Bristly cylinder fly (Cylindromyia interrupta)

The Bristly cylinder fly (Cylindromyia interrupta) is one of those unusual insects that hikers often notice on flowers along sunny mountain paths. From afar, it may remind us of a small wasp with its reddish-black abdomen color and slender build, but in reality, it is a beneficial parasitoid fly without a stinger. Its elongated body is covered with stiff black bristles, and its wings are transparent with a darker central part, giving it a recognizable appearance while flying over meadow flowers.
In nature, it plays a dual role, as adults feed on nectar and thereby pollinate plants, while their larvae are parasitoids of other insects, mainly shield bugs. Encounters with it are most common in summer months, when in the hot sun it tirelessly searches for food on the white flowers of yarrow, which we so like to admire. Although it may appear somewhat menacing due to its strong bristles, it is completely harmless to us hikers and merely reminds us with its presence of the complex and important connections in the mountain ecosystem.
Hikers can observe this skillful flyer as it clings strongly to flowers with its legs, with its reddish abdomen prominently standing out against the light background of plants. Its presence testifies to the biodiversity of the environment that hikers like to explore, as parasitoid flies are a key link in the natural regulation of other insect populations. At the next stop on a flowering meadow, it's worth paying attention to these small but mighty inhabitants who enrich the paths we so like to walk with their activity.