Category Archives: insects

Topic Is: Things Crawling on the Ground at Ahmanson Ranch

A Southern Pacific rattlesnake on the dirt road above the Victory Trailhead of Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch).
A Southern Pacific rattlesnake on the dirt road above the Victory Trailhead

I’ve encountered some interesting things crawling on the ground at Ahmanson Ranch this Fall.

Gopher snakes are the snake I see most frequently at Ahmanson Ranch (Upper Las Virgenes Canyon Open Space Preserve). Recently, I came across this sizable gopher snake crossing the dirt road on the long switchback above the Victory Trailhead. Despite the small size of its head, a gopher snake can consume prey much larger than might be imagined.

The impressively colored and patterned lime green caterpillar of the white-lined sphinx moth.
Caterpillar of the white-lined sphinx moth.

Just a few days ago — in virtually the same place as the gopher snake — I encountered a good-sized Southern Pacific rattlesnake serpentining across the dirt road and continuing up the brush-covered hill (video). The snake reminded me of a rattlesnake I photographed near the Victory Trailhead in November 2019. In the Fall, Southern Pacific and other rattlesnakes are said to return to the same den year after year. This rattlesnake had about 13 rattle segments, and the November 2019 rattlesnake about 10. Both were headed in the same direction. Might they be the same snake going back to a den?

On that same run as when I encountered the rattlesnake, I came across this remarkably colored and patterned caterpillar on Lasky Mesa. It turns out to be the caterpillar of a white-lined sphinx moth — a type of hummingbird moth.

A few days later — near the same place where I encountered the gopher snake and rattlesnake — I happened upon this tarantula scurrying across the road. Male tarantulas search for mates in the Fall.

Some related posts:
Ahmanson Trailhead Rattlesnake
Big Southern Pacific Rattlesnake at Ahmanson Ranch
Stuck in the Drive-Thru
September and October are Tarantula Months!
If It Looks Like a Hummingbird and Flies Like a Hummingbird…

Acmon Blue Butterfly on Narrow-leaved Milkweed

An Acmon Blue butterfly on narrow-leaved milkweed on Lasky Mesa. August 6, 2020.

An Acmon Blue butterfly on narrow-leaved milkweed on Lasky Mesa.

From a run in Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch) on August 6, 2020.

Some related posts: Painted Lady Butterflies in Upper Las Virgenes Canyon Open Space Preserve, Checkerspot Along the Garapito Trail, Tiger Swallowtail on Snow Plant

Tarantula Hawk with a Tarantula

Tarantula hawk with a paralyzed tarantula.
Tarantula hawk wasp drags her hapless prey to her burrow.

I was running down a narrow trail at Ahmanson Ranch, concentrating on the irregular terrain, when I suddenly found myself jumping over something on the trail. As my consciousness caught up, it asked,

“Was that a tarantula?”

“What tarantula has a stripe of orange on its back?”

Landing, I stopped and looked back up the trail. Totally unperturbed, a female tarantula hawk wasp, its bright orange wings gleaming in the sun, was diligently working to move its paralyzed prey to a nearby burrow.

The quintessential elements of a nightmare, I watched as the large wasp assessed the huge spider. I could hear the question as she turned away from the spider, and then reading the ground with her feet and antennae, determined if she could drag the beast uphill over a small bump. Then, question answered, she proceeded to do so.

Here’s a 30 second video of the tarantula hawk with the tarantula.

Related post: Tarantula Hawk, Sting of the Tarantula Hawk, September and October are Tarantula Months

Painted Lady Butterflies in Upper Las Virgenes Canyon Open Space Preserve

Painted Lady Butterflies in Upper Las Virgenes Canyon Open Space Preserve. May 12, 2019.
Painted Lady Butterflies

Back in March, a profusion of painted lady butterflies in Southern California made headlines. The colorful insects were said to be passing through the area on their way to Oregon and other points to the north.

Two months later millions of the black, orange and white butterflies continue to be seen in the West San Fernando Valley, Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch), and other areas. Recently there has been an uptick in their numbers and there have been some remarkable displays of the flyers along local trails.

Painted lady in Upper Las Virgenes Canyon Open Space Preserve with the characteristic four eyespots on the hindwing.
Painted lady in Upper Las Virgenes Canyon Open Space Preserve with the characteristic four eyespots on the hindwing. Click for a larger image.

There are three very similar species of “lady” butterflies in the genus Vanessa — the painted lady (Vanessa cardui), the American lady (Vanessa virginiensis) and the west coast lady (Vanessa annabella). The Canadian Biodiversity Information Facility web site has a side-by-side comparison of these species and this post on BugGuide.net compares the American lady to the painted lady.

The lady butterflies I’ve looked at closely in Upper Las Virgenes Canyon Open Space Preserve have the identifying characteristics of the painted lady (Vanessa cardui). Here are an open-wing photo and a closed-wing photo of painted lady butterflies in Upper Las Virgenes Canyon Open Space Preserve.

This three-minute slow-motion video of painted lady butterflies in upper Las Virgenes Canyon reveals their fluid, bird-like flight. The purple flowers in the video are winter vetch, an introduced plant which is also more abundant this year.

Deadly Nightshade

The shadow of a crab spider on the petals of a purple nightshade.

Fanged and clawed, death waits,
On a highland of lavender, near a saffron spire.

The silhouette of a crab spider on the petal of a back lit Purple nightshade (prob. Solanum xanti). The blossom is about 0.8 inch (~20 mm) wide, which would make the span of the spider’s crab-like grasping forelegs about 0.25 inch (~7 mm). From a run at Sage Ranch Park on November 2, 2006.

Note: This is not a photo of Deadly nightshade (Atropa belladonna).