Mt. Diablo was a lovely place to visit today, though it was 94 degrees up at 1,000 feet altitude along the Burma Road trail! The buckeyes I photographed two days ago were still blooming beautifully, and the blossoms were busy with bees and butterflies. Although the scientific literature says Aesculus californicus flowers are toxic to bees, the bees don’t seem to have read the literature!
Millions of tiny plant hoppers — they’re true bugs in the family Cicadellidae — bounced around in the tall grass and thistles. In the buckeye trees their bigger cousins, woodland cicadas — also true bugs in the family Cicadidae, don’t get the similar Latin names confused! — were warbling up in the leaves. These cicadas, in the genus Platypedia, have a cycle of two to five years, depending on the species. If you listen in the video below, you can hear the cicadas calling.
Butterflies flitted about the trees, too, Red Admirals, California Sisters, or similar species.
Up close, though, I saw several old friends lurking in the white blossoms — assassin bugs! These serious predators in the family Reduviidae lurk on flowers, waiting for pollinators to land, then they pounce! This is a species Kieran and I have met before, on Mt. Diablo and in Briones — they’re covered in spiny hairs that help them seize and hold their prey while they deliver the coup de grace with a sharp, piercing beak. They also sometimes carry Chagas Disease, although I don’t think this particular species falls under the “kissing bug” subfamily Triatominae which carry it. I’ve been bitten by one of these assassin bugs before, and it hurt like fury but there were no other ill effects.
Assassin bugs live up to their name — that bite hurts! You can’t say they didn’t warn you, either, as they have prominent, bright red markings like a black widow spider that say “Don’t touch!”
I saw several of them flying between the blooming buckeye trees, looking for better spots to ambush prey. They seemed to prefer the sunny sections of the trees.
It was 94 degrees at noon along Burma Road trail on Mt. Diablo.
Millions of tiny leafhoppers populated the fields. One is visible on this flower-seed head.
Although Aesculus californicus flowers aren’t supposed to be good for bees, the bees don’t seem to know that.
Lurking in ambush beneath one bunch of blossoms was a black assassin bug with bright red warning markings.
A second assassin bug on a different tree. The many hairs all over its body and powerful legs help it grasp prey.
Steven E. F. Brown 