetles, so another common name for these insects is “leatherwings”. Colorado soldier beetles are hard to miss with bold black and golden orange markings, which may vary according to body size and whether the beetle is male or female.

These bright colors serve as a warning to spiders and other potential predators. Soldier beetles secrete irritating chemicals that make them unpalatable. Bright colors advertise the danger, like a stop sign or caution tape. But that’s about the only sort of danger associated with these insects; they prefer to “make love, not war”. If you find one soldier beetle, you will probably find at least one more, usually attached in the act of mating. Pollen-eating beetles are usually called “mess and soil” pollinators for the slight damage they inflict on male parts of flowering plants, but I call Colorado soldier beetles “date and mate” pollinators, because they don’t let reproduction get in the way of a good meal. Perhaps it’s the insect equivalent of “dinner and a movie”. Anyway, the plants need them for their own reproduction, so who can judge?

Once they’ve mated, the female soldier beetle lays eggs on the soil surface, under sheltering debris. The shy grubs hatch soon after and eat small insects until the cold season. Eventually, they will pupate in the soil, then emerge as adults in mid to late summer, just in time for the bloom season of their favorite plants, such as goldenrod and rabbitbrush.

This species of soldier beetle is found primarily in grasslands on the plains; there are other species that are more common at higher elevations. As more people plant native plant gardens along the Front Range, these beetles are able to live peaceably among us in urban areas, as the true ambassadors of “flower power”. If you’d like to see more Colorado soldier beetles in your own landscape, you can plant more late-season blooming plants, such as dwarf rabbitbrush. Avoiding landscaping fabric and leaving last year’s debris in your garden also provides the perfect conditions for soldier beetle larvae, allowing the generations to continue. Then you too can join the Beetle Fan Club and appreciate these unsung local pollinators!

Want to learn more about pollinators and how to help them? Contact Butterfly Pavilion’s horticulture department at habitat@butterflies.org!

If you see this pollinator or others around Baseline, take a picture and upload it to Baseline’s iNaturalist page. By doing so, you can be a citizen scientist and help track the diversity and volume of pollinators at Baseline.