The ever-increasing diversity of Oklahoma beetles

My idea to return to Oklahoma’s Gloss Mountains this spring actually began taking shape during last year’s fall visit to the area, when I found a single Chrysobothris octocola adult on a dead mesquite (Prosopis glandulosa) branch. While common across the southwestern U.S. in association with this plant, its occurrence in the Gloss Mountains represented a northeastern range extension and new state record for Oklahoma! On that same trip I also collected an interesting beetle in the family Rhipiphoridae representing the species Toposcopus wrightii—also not previously recorded in the literature from Oklahoma. Combined with finding Acmaeodera macra here the previous year, it was becoming clear to me that area held good potential for other more typically southwestern species of wood boring beetles. Although I had by then visited the area several times, most of these visits were more focused on tiger beetles rather than wood boring beetles. If I could find such interesting species of wood boring beetles when I wasn’t focused on them, imagine what I might find if I timed a visit in late spring when such species should be at their peak of adult activity.

Chrysobothris quadrilineata | Gloss Mountains State Park, Major Co., Oklahoma (new state record).

Of course, success came quickly during this early June visit. I immediately found C. octocola common on the mesquite and would collect a nice series of voucher specimens before the day was over, and the second species I encountered, also on mesquite, was the longhorned beetle Plionoma suturalis—another new state record! I spent a bit of time working the mesquite, and when I had collected a sufficient series of both species, I turned my attention to the eastern red-cedars (Juniperus virginiana) in the area. Actually, I had had my eye on the red-cedars since last fall, when I noticed that nearly every tree had dead branches mixed in amongst the living branches. Closer examination revealed the workings of jewel beetle larvae in all of these dead branches, and a few larvae typical of the genus Chrysobothris were cut from one of the branches. A common species in the Great Plains associated with Juniperus is C. ignicollis, but these larvae looked rather big to represent that species, so I bundled up some dead branches and brought them back home for rearing but forgot to check on them before I left on this trip. At any rate, I walked up to one of the red-cedars, placed my beating sheet under a dead branch, gave the branch a whack with the handle of my net, and onto the sheet fell a rather robust Chrysobothris that I didn’t immediately recognize. I knew it wasn’t C. ignicollis, a much smaller species that I have collected on numerous occasions, so I thought maybe it could be C. texana, another western Juniperus-associate that I’ve collected less commonly. Still, the robust body and broad, distinct elytral and pronotal ridges had me second guessing that identification (especially after I found some individuals that looked more like what I remembered C. texana looking like). Over the next two days I beat hundreds (literally!) of dead juniper branches, finding many C. ignicollis but every now and then getting also one of these big, robust individuals.

Adults were beaten from dead branches on live Juniperus virginiana (new adult host).

After returning home, I checked my heavily annotated copy of Fisher (1942) and quickly determined the robust specimens as representing C. quadrilineata—a rather uncommon species and one that I’d never collected before. Described by LeConte in 1860 from New Mexico and recorded early in the 20th century from Arizona, Nevada and California, it has in more recent years been found to occupy a rather wide distribution across the western U.S., including Texas (Barr & Westcott 1976), Colorado, Oregon, South Dakota (Nelson et al. 1982), and Utah (Nelson 1987). Notice one state that is not in that list—Oklahoma! That’s right, another new state record! I later found photographs of this species on BugGuide taken in the very same area a year earlier (7 June 2012).

Adults also emerged from dead J. virginiana branches collected Sept. 2012 (first reported larval host).

When I returned home, I also checked the rearing cans and found several adults had emerged from the branches I collected last September. The only host associations that have been recorded for this species are adults collected on Juniperus californica (Linsley & Ross 1940) and J. pachyphloea [= J. deppeana] (Barr & Westcott 1976). Thus, J. virginiana not only represents a new host record for the species but is also the first known larval host. Considering how broadly distributed across the western U.S. this species is, it seems likely that it utilizes a number of Juniperus spp. throughout its range.

REFERENCES:

Barr, W. F. & R. L. Westcott. 1976. Taxonomic, biological and distributional notes of North American Chrysobothris, with description of a new species from California (Coleoptera: Buprestidae).  The Pan-Pacific Entomologist 52(2):138–153.

Fisher, W. S. 1942. A revision of North American species of buprestid beetles belonging to the tribe Chrysobothrini. U. S. Department of Agriculture, Miscellaneous Publication 470, 1–275.

Linsley, E. G. & E. S. Ross. 1940. Records of some Coleoptera from the San Jacinto Mountains, California.  The Pan-Pacific Entomologist 16(2):75–76.

Nelson, G. H. 1987. Additional notes on the biology and distribution of Buprestidae (Coleoptera) in North America, II.   The Coleopterists Bulletin 41(1):57–65.

Nelson, G. H., D. S. Verity & R. L. Westcott. 1982. Additional notes on the biology and distribution of Buprestidae (Coleoptera) of North America.  The Coleopterists Bulletin 35(2) [1981]:129–152.

Copyright © Ted C. MacRae 2013