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Yesterday I made one of my night-time forays over to Sabino Canyon. After 7 p.m. darkness descended quickly and soon it was pitch black with just a minuscule amount of moonlight penetrating the clouds. When it gets that dark I depend entirely on a flashlight to see and my observations are limited more or less completely to whatever falls within the flashlight’s beam. I was walking near the riparian area in the canyon, where the canopy of cottonwood and willow trees made the darkness even more total, when I caught a slight bit of movement on the ground just at the edge of my flashlight’s beam. I looked closely and saw this.
It was a very large wasp and she was dragging something with her. She was walking backwards and struggling to pull an object that was substantially larger than she was.
The wasp was a member of the genus Pepsis and she was dragging a large female tarantula. Pepsis wasps are referred to colloquially as “Tarantula Hawks.” There are nine species of these wasps that live in our local desert and some of them, as is the case with this one here, specialize in hunting tarantulas. A pepsis wasp can be huge. I’d estimate this one to be about two inches long, but she is nevertheless dwarfed by her prey.
How does a wasp like this one hunt? The wasp actively searches for tarantulas’ burrows. When she finds one, she taps on the silk that the tarantula has stretched over the burrow’s entrance. The tarantula, sensing an intruder or prey, rushes out of the burrow, to be confronted by the wasp. There then ensues a battle in which the wasp seeks to sting the tarantula and the tarantula, for its part, seeks to bite the wasp. If the wasp succeeds, her venom paralyzes the spider. Sometimes she fails and occasionally, ends up as a meal for the tarantula.
The successful wasp drags the paralyzed but still living tarantula, either down into its burrow, or into a burrow that the wasp has dug. She entombs the tarantula, but before doing so, lays a single egg on the tarantula’s abdomen. When the egg hatches, the larva feeds on the tarantula, killing it. The larva eventually emerges as another wasp.
Only female Pepsis Wasps hunt. Males live a carefree existence, sipping flower nectar for food, and searching for females with whom to mate.
Tarantula Hawks on the prowl are a fairly common sight in late summer. It’s a little eerie to realize that every one of these wasps represents a dead tarantula that nurtured it as an infant.
I’ve posted photos several times of Pepsis Wasps but I’ve never before captured a victorious wasp with her prey. It’s something I’ve been searching for for years and I’m delighted to be able to show these photos — not without a tinge of regret, however, for the tarantula. Nature, in all of its beauty, can be very brutal.
Images made with a Canon 5DS-R, 180 f3.5L Macro Lens assisted by Canon 600EX-RT Speedlite, ISO 125, M setting, f13 @ 1/160.