Durango Nature Studies’ educators Mike Bienkowski and Kiley Smith, along with an amazing team of volunteer naturalists, wrapped up the final school field trips at the Durango Nature Center at the end of May.
It was quite the year for our school-based programs, concluding with a relatively soggy spring season where we hosted nearly 1,000 students from 13 schools throughout the region over a seven-week period.
Kindergartners and first graders comprised the majority of our springtime visitors, but we hosted older students, too. While we have lessons for each grade that meet science standards, part of the magic of these field trips is giving students free rein to their curiosity. When it comes to younger students, it doesn’t take much to pique that curiosity.
As temperatures warmed in early May, our young students witnessed the emergence of one of Colorado’s largest insects in the “hemiptera” order – the cicada. Some sources refer to hemiptera as “true bugs,” and include some 50,000 to 80,000 species, including aphids, leafhoppers and shield bugs. Their distinguishing characteristic is mouth-sucking parts. Some insects in this order can cause significant damage, but the cicada is harmless.
According to Colorado State University Cooperative Extension, Colorado has approximately 29 different types of cicada. I’m not sure exactly which species inhabit the Nature Center, but I invite any entomologist to visit and help identify them. I find them to be a fascinating insect, and many children attending field trips this spring were mesmerized seeing their exoskeletons everywhere.
Females lay eggs into the stems of plants, and the hatching nymphs drop to the ground and promptly burrow into the soil where they will feed on the fluids from plants and slowly develop over a number of years. The final action for a nymph is to dig to the surface and emerge from its exoskeleton as an adult, leaving an alien-like shell clinging to all sorts of surfaces. The adults will live for four to six weeks, laying eggs before dying. Cicadas are difficult to spot but often heard, as males sing to attract females. Most cicadas have a structure called a “tymbal” on their abdomen, and the “singing” is really clicking that resonates through their body.
In Colorado, most cicada species spend three to five years below ground before emerging above ground and molting. Some cicadas have 13- and 17-year life cycles. Parts of Pennsylvania, West Virginia and eastern Ohio are currently seeing the emergence of a 17-year species, affectionately known as Brood VIII.
The mathematically-inclined person might quickly pick up on cicadas’ tendency to have population cycles that are prime numbers. A quick online search reveals the most common theory to this has to do with successful evolutionary theory to avoid the population cycles of their primary predators.
The species that emerge every 13 or 17 years are called “magicicada.” When their time comes, the magicicada emerge in such swarms that the noise can be deafening during their short adulthood, and then, it can be difficult to avoid the bugs after they’ve died. Fortunately, we don’t have quite the onslaught of these insects at the Nature Center, but there is ample evidence of their existence, much to the intrigue of many of our May visitors.
While the influx of cicadas has now ended, our summer campers will have plenty of other insects and other animals to learn about over the next couple of months. If you’re curious, we welcome you to visit the Nature Center on Saturdays when it’s open to the public.