SCV Outdoor Report: Repugnatorial Stinkbugs
By Wendy Langhans
What's the worst thing you've ever smelled? A pair of "forgotten" gym socks? Leftovers tucked away at the back of the fridge? A dog who had an unfortunate encounter with a skunk?
Last Saturday, Mr. Langhans and I went for a wildflower hike at the Tejon Ranch Conservancy property near Arvin, about a 75 minute drive north of Santa Clarita. While there, we encountered a few other six-legged hikers, Pinacate beetles, also know as Darkling beetles or "Stinkbugs".
A Stinkbug in defensive posture
You don't want to mess with these beetles. When disturbed, they elevate their hind quarters, so that they look like a jacked-up pickup truck. And if this warning posture isn't enough of a deterrent, their next step is to let loose with a spray of dark liquid from their pydigial glands. Not only does it stink, but it can also stain your skin brown. And if it gets in your eyes, it stings. Entomologists came up with a term for these defensive glands - repugnatorial. I think it fits.
Stinkbugs do provide a useful service, though. They eat the "detritus of grasses and forbs" (for those of us who don't speak "botany-ese", that means decomposing grasses and flowering plants). Right now our grasslands are at their peak of verdant ripeness. But soon, we will enter the dry, hot summer months and there will be plenty of dry grasses and flowers for the Stinkbugs to eat.
A field of grasses and wildflowers
Which raises an interesting question: how do Stinkbugs manage to survive the summer heat? Stinkbugs are black, and we know that black absorbs solar radiation. As it turns out, they have two adaptations: (1) their long legs and up-tilted posture keeps their bodies above the hot soil and (2) they have a subelytral cavity, an air space between their fused wing covers and their backs, that may serve as a thermal buffer.
The subelytral cavity may also serve as an extra tank for storing water. This could prove useful, especially if the Stinkbug has to repel more than one curious two-legged hiker.
Upcoming Outdoor Events:
Saturday, April 17, 8-10 AM. Early morning bird hike at Towsley Canyon. It's an easy 1 mile walk and beginning birders are welcome. For map, click here.
Sunday, April 18, 1-3 PM. Spring Wildflowers at East & Rice Canyons. It's that time of year! Join Wendy on a hunt for the colorful wildflowers. For map, click here.
Trail Maintenance Schedule. Come join our volunteers as they help maintain our trails. Contact Steve at email@example.com for time and place.
Wednesday mornings, April 7, 14, 21 & 28.
Saturday mornings, April 10 & 24
You can listen to stories like this every Friday morning at 7:10 a.m. on "The Hike Report", brought to you by your hometown radio station KHTS AM1220 and by the Mountains Recreation and Conservation Authority.