A Psychedelic Night Trip

Caterpillars from Florida Canyon, Santa Rita Mts.

Last Saturday we set up our black lights at the parking lot of the trail head next to the research station in Florida Canyon. We got some interesting beetles, moths and antlions, but mostly our sheets were inundated with small brown dynastini  of the genus Oxygrilius - and there were so many that one could hardly find anything else. So we left the black lights and wandered up the trail into the canyon. It was very dark because the moon had set behind the mountains quite early. I had never seen the narrow trail so overgrown with tall grasses and prickly leguminous bushes. So we had to walk behind one another and go slowly because in places it's rocky, though not very steep.

Olios giganteus

Then, in the beam of our flashlights, magical creatures appeared, their colors more vibrant than ever against the dark background. There were big spiders waiting for prey and katydids climbing on long spindly legs.

Apiomerus longispinis and A. flavivestris

Several species of Bee Assassins  seemed to be resting, while night active flightless cactus beetles like the longhorn Moneilema gigas and the round little weevils, Gerstaeckeria sp., were coming out to feed under the protection of the darkness.

Moneilema gigas and Gerstaeckeria sp.

By far the most striking shapes and colors are those of the caterpillars of our big moths and butterflies. Nobody was camouflaged and hidden away. Flashing their colors, they announced or pretended to be poisonous or foul tasting.

Pipevine Swallowtail, Battus philenor

Royal Moth Citheronia splendens sinaloensis

Syssphinx montana

Syssphinx hubbardi

Automeris cecrops pamina, Hodges #7748

Bizarre protrusions and appendixes made them look much more formidable and less vulnerable than simple caterpillars.

Estigmene acrea Salt Marsh Moth - Hodges#8131

The moths of the Salt Marsh Moth come from platinum blond to brunette in all hair colors imaginable. Even  siblings from the same clutch on the same food plant seem to show the whole spectrum.

Pygoctenucha terminalis  Hodges#8244. Moth photo by C.W. Melton

Hairs and bristles would spoil a predators appetite and even potentially  give overly curious humans skin rashes to remember (I do - I poked at the nest of  procession spinners in Greece many years ago).

Eacles oslari, Oslar's Eacles -Hodges#770

Oslaris moth have a wingspan that covers the lenth of my hand.

The white-lined Sphinx is one of many species of sphingids that appear regularly at our black lights.

Hyles lineata White-lined Sphinx - Hodges#7894

Some Moths are cryptic and camouflaged as adults, while the caterpillars sport bright colors and patterns.

Purslane Moth Euscirrhopterus gloveri. Moth photo Arlene Ripley

Lirimiris truncata  Hodges#8027. moth photo by Randy Hardy

 If you think about it, all this fantastic, and probably costly beauty must be geared exclusively towards interspecies predation  avoidance, because there is really no (known) reason for caterpillars to signal to or even recognize members of their own kind visually.  One could speculate of course that an egg-laying female might avoid an already heavily populated area to minimize competition for her own brood. I'm not aware of any research data supporting this hypothesis.