Enoclerus vernalis Barr & Rifkind

Barr, William F. & Rifkind, Jacques, 2009, Two new and one resurrected species of Enoclerus Gahan (Coleoptera: Cleridae: Clerinae) from the western United States, Zootaxa 2168, pp. 57-62 : 58-60

Enoclerus vernalis Barr & Rifkind , new species

( Fig. 1)

Type specimens. Holotype ♂: U.S.A., California, [Los Angeles County], Neenach , V-15-1926; label reads: "Pres. by J. O. Martin Collector. " Holotype deposited in CASC . Paratypes: 3 ♂♂, 1 ♀, same data as holotype ; 4 ♀♀ from type locality, V-17-1928, E. G. Linsley, collector. CALIFORNIA: Los Angeles County : 1 ♀, Mojave Desert, Llano , IV-13-1954, Wm. R. Lower, collector ; 1 ♀, Mojave Desert, Llano , IV-4-1953, A. Ebeling, collector ; 1 ♂, Palmdale , VI-1958, R. C. Willis, coll. ; 1 ♀, Pearblossom, 4 May , 1975, David. E. Bixler ; 1 ♀, 2 mi. S of Littlerock , May 18, 1988, G. Snelling, coll. ; 1 ♂, Juniper Hills , May 6, 1973, S. Vesos, on Joshua ; 1 female, Juniper Hills , VI-I-1975, A. V. Evans ; 1 ♀, 1.5 mi SW Littlerock, 22 May , 1975, Adriean J. Mayor, collected on Yucca whipplei ; 1 ♀, 17 mi. E. Gorman , IV-16-1962, G. W. Frankie, collector ; 1 specimen, sex unknown, Valyermo , V-1-1968, J. Powell, collector ; 1 ♀, Theo. Payne W. S., 20 May , 1976, P. H. Sullivan, coll. ; Inyo County : 1 ♂, Argus Mts. , V-22-1937 ; 1 specimen, sex unknown, Grapevine Canyon, Saline Valley , 5000', IV-20-1985, D. Giuiliani, anti-freeze pit trap; Kern County : 5 ♂♂, 5 ♀, 2 sex undetermined, Short Cyn. , 7 mi. NW Inyokern, IV-13-1954, J. W. MacSwain, collector ; 1 ♂, Red Rock Cyn. State Park, Red Cliffs Natural Preserve , 400 m, May 5, 1991, J. Rifkind, coll. , 1 ♂, Indian Wells Canyon, 3750', IV-17-1962 (c-3711), collection of N. L. Rumpp ; 1 ♂, Laurel Mt, El Paso Mts, 4500', 14 May , 1960, D. L. Tiemann, collector ; 1 ♀, 1 sex unknown, 3 mi. NW Indian Wells , IV-12-1954, J. M. Linsley, coll. , 1 ♀, 6.5 mi. NW Inyokern , IV-13-1954, J. W. MacSwain, collector ; Tulare County : 1 ♀, Kane Brak Brid. [probably " Canebrake "] ♀ Hwy. 178, on flower, 1 June , 1973, Lon Kincannon; San Bernardino County : 1 male, Cajon Pass , V-19-1937, coll. and pres. by E. Guedet ; 1 ♂ from Victoryville [sic], VI-6, J. N. Knull collection . Paratypes are deposited in CASC, EMEC, FMNH, UCR, LACM, CSCA, JNRC, WFBC , and WOPC.

Diagnosis. Distinguishable from its congeners by its unique elytral color pattern, and sub-lustrous elytral integument. It is most similar, and probably closest phyletically, to Enoclerus zonatus , and E. spinolae , but is disjunct both geographically and phenologically from these species (see Discussion below).

Description (Holotype). Length: 9.0 mm. Color: black to reddish black; mouthparts, antennae, bases of femora, tarsomeres, in whole or in part, reddish brown; elytra ( Fig. 1) with an irregular latitudinal antemedian red band, widest laterally, complete to lateral margins, slightly narrowed at suture posteriorly, somewhat extended along suture anteriorly; elytral apices broadly red; epipleuron reddish; abdomen uniformly red. Head: antennae robust, club compact, antennomere 11 sinuate internally, as long as antennomeres 9 & 10 taken together; front feebly bi-impressed, rugulose; cranium finely, densely punctate, sparsely set with fine, pale, suberect setae and fewer longer, erect, robust black setae. Pronotum: broader than long (5:4); narrower than elytra at base; sides arcuate; anterior margin broadly, shallowly emarginate; transverse impression distinct, broadly "V" shaped; disk broadly subflattened; surface finely, irregularly punctate and transversely rugulose, moderately vested with erect, pale and infuscate setae of varying lengths. Elytra: robust (ratio of length to maximum width approximately 3:2), widest posterior to middle; anterior margin bisinuate; humeri pronounced; subbasal tumescences feebly indicated; disk broadly subflattened; surface feebly shining, finely and densely but shallowly punctate and indistinctly roughened, covered moderately but inconspicuously with short, suberect black setae, interspersed with fewer, longer erect black setae; epipleural fold broad, subexplanate posteriorly; posthumeral margin broadly deflexed dorsally behind middle; apical slope shallow; apices dehiscent. Metasternum: convex; surface shining, rugulose, feebly punctate. Abdomen: shining; surface shallowly roughened, with scattered punctures, sparsely vested with fine, pale setae; visible sternite 5 with hind margin broadly, shallowly emarginate, sternite 6 subtruncate, tergite 6 with lateral margins convergent, hind angles rounded, and apex shallowly, sinuately emarginate; abdominal apex without setal daggers. Legs: robust; all tarsi well developed.

Variation. Size ranges from 7.5 mm to 11.0 mm. In the female, abdominal tergite and sternite six are conjointly subtruncate or conjointly rounded posteriorly, with a slight notch at apex. Integument color ranges from black to reddish black. Size and shape of the antemedian and apical elytral fasciae are variable, so that in some specimens, the reddish areas are more extensive than the black. Even in these cases, however, the black postmedian band is never incomplete internally for more than the width of the elytral suture. Two specimens from Lower Covington Flat, Joshua Tree National Park, collected in late May and early June, are problematical in this regard. Though taken in the Mojave Desert of California within the presumed flight period of this species, they exhibit a facies much more like that of E. spinolae from Arizona, with shining, somewhat more convex elytra, bearing reduced, internally interrupted postmedian black markings. At least one other broadly distributed member of the Sonoran and Chihuahuan desert clerid fauna (i.e. Aulicus edwardsii (Horn 1880)) has outlier populations in and near Joshua Tree National Park (Mojave and Colorado Desert), and the present case may prove to be similar. In light of our uncertainty about the identification of the Covington Flat specimens, we have chosen not to include them in the type series of the new species.

Discussion. Enoclerus vernalis belongs to a group of similarly large, robust, black and red patterned Enoclerus species that are associated with various Yucca (Agavaceae) species in the American West and Mexico. The most widespread species, E. spinolae , is known from Arizona, New Mexico, Texas, Colorado, Utah and Kansas in the United States, as well as the northern Mexican states of Chihuahua, Durango and Sonora. It is characterized by its red elytral base, with black humeral maculae; its postmedian black elytral markings are often reduced to small spots and are only rarely complete at the suture. This species flies from late May through August, and appears to be most common in middle to late summer, at least in Arizona. It is usually seen running or flying about blooming yucca, where it is conspicuous against the cream-colored flowers and green stalks of the plant. Enoclerus zonatus is distinguishable by its broadly darkened elytral base, with the postmedian elytral black marking in the shape of a transverse band. It has a more southerly distribution, and occurs in the Mexican states of Tamaulipas, Zacatecas and Hidalgo, where it has been taken in July and August. A third species, E. agave Barr (1976: 19) , known only from Chiapas in extreme southern Mexico, is readily identifiable by its black elytral posterior third. In comparison with the aforementioned species, E. vernalis is the only member of this group to commonly have more of its elytral surface black than red. Its flight period is primarily middle to late spring (with most records in April and May, and an occasional early June capture), and its distribution is restricted to the northern and western part of the Mojavean biogeographical province of California, where it seems to be associated with the Joshua Tree ( Yucca brevifolia Engelmann 1871 ).

Foster & Barr (1972: 124) recorded the larvae of E. spinolae (as E. abdominalis ( Chevrolat 1835: 52)) feeding upon the larvae of a weevil, Peltophorus polymitus Boheman 1845 , which were boring in the stalks of Yucca thompsoniana Trelease in Texas. Based on this and other observations and collecting data, it seems likely that various Yucca species serve as the preferred, or perhaps even obligate, microhabitat for the larvae and adults of all Enoclerus species in this group.

Etymology. The specific epithet "vernalis" refers to the spring flight period of the new species.

Distribution. Northern and western Mojave Desert of California.