Cicindela albissima—The Coral Pink Sand Dunes Tiger Beetle

Coral Pink Sand Dunes State Park, Utah

The week had started off good, with three species of western sand dune endemic tiger beetles (Cicindela formosa gibsoni, C. scutellaris yampae, and C. arenicola) and a variety of sometimes spectacular Crossidius longhorned beeltes having been encountered.  Mid-week, however, had brought a lull in our success—the long drive to southwestern Idaho was not rewarded with finding C. waynei, endemic only to Bruneau Sand Dunes State Park, and an even longer drive was required to backtrack and then drop down to the southwestern corner of Utah in hopes of finding the equally rare and restricted C. albissima.  Had it not been for our continued success with different species and subspecies of Crossidius longhorns the drive might have felt like a lesson in futility.  Still, on a collecting trip a new day and new locality brings new hope, and anticipation grew as we passed through lodgepole pine forests on stunning black lava fields and wind-carved red sandstones on the final approach to Coral Pink Sand Dunes State Park.

Colored pink by iron oxide minerals, the dunes are estimated at 10,000 to 15,000 years old.

Words cannot describe the stunningly spectacular landscape that unfolded before us as we entered the park.  The scenery alone makes Coral Pink Sand Dunes worthy, in my humble opinion, of National Park status, but it is C. albissima—occurring only on the park’s vivid pink dunes and nowhere else in the world—that makes this place truly special.  Precisely where in the park the beetle lives is a matter of public record, as Chris Wirth (author of the intermittent but highly focused blog Cicindela) and Randolph-Macon College Professor Emeritus Barry Knisley have produced a wonderfully detailed and well illustrated brochure about the beetle and its life history, population trends, and limiting factors.  What remained to be determined was whether the beetles would be active during the brief window of time available to look for it.  Cicindela albissima is a so-called “spring-fall” species in reference to the bimodal adult activity period, but activity in the fall is much less predictable than in the spring depending on moisture availability.  The day was perfect—temperatures in the 70s by mid-morning, only a light breeze, and a sharp, blue, cloudless sky.  All we could do was look.

Adult beetles were found on the northern edge of this dune. A majority were seen amongst sparse vegetation rather than barren areas.

It didn’t take long really to find them, as the adults were already out in encouragingly strong numbers. Of the several dozen adults we saw, all but one were seen atop the northern edge of one particular sparsely vegetated dune.  I suspect the larval burrows were at the bottom of the steep northern dune escarpment in the more stable wind-scoured sandstone clays that lay between individual dunes.  Vivid white and floating across the sand on long delicate legs, the elegance of their beauty was a stark contrast to the harshness of the surrounding landscape.  With a miniscule range of only 400 hectares, C. albissima is one of North America’s rarest tiger beetles, and I felt truly priviledged to join the small ranks of those who have seen this beetle alive in its native habitat and could appreciate the significance of the event.  Of course, the sense of accomplishment would not be complete unless I also succeeded in photographing the species in the field, and although the adults were quite wary and active, I was happy with several of the photos that I ended up with.  Similar to what I observed with C. arenicola, adults amongst the vegetation seemed slightly less skittish than those out in the open, so it was in the vegetated areas that I concentrated my efforts.  My only regret was not adding extension tubes to allow some real closeup portraiture, but the beetles seemed far too wary to have put up with the decrease in working distance that would have entailed.  At any rate, here are some of my favorites:




What the future holds for C. albissima remains unclear.  Designation of the beetle’s home range as a preserve (albeit tiny) would seem to offer long term protection, but a  large portion of this area is open to off-road vehicular traffic (although not a single one was seen during the time that we were there).  An even greater threat exists in the potential for extended drought affecting the entire population, and as greenhouse gases continue to accumulate in the atmosphere the chance of impacts from unusual weather events only grows. I feel lucky to be among the few that have witnessed this beautiful species in nature, but I sincerely hope I am not among the last.

ORV tracks can be seen just outside the conservation area boundary

Copyright © Ted C. MacRae 2011

Crossidius coralinus fulgidus

Crossidius coralinus fulgidus | Uintah Co., Utah

Tiger beetles may have been the primary focus of last week’s 9-day, 10-state, 4,700-mile collecting trip; however, they were not the only beetles I was hoping to see. Longhorned beetles (family Cerambycidae) of the genus Crossidius are unusual in the family because of their fall rather than spring/summer adult activity period, and they just happen to occur in dizzying variety throughout the Great Basin and surrounding mountainous areas. Larvae of all species are presumed to feed on the roots of perennial, shrubby, fall-blooming composites, primarily in the genera Chrysothamnus, Ericameria, Gutierezzia, and Haplopappus (Linsley and Chemsak 1961), with the adult activity period undoubtedly timed to allow congregation and mating on the late-season blooms of their host plants.  Only 13 species are currently recognized, but these are further divided into 37 subspecies and innumerable locally distinct populations.  Not having spent much time in the mountain west during the fall, this group has till now been poorly represented in my collection.

The species shown here, Crossidius coralinus fulgidus, was among the first of many that we encountered during our trip.¹  This population was seen near Vernal in northeastern Utah.  It was late in the day and the adults had settled for the night onto the flowers of their host plant, Ericamera nauseosa.  Flower-visiting longhorned beetles are notoriously frustrating subjects to photograph, as their constant movement and long legs and antennae make focus and composition difficult.  These beetles had essentially ceased activity, allowing me to carefully compose and focus the shot, and the low sun in the western sky provided a bright blue eastern sky to use as a colorfully contrasting background.  The photo above (the very long antennae identify it as a male) was taken hand-held with my Canon 100mm macro lens at ISO 400 and 1/60 sec to allow exposure of the sky and flash at an aperture of f/16 to illuminate the subject and achieve good depth of field.  My only criticism of this photo is the small amount of blur seen in the distal antennal segments.

¹ “We” refers to myself and Jeff Huether from Geneva, NY. Jeff is primarily interested in Meloidae but like me also has an interest in Cerambycidae. I was fortunate to have Jeff with me on this trip, as he has collected extensively throughout the Great Basin region and encountered nearly all of North America’s named species and subspecies of Crossidius. It is only because of his prior experience with this group that I was able to find this and several others that we saw during the trip.

ISO 100, 1/200 sec

ISO 400, 1/200 sec

ISO 400, 1/60 sec

Because the beetles were so calm, I spent some time with this female individual trying different settings to see their effect on background color, subject illumination, and detail.  All were taken hand-held using the same lens at f/16, with the left photo also using my “typical” settings of ISO 100 and 1/200 sec.  The background is very dark (in post-processing I might choose to make it black)—good for some subjects but not this one, and although the focus is good the lighting is rather harsh (I had to decrease highlights in post-processing much more than I normally like).  The center photo was taken with ISO increased to 400 and results in a much more pleasing, if still not very natural-looking sky background.  Focus remains good and the shorter flash duration needed reduces the amount of highlighting that needs post-processing adjustment.  Overall I like this photo the best except that the sky is not true in color.  The right photo is also at ISO 400 but uses a slower shutter speed (1/60 sec).  The sky in this photo is the most natural-looking, and as might be expected problems with flash highlights are minimal—it almost looks like a natural light photograph.  However, some amount of motion blur can be detected, especially in the antennae.  Perhaps intermediate shutter speeds (e.g. 1/120 sec) or slightly higher ISO might effectively deal with this while still allowing the truest colors.  What do you think?

REFERENCE:

Linsley, E. G. and 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):26–64, 3 color plates.

Copyright © Ted C. MacRae 2011

Coral Pink Sand Dunes tiger beetle – range map

Those of you on RSS feed might be interested in revisiting my previous post, Coral Pink Sand Dunes tiger beetle on ARKive.  I’ve added a Google screen shot to the post that shows a visual perspective of the entire range of Cicindela albissima within a tiny inset of the state of Utah.  The image provides a sobering reminder of just how vanishingly small the range of this species is.  If we, as a society, cannot take the steps required to ensure the survival of a beautiful little species such as this one – living on only the tiniest sliver of the lands under our stewardship, it speaks ill of our ability to do so for other species with much greater habitat requirements.

Copyright © Ted C. MacRae 2009

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Coral Pink Sand Dunes tiger beetle on ARKive

I’ve been meaning to write about ARKive for awhile now. ARKive is a unique collection of videos, images and fact-files assembled from among the world’s very best wildlife videographers and photographers in an attempt to create a centralized digital library of life on Earth. Their short to mid-term priority is the completion of audio-visual profiles for the 16,300-plus species on The IUCN Red List of Threatened Species, before moving on to profiling all species that have ever been filmed or photographed. With backing from many of the world’s leading conservation organizations, ARKive hopes to “promote public understanding and appreciation of the world’s biodiversity and the need for its conservation, through the power of wildlife imagery.”

With tiger beetle season almost now upon us, it seems appropriate to highlight the media collection that ARKive has assembled for one of North America’s most spectacularly beautiful and critically imperiled tiger beetles, Cicindela albissima (Coral Pink Sand Dune tiger beetle). This amazing species is not only stunning in appearance, with its nearly pure white elytra, but has perhaps the most restricted habitat of any tiger beetle species in North America – the entire population being restricted to 400 hectares within coral-pink-sand-dunes_3Utah’s Coral Pink Sand Dunes State Park and the adjacent Bureau of Land Management (BLM) dune management area (Pearson et al. 2006). The Google screen shot at right shows the entire range of this species as a light pink swath (inset shown on larger map of the state of Utah).  Regarded initially as a subspecies of the widespread C. limbata (sandy tiger beetle), recent molecular studies showed this beetle to be only distantly related to that species and, thus, deserving of full species status (Morgan et al. 2000).

Unfortunately, the beetle’s highly restricted habitat continues to be adversely affected by ongoing, recreational off-road vehicle use, especially in the interdunal swales used by the larvae. Impacts occur not only by direct run-over mortality, but also through disruption of normal adult and larval activity, damage to vegetation, reduction of arthropod prey of C. albissima, and mixing of the upper soil layer which increases desiccation of the larval microhabitat (Knisley and Hill 2001). The species was nominated for federal protection under the Endangered Species Act in 1996 (when it was still considered a subspecies of C. limbata), and two years later a Conservation Agreement between BLM, U.S. Fish and Wildlife Service, Utah Department of Parks and Recreation and Kane County was established in an effort to protect the critically sensitive habitats in which this species lives. Despite these conservation measures, ongoing monitoring and research within the protected areas has documented a continuing decline in the population, suggesting that these areas may not be of sufficient size to enable the population to increase, and off-road vehicle use continues outside of the protected areas (U.S. Department of Interior, Fish and Wildlife Service (FWS) 2008). While still only a candidate for federal listing as an endangered or threatened species, the FWS now considers the magnitude of the threat from off-road vehicles, in view of these recent findings, to be high and imminent. As a result, the FWS has increased the priority of the species’ candidacy from 8 to 2 (1 being the highest priority a candidate species can receive).

While I would dearly have loved to embed one of ARKive’s extraordinary videos or photographs of C. albissima within this post, copyright considerations do not allow that.  What I can do is provide hyperlinks directly to the site, and I encourage everyone to visit ARKive and see their images of this gorgeous species.

Photos by Christine Breton: adult beetle, dorsal view, adult beetle, adults mating, habitat

Videos by Ganglion Films: overview, adults mating, adult burrowing in sand, OHVs threatening protected habit.

In addition to the ARKive images, Chris Wirth, author of the blog Cicindela, has taken photographs of this species and presents stunning examples of both the larva and the adult in his post Cicindela albissima (Re-post). I myself am making plans to visit Coral Pink Sand Dunes – perhaps this season – to find and photograph this species for myself. When I succeed, rest assured those photographs will appear on this site.

REFERENCES:

Knisley, C. B., and J. M. Hill. 2001. Biology and conservation of the Coral Pink Sand Dunes tiger beetle, Cicindela limbata albissima Rumpp. Unpublished report.

Morgan, M., C. B. Knisley and A. Vogler. 2000. New taxonomic status of the endangered tiger beetle Cicindela limbata albissima (Coleoptera: Cicindelidae): evidence from mtDNA. Annals of the Entomological Society of America 93(5):1108-1115.

Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.

U.S. Department of Interior, Fish and Wildlife Service. 2008. 50 CFR Part 17. Endangered and threatened wildlife and plants; review of native species that are candidates for listing as endangered or threatened; annual notice of findings on resubmitted petitions; annual description of progress on listing actions; proposed rule. Federal Register 73(238) (December 10, 2008):75176-75244.

Copyright © Ted C. MacRae 2009

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