Story & Photos By: Jim Moore
There is a family of beetles called Longhorn Beetles, comprising over 35,000 distinct species, many of which are some of the largest and most beautiful of insects. Many are creatures of the night, but some are daytime beetles renown for their role as efficient pollinators. These are the Flower Longhorn Beetles, with over 1500 species worldwide, including this story’s featured critter: the Yellow Velvet Longhorn Flower Beetle (species Lepturobosca chrysocoma). I first encountered and collected a specimen of this glistening beetle, well before I gained access to the internet; and at the time I was unable to determine its latin species name, or even if it had a common english name. In those days I simply invented simple descriptive names for the bugs that I collected; and chose the name Yellow Velvet Longhorn Beetle, since its iridescent glow in the sunlight reminded me of yellow velvet silk.
Once online, I did find it’s latin species name via the BugGuide website; but could not find any curently used, common English names. When I first uploaded photos to BugGuide I just used the name Yellow Velvet Longhorned Beetle. Later, when I learned that ‘chrysocoma’ means ‘golden-haired’ I then began using the name Golden or Golden-haired Longhorned Beetle for other photos submitted online. At the time it did not occur to me that other folks looking online to identify the same species of beetle would adopt my own made up common names, or invent the same names themselves, and use them in various forms for their own internet submissions. But now when I type in ‘Lepturobosca chrysocoma’ that is what I find! Interesting!
The golden iridescent hairs lie flat on the wing covers pointing away from the mid-line, and glisten differently depending on the angle of the sunlight as the beetle moves about on the flower. They vary in length from 10 to 20 mm (about 1/2 to 3/4 inch). The ‘longhorn’ term refers to the antennae, which can be very long in some other Longhorn Beetle species.
The Yellow Velvet Longhorn Beetle is a common and widespread species in the Western United States, and across the Northern States and Southern Canada. It is also quite common within the NorCal Cascade and Sierra Mountains, and is usually out and about during the mid summer months. The adult beetles are found in montane mixed forest and meadow habitats visiting all sorts of wildflowers feeding on pollen. This is where most people will see them on the flowers, and oftentimes covered with ‘yellow’ pollen! Yellow Velvet longhorns, and other flower longhorn species, are strong fliers, efficient pollinators; and are recognized as being vital to ecosystems where bee populations are in decline.
The larvae of Yellow Velvet Longhorns are wood borers that feed on the decaying wood of pine, spruce, alder, and aspen trees; and in this they serve their local environment as decomposers of the wood they feed on. However, the larva cannot actually digest the wood they eat; they need help from a species of yeast, which are single-celled microorganisms and members of the fungus kingdom. When a female Yellow Velvet Longhorn lays her eggs on deadwood the eggs are coated with live yeast cells from within her own internal biome. When the larva ‘eat’ their way out from their eggshell they ingest the yeast cells, and thus inoculate themselves, creating the symbiotic relationship needed. The yeast digests the chewed wood that the larvae consume, breaking it down into simple nutrients necessary for the growth of the larva. When the larvae undergo metamorphous into adult beetles the living yeast remains within them waiting to be passed on to the next generation!
As we continue to learn about such symbiotic relationships, we begin to realize how interdependent whole ecosystems are upon all the life forms within; and then we must also consider how important it is to protect these amazing beautiful living communities.
