After spending the first four days of our Great Basin Collecting Trip (GBCT) traveling around west-central Nevada, we dropped down into California and traveled south next to the eastern flank of the Sierra Nevada towards Mono Basin. We had two goals for the day: 1) a very localized population of Crossidius hirtipes known from “Kennedy Meadow” and described originally by Chemsak & Linsley (1959) as C. rhodopus flavescens but transferred to a subspecies of C. hirtipes in their revision of the genus (Linsley & Chemsak 1961), and 2) the stunningly beautiful C. coralinus monoensis! Before reaching the first destination, we were temporarily distracted by the inviting shores of Topaz Lake just after crossing the Nevada/California state line, where we found only a few extremely wary Cicindela oregona oregona darting across its muddy banks. We then spent a good portion of the day in a futile attempt to find C. h. flavescens—one of only two Crossidius subspecies we did not find out of the 16 species/subspecies that we had targeted for the trip. Our failure to find this subspecies was largely a consequence of going to “Kennedy Meadows” in Tuolumne Co. rather than “Kennedy Meadow” further to the south in Tulare Co.! (Note to self: pay attention not only to the name of the locality but also the county!)
As a consequence of the day’s distractions and diversions, we didn’t arrive at the C. coralinus monoensis locality until quite late in the day. Fortunately, we were looking for a C. coralinus subspecies rather than a C. hirtipes subspecies, as the latter seem to have the habit of retreating down from the flower heads of their host plants starting around 5 p.m. and not coming back up until mid-morning the following day. Crossidius coralinus subspecies, on the other hand, seem to stay put on the flower heads through the night, perhaps burying themselves inside the flower heads but not retreating down from the plant. As a result, they may still be found during the late afternoon and early evening hours. Because of this, we still had a chance of finding them (if they were there) despite our late arrival, and only a few minutes passed before I found a male (first photo) on flowers of gray rabbitbrush (Ericameria nauseosa). The appearance was so strikingly different that I wasn’t even sure what I had found at first—I knew it wasn’t a C. hirtipes subspecies, but the bright orange coloration and relatively smaller size were quite different from the larger, red/black C. coralinus subspecies that I had seen to that point. Once I found a female, however (second photo), I realized that we had found C. coralinus monoensis.
This subspecies is immediately distinguishable from the C. c. temprans we were collecting further north in Nevada (and, in fact, most other C. coralinus subspecies) by its bright orange rather than dark red coloration. We found only a handful of individuals (as we did two days later when we passed by the site again), and their average size was considerably smaller than the former as well. The subspecies does greatly resemble C. c. caeruleipennis, found still further south at much lower elevations in Owen’s Valley (and a target for the following day) but differs by its smaller average size and presence of distinctly expanded black elytral markings and apical and basal black pronotal bands.
Chemsak, J. A. & E. G. Linsley. 1959. Descriptions of some new Cerambycidae from Mexico and southwestern United States. Journal of the Kansas Entomological Society 32(3):111–114 [preview].
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 2013