Acmaeodera conoidea Fall, 1899

Hansen, Jason A., 2023, Acmaeodera (Coleoptera: Buprestidae): A new species of Acmaeodera Eschscholtz, 1829 from the southwestern United States, with three new synonymies, new state and host records, and a key to species occurring east of the Rocky Mountain states, Insecta Mundi 2023 (12), pp. 1-52 : 6-7

Acmaeodera conoidea Fall, 1899

Acmaeodera conoidea Fall 1899: 31 .

Acmaeodera yuccavora Knull 1962: 2 . New synonymy.

( Fig. 3a–f )

The two syntypes of A. conoidea , one of which was designated lectotype by Westcott and Bílý (2018) [ANSP], were compared to detailed images of the holotype of A. yuccavora , provided by the Chicago Field Museum as well as various Arizona specimens of the latter from private collections [JAHC, POKC, RLWE]. In my opinion, the types are conspecific. The original series of A. conoidea in the Horn collection was described as “small” by Fall (1899) and likely did not represent the full range of variation within the species. It is perhaps not a coincidence that Cazier (1940) noted similarities between A. conoidea and A. subbalteata LeConte, 1863 , just as Knull (1962) later remarked on similarities between A. yuccavora and A. subbalteata , as A. conoidea and A. yuccavora represent the same species. The original description of A. yuccavora notes four irregular transverse yellow elytral markings, although Knull acknowledges the markings vary considerably and connect in some specimens to form vittae, as seen in the two existing A. conoidea syntypes ( Fig. 3 ; Knull 1962; Westcott and Bílý 2018). Notably absent from the description of A. yuccavora is a comparison to A. conoidea , understandable since Knull did not have access to the type series at the time, long before the designation of the A. conoidea lectotype. The last published account of the type series was Cazier (1940), who mistakenly declared the type lost.

Horn’s series of A. conoidea was apparently composed of at least three specimens, only two could be located over a century later and were subsequently designated as the lectotype and paralectotype, respectively ( Westcott and Bílý 2018). Careful study of these types made it clear the previously concept of A. conoidea , as represented in published distribution records and among many specimens in collections, was in error. During the course of study for this work, specimens of the Acmaeodera tubulus species group from multiple collections were examined. Among those were specimens from west Texas labeled as A. conoidea that did not align with Fall’s (1899) description, but invariably represented the previously undescribed species, A. natlovei .

Confusion between A. conoidea and A. natlovei undoubtedly came about due to misplacement of the type series, variability among specimens of both species, and the subsequent misidentifications that appear to have been relied upon for comparison. Acmaeodera conoidea can easily be separated from all similar species of Texas Acmaeodera by its broadly emarginate clypeus, third lateral strial split near the umbone, and larval host.

Biology. Due to confusion with A. natlovei , a reexamination of host records reported in the literature for A. conoidea is warranted. Burke (1918) reports rearing A. conoidea from dead flower stalks of sotol, Dasylirion wheeleri S. Watson ( Liliaceae ), a record repeated in Chamberlin (1926) but using the common name Spanish dagger in error. Burke’s host record was thought to be based on a misidentification until recently, when A. conoidea was reared from a sotol stalk in Arizona, confirming the larval host record: Arizona, Santa Cruz Co., Ruby Rd., Atascosa Trailhead, elev. 4701′, 12R 486024 3474474 UTM, ex Dasylirion wheeleri coll. 20.iv.2018, em. viii.17–ix.14.2019, P. Kaufman [POKC]. Larval host records of A. conoidea from Ulmus crassifolia Nutt. ( Ulmaceae ), Juglans sp. , and Celtis laevigata var. reticulata are also in question ( Westcott et al. 1979; MacRae and Nelson 2003). The record from U. crassifolia in south Texas was found to be based on a misidentified specimen of A. neoneglecta , a common species in the Texas Rio Grande Valley (Ted MacRae, pers. comm.). Unfortunately, the previously reported specimen of A. conoidea reared from Juglans sp. (Westcott et. al. 1979) could not be examined. Considering misidentification of A. natlovei specimens was common at the time for the previously stated reasons and the timing of its emergence (i.e., May), it is highly likely the specimen represents A. natlovei . Further supporting evidence was the discovery of a dead A. natlovei adult in its pupal chamber within a dead branch of Juglans macrocarpa , in Ft. Davis, Texas (personal observation). The solitary specimen of A. conoidea reared from C. laevigata var. reticulata ( MacRae and Nelson 2003) was examined by the author and determined to also represent A. natlovei . During the preparation of this manuscript, additional specimens came to light, also reared from Celtis sp. collected in Eddy Co., New Mexico near Carlsbad, as noted above in Materials Examined.

Figures

Figure 3. Acmaeodera conoidea Fall, paralectotype ♂. a) Dorsal view. b) Ventral view. c) Lateral view. d) Broadly arcuate clypeus e) Third stria split near umbone. f) Protarsal claw.