Clouded beetles amidst spectacular scenery

“Westerly from Westgard Pass is a view equaled in few parts of America. In the middle distance, a dozen miles away and nearly a mile below, lies the fertile Owens Valley, extending at right angles north and south over a hundred miles, and on the farther side, distant a score of miles, tower the snow-clad Sierras, with serrated crests and symmetric domes and peaks outlined against the sky at an approximate height of two and one-half miles vertical above the level of the ocean, and extending north and south far as the eye can see. The vision is rich reward for a journey of a thousand leagues.”—A. L. Westgard, March 1915

View of Westgard Pass from higher up in the White Mountains near Ancient Bristlecone Pine Forest.

View to Westgard Pass from higher up in the White Mountains near Ancient Bristlecone Pine Forest.

After a morning spent searching for Crossidius coralinus caeruleipennis (perhaps the most sublimely beautiful of the subspecies) in the high desert sage of the wide open Owens Valley floor near Bishop, California, we made the short drive south to Big Pine, turned sharply left, and began the slow, twisting ascent through a narrow gap between the White Mountains to the north and the Inyo Mountains to the south. Eventually reaching an elevation of 7,313 ft,  Westgard Pass serves as access to Earth’s oldest living things! and, in doing so, provides some of the most striking scenery in the entire Basin and Range Province of eastern California.

Westgard Pass, Inyo Co., California.

Chrysothamnus viscidiflorus (small plants with yellow flowers) host Crossidius hirtipes nubilus adults.

Field mate Jeff Huether and I no doubt wanted to see the grotesquely beautiful trees growing in Ancient Bristlecone Pine Forest and were happy to enjoy the magnificent scenery along the way, but our trek to Westgard Pass had also a strictly entomological purpose—to search for Crossidius hirtipes nubilus, among the most uniquely colored and geographically restricted of the C. hirtipes subspecies. Approaching the summit, the narrow, rocky gorge opened up to a broad expanse of pinyon/juniper woodland, and nestled among the ubiquitous sage we found the plant we were looking for—yellow rabbitbrush (Chrysothamnus viscidiflorus) in full bloom.

Crossidius hirtipes nubilus (male) on flowers of Chrysothamnus viscidiflorus.

Crossidius hirtipes nubilus (male) on flowers of Chrysothamnus viscidiflorus (field photo).

It took a while, however, before we found the beetles that we were looking for. Robust gray rabbitbrush (Ericameria nauseosa) plants in full bloom conspicuously dominated the roadsides and demanded our initial attentions, but our only reward was the widespread Crossidius ater. Not even a single Crossidius coralinus specimen could be claimed as consolation. Still, we knew the real quarry was further back from the roadsides, on the much smaller and less conspicuous yellow rabbitbrush that serves as an adult host for Crossidius hirtipes and most of its subspecies. Once we turned our attentions to these smaller plants we found the first adult fairly quickly, but precious few were seen considering the many plants that we examined until we finally zeroed in on one area just south of the summit where the beetles seemed to occur with slightly greater frequency. While not numerous, we eventually found enough beetles for us to declare, “Let’s go see the bristlecone pines!”

In addition to their longer antennae, males are distinguished by xxx.

In addition to longer antennae, males are distinguished by less extensive clouding (studio photo).

This subspecies is among the most distinctive of all the C. hirtipes subspecies due to the combination of dark reddish-brown coloration and extreme, dark clouded area of the elytra (Linsley & Chemsak 1961). It most closely resembles C. h. rhodopus, which occurs further north in the Mono Basin, but that subspecies is not as dark and lacks the extensive clouding of black on the apical portions of the elytra.

Females have the elytral markings xxx.

Females have the markings greatly expanded to almost completely cover the elytra (studio photo).

The dark clouding actually represents an expansion of the dark stripe found along the suture of the elytra of many C. hirtipes subspecies, most of which exhibit sexual dimorphism in the degree to which this stripe is developed. In some subspecies the stripe is present in the females but absent in the males, while in others the stripe is present in both but more fully developed in the female. In C. h. nubilus the sutural stripe reaches an extreme state of development, covering much of the apical two-thirds of the elytra in the male and being so greatly expanded in females that almost the entire elytra are covered except for two small subbasal patches revealing the ground color of the elytra.

REFERENCES:

Linsley, E. G. & J. A. Chemsak. 1961. A distributional and taxonomic study of the genus Crossidius (Coleoptera, Cerambycidae). Miscellaneous Publications of the Entomological Society of America 3(2):25–64 + 3 color plates.

Copyright © Ted C. MacRae 2014

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About Ted C. MacRae

Ted C. MacRae is a research entomologist by vocation and beetle taxonomist by avocation. Areas of expertise in the latter include worldwide jewel beetles (Buprestidae) and North American longhorned beetles (Cerambycidae). More recent work has focused on North American tiger beetles (Cicindelidae) and their distribution, ecology, and conservation.
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9 Responses to Clouded beetles amidst spectacular scenery

  1. Anonymous says:

    Ted
    There’s nothing in the world like that part of North America. One of my favourite places.
    D Rentz

  2. Dave Rentz says:

    Ted
    One of the most spectacular places in the world and one of my favourite places. Beautiful photos. Thanks
    D Rentz

  3. Gunnar says:

    Great pictures. The identification information in the legends was a bit xxx, though.

  4. Dennis Haines says:

    If you ever get over to my neck of the woods we can make the “Grand Expedition Crossidius”. Depending on if you have two or three days (or just one available) we can collect C. coralinus ferruginosus, C. c. ruficollis, C. c. tejonicus, C. c. ascendens, C. suturalis minutivestis, C. mojavensis, and C. hirtipes flavescens (not to mention C. ater). There’s also the possibility of running into C. discoideus (undescribed subspecies).

    One day would allow for 5-6 of the above. Two days would allow us to hunt down an additional two. Three days would allow for all. C. hirtipes flavescens is in the most remote area and takes a fair amount of driving to access from my side of the Sierra Nevada. C. coralinus ferruginosus is a variable thing that occurs in tan with coral-pink along the sides to dark red. The farther north you go the more red is present.

    • Gosh, do you have me salivating. I can tell you one thing if I get out that way to look for Crossidius I’m not gonna just give myself one day.

      I’d love to see C. coralinus ferruginosus in coral-pink!

      • Dennis Haines says:

        I used to take friends on the Grand Expedition sometime right after my birthday (Sept 15th) to celebrate. There used to be a large fresh-water lake (largest body of fresh-water west of the Mississippi, that separated the two subspecies of the San Joaquin Valley, ferruginosus on the north and ruficollis on the south. The host plant, Isocoma acradenia var. bracteosa. does not occur on the flood plain of the old Tulare Lake, effectively isolating the two populations. Still, around the north shore of the lake bed ferruginosus is tan to testaceous with pink down the sides. By the time you get into Fresno County there tends to be a mix of testaceous and mirky red individuals. Then in San Benito and Merced Counties they are red with the expanded black spot in the females, and reduced spot in the males.

        C. c. tejonicus is unlike anything else in the species. It’s status as a subspecies of C. coralinus has long been questioned. It’s a nice, robust, red species that visits Chrysothamnus nauseosus mohavensis.

  5. James C. Trager says:

    I’m salivating at the lovely scenery, your cool beetle pictures, and all the ants that went unnoticed. :)

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