Saturday, September 21, 2013

A Re-Visit to Scissors Crossing and Vicinity, Post-Monsoonal Rains

I made a short trip to the area around Scissors Crossing in the Anza Borrego Desert today, to see what the heavy rains have yielded, about a month after they fell (the last trip was on August 30th). The most dramatic change since the last visit was a massive explosion of White-lined Sphinx Moth larvae, and many yellow composites blooming on the desert floor. There were not many beetles to be found, with the exception of quite a few Lytta vulnerata, a large, colorful blister beetle, and a new species for me.

The old corral area, a little west of Shelter Valley. The reddish plants on the ground were heavily nibbled by the caterpillars. Ravens and crows were busily eating the caterpillars.

The find-of-the-day: Lytta vulnerata. A "life-beetle" for me!

"Rabbit Brush," upon which the Lytta were found (other Lytta vulnerata were found on a different yellow composite that I have not yet identified).

A small pile of White-lined Sphinx Moth caterpillars. It was difficult not to step on them, they were so numerous. No caterpillar hunters (Calosoma or Callisthenes) seen, though.

Monday, September 2, 2013

A Diversion to the Algodones Dunes, Imperial County, California

About a week ago, some energetic thunderstorm cells dropped rain on the Algodones Dune system in Imperial County. We thought we would explore them to see what life might have been triggered into activity by the rain.

We chose to spend one night about eight miles south of Glamis, in a Palo Verde grove nestled up against the eastern edge of the dunes.

The vegetation was much less than what we observed last year in about the third week in September. There had been massive rainfall weeks before last summer, and the dune region was full of green growth, and insect and spider activity.

This year was still very rich, though, in arthropods, and vertebrates, as well.

Around dusk, a sandstorm was visible to the west. A warning went out for the Glamis area. Several thunderstorms were visible, here and there close by, but not overhead! The wind picked up and the sand started whipping, but in about an hour, everything calmed and the rest of the night was hot, calm and dark - perfect for observing insects and other creatures!

Sunset from the dunes. Eight miles S. of Glamis, August 31, 2013.

The habitat. This photo was taken in September of 2011, a dry year.

Bolbocerastes imperialis, male. Eight miles S. of Glamis, August 31, 2013.

Edrotes arens, a small tenebrionid species that I have searched for without success in the past. They were pretty abundant on the sand of the dunes after dark. Apparently, they mimic rabbit droppings, a nice adaptation in a food-poor environment! Eight miles S. of Glamis, August 31, 2013.

Temnoscheila sp. These beetles are real biters when picked up! Quite a few came to our lights throughout the night. Eight miles S. of Glamis, August 31, 2013.

Osmidus guttatus. Eight miles S. of Glamis, August 31, 2013.

A very small tenebrionid. Probably Triorophus sp. Eight miles S. of Glamis, August 31, 2013.

Cerenopus concolor. I've seen them regularly in the local deserts over the years. Eight miles S. of Glamis, August 31, 2013.

A very large solifuge. Its body length is about 30 mm. 

These scorpions were VERY abundant on the sand of the dunes after dark. They seemed to be scattered about 3 feet apart...everywhere. 

A Sidewinder. I found this snake by almost stepping on it as I started to stand up from kneeling in the sand. Looking down, I saw the snake only a couple inches from my leg. I staggered left and it moved to the right, and all was well! Then a photo session ensued, of course. Eight miles S. of Glamis, August 31, 2013.

Sidewinder, on the move. Eight miles S. of Glamis, August 31, 2013.

Close-up of the Sidewinder. Eight miles S. of Glamis, August 31, 2013.

Western Banded Gecko. This little lizard was oozing with personality. It would take a couple steps in the sand, lash its tail like a tiny cat, and stare intelligently ahead, in search of gecko-prey. Then it would stalk an inch or two forward and repeat the process. Eight miles S. of Glamis, August 31, 2013. 

Western Banded Gecko, portrait. Eight miles S. of Glamis, August 31, 2013.

Palo Verde seedlings. These were scattered widely, triggered by the rain.
Here are a couple photos from last September, showing the vegetative growth. The vines were still present this year, but were utterly dry and desiccated, although some showed new green growth from last week's rain. The yellow composites in the photo below were not out yet this year.

Vine growth, September 2012. Eight miles S. of Glamis.

Yellow composites, September 2012. About six miles S. of Glamis.

A Diversion to the Anza Borrego Desert: About One Week Following the Local Monsoonal Rainfall

Some excellent rain has fallen in the Anza Borrego Desert in the past couple weeks, with spectacular flash flooding in some areas about one week ago.

I took a little day trip down there this Friday, August 30, to see what sort of flowering and insect activity might have been triggered by the rain.

The Scissors Crossing area clearly received quite a bit of precipitation, and about one mile west of Shelter Valley, the ground was very moist still, and mushrooms were popping up all over the landscape! Not too much flowering was occurring, and not too many insects were out and about, but that might change in the days and weeks to come. A lot of green growth was starting to appear on the damp landscape, though.

Below are some photographs of beetles found, and the wonderful mushroom "bloom."

Acmaeodera gibbula, Scissors Crossing, Anza Borrego Desert, August 30, 2013.

Plionoma suturalis pair, Scissors Crossing, Anza Borrego Desert. This female did not seem to enjoy being bitten in the face during copulation, and struggled to leave while I watched the pair. When this photo was taken, the male was trying to restrain her. In seconds she wriggled free and flew off, closely followed by the male. August 30, 2013.

Plionoma suturalis pair, Scissors Crossing, Anza Borrego Desert. August 30, 2013.

This white species of mushroom was the most abundant about one mile west of Shelter Valley. August 30, 2013.

A young, fresh pair of the species shown above. August 30, 2013.

Another undetermined mushroom species. One mile west of Shelter Valley. August 30, 2013.

A mystery-fungus. I'm not even completely sure that this IS a fungus! There were several of these hemispherical growths on the ground. They had no real stalk penetrating into the ground. The "hemisphere" sat on top of the fibrous mat seen below it here. August 30, 2013.

NOTE: Euphoria fascifera WERE flying associated with mesquite trees near Shelter Valley, but they were all flying too fast and high to photograph. I had seen this species in this location in late August 2007, in similar post-monsoonal conditions.

Euphoria fascifera from 2007, near Shelter Valley, Anza Borrego Desert.