My longest trip this summer took me out to the Umpqua National forest in Oregon, which encompasses a section of the Cascade Range east of Roseburg. For the first couple days, it was so hot that wildlife was scarce. Undeterred by the heat, insects were abundant, buzzing alongside our car from flower to flower.
One of the most striking insects was the cardinal meadowhawk (Sympetrum illotum), found in abundance in a shady meadow by Toketee Lake. After landing, they tilted their bodies until it looked like they were performing a handstand. This ’obelisk posture’ helps the cold-blooded animals regulate their body in hot conditions (1). By pointing their bodies at the sun, they minimize sun exposure, which helps them stay cool. (If you choose to open the linked article, the dragonflies I observed were doing posture A from Figure 1).
Another distinctive dragonfly was the eight-spotted skimmer (Libellula forensis), named for the dark spots on their wings. The species was found sitting in shrubs on the edge of a shady meadow. Common whitetail (Plathemis lydia), with a similar black and white color scheme but distinctive white body, swarmed alongside a small reservoir. Exuvias, the leftover shells from their final molting stage were also found in the sedges along the shore (2).
We also came across several cicadas, one of which we found perched on a willow stick next to a series of incisions. As part of completing their life cycle, cicadas insert their fertilized eggs into cavities in willow branches, where the eggs develop and eventually emerge (3). This process leaves small tears in the willow branch made by the ovipositor of the female cicada. All Oregon cicada species are annual and have overlapping generations, meaning they lack the famous boom and bust cycles of their famous eastern cousins. Our lovely lady is known by the charming common name ‘gloomy cicada’(Okanagana tristis).
Butterflies and moths were also out in great numbers, enjoying the nectar of the blooming flowers. The most common butterfly we saw was Edith’s checkerspot (Euphydryas editha), a small orange and white butterflie also found throughout Washington. One of my favorites was Langton’s forester (Alypia langtoni) which has striking white polka dots on fuzzy black wings.
The caterpillars were fewer in number, but almost rivaled the butterflies with their striking colors!
Along the trails we walked for the survey, the introduced and edible species wild carrot (Daucus carota) commonly known as Queen Anne’s Lace grew tall. It was a favorite among the insects, with beetles often found on its lacy heads. On one of my walks I passed a wild carrot flower with three beetles on it, and while stopping to take a photo accidentally brushing the flower. On my way back, I passed the same flower, but didn’t see any beetles. Where had they gone? On closer examination I realized they were still present but had retreated deep into the flower in response to my disturbance.
If you do decide to forage some wild carrot, make sure you can distinguish it from its poisonous lookalike, poison hemlock. If you get desperate, squish the leaves between your fingers and smell – wild carrot will smell like carrots.
Other insect highlights included a native thistle full of bumblebees. Each thistle plant we came across was attended to with equal enthusiasm. But one of the most fascinating insects we saw was a praying mantis! This funny fellow was climbing through a post burn forest, and seemed unwilling to stop and say hello.
The insects populated the landscape with activity, keeping us company through the hot summer days. Though often overlooked when we talk about the beauty of our ecosystems, the color and forms of insects are fascinating and varied. They are at the mercies of large and powerful forces, but respond so sensitively to the world around them. In their quick movements and subtle shifts you can see them and process and adjust to the constant myriad of changes in their environment. And despite living in a miniature world, they have a massive impact on the ecosystems. Though you may have to stoop down to see them, insects and their tiny dramas are endlessly fascinating, unfolding at the smallest scale in front of our eyes.
References:
1 Thermoregulation and Adaptation to Temperature in Dragonflies (Odonata: Anisoptera) by Michael L May
2 Life Cycle and Biology by British Dragonfly Society
3 The Ecology, Behavior, and Evolution of Periodical Cicadas by K S Williams, and C Simon
5 Butterflies and their Caterpillars of Columbia County, Oregon by Wild Columbia County