Anorus parvicollis Horn, 1894

Johnston, M. Andrew & Gimmel, Matthew L., 2020, Review of North American Dascillidae (Coleoptera: Dascilloidea), with Descriptions of Dramatic Female Wing Reduction, The Coleopterists Bulletin 74 (4), pp. 731-757 : 732-736

Anorus parvicollis Horn, 1894

( Figs. 1–3 )

Anorus parvicollis Horn 1894: 365 . Type locality: Near Fort Yuma , Yuma County, Arizona.

Anorus arizonicus Blaisdell 1934:323 .New synonym. Type locality: Cave Creek, Mariposa [sic; Maricopa] County , Arizona.

Diagnosis. Males of this species ( Figs. 1 , 2 ) are readily separated from Dascillus by the prosternal process forming a short denticle near the anterior coxal margin, resulting in the procoxal cavities being contiguous externally (prosternal process completely separating procoxae in Dascillus). From Anorus piceus it may be separated by the sparse, long, mostly erect setae present throughout the dorsal surface and general lack of short decumbent undersetae (A. piceus with dense, recumbent setae dorsally). The scutellar shield is totally devoid of setae (setose in A. piceus). The pronotum is narrower overall than that of A. piceus, with the width across the anterior angles being roughly equivalent to the width across the posterior angles, and the greatest width of the pronotum is at about the midpoint (A. piceus pronotum wider at posterior margin than anterior margin). The elytron does not possess a sulcus along the lateral margin as in A. piceus and Dascillus. The mandibles are less protruding in this species than A. piceus, and the incisor edge possesses three retinacula before the apex and is not longitudinally straight. Females ( Fig. 3 ) are easily recognized by the disposition of the elytra, which are scale-like and do not extend much beyond the scutellar shield.

Redescription of Male. Body slender and nearly parallel-sided, 6–12 mm ( Fig. 1 ). Body setae long, thin, bristling. Antennomeres 3–10 very weakly serrate, at least 2 times longer than wide. Left mandible always with two retinacula at midlength of mandible and weak basal retinaculum variably developed. Right mandible similar to left. Epicranial suture not discernible externally. Lateral sides of pronotum not explanate, lateral carina usually indistinct anteriorly, posterior margin straight to weakly bisinuate; pronotum widest near middle, anterior and posterior widths subequal. Hypomeron entirely lacking postcoxal process. Prosternal process forming short denticle (as in Fig. 3B ), barely surpassing anterior margin of procoxae, lacking thin lamina between procoxae; mesoventrite lacking prosternal and procoxal rests entirely. Elytra attaining apex of abdomen; punctation variable, generally with scattered punctures; striae not or extremely weakly impressed. Hind wing attaining apex of abdomen; radial cell widely open proximally; wedge cell small, separated from posterior edge by distance greater than length of cell; apical field about one-third length of wing. All tibiae bearing stout spinules along outer margin. All legs with tarsomeres 1–4 bearing small fleshy pads beneath, 1–2 with smaller pads, not clearly bilobed, 3–4 with larger pads, distinctly bilobed. Terminalia with tergite IX ( Figs. 2C, F ) with broad V-shaped emargination along posterior margin; tergite X ( Figs. 2C, F ) evenly rounded to subtruncate apically; sternite IX ( Figs. 2B, E ) rounded apically; phallobase of aedeagus ( Figs. 2A, D, G–J ) distinctly emarginate basally, slightly broader than long; parameres longer than phallobase, very gradually narrowing from base to apex, lateral margin slightly convex, not at all recurved apically, bearing short setae ventromedially in apical half; dorsal lobe of penis measured from anterior margin of basal strut to posterior apex approximately as long as paramere, gradually tapering, apex evenly rounded, never appearing cleft; ventral lobe of penis approximately two-thirds length of dorsal lobe, clawlike, evenly curved ventrally to sharply pointed apex.

Description of Female. Body stout ( Figs. 3A, B ). Head globose, eye small, subequal to size of second antennomere. Frons smooth and glabrous, temples and occiput rugosely punctate and sculptured, densely covered with long setae. Mandibles stout, well sclerotized, with acute retinaculum preapically on dorsal cutting surface, left mandible with additional small tooth more apically, ventral cutting surface of both with basally positioned, obtuse lobe. Labrum weakly bilobed. Pronotum highly transverse, 2.5 times wider than long, anterior margin strongly and posterior margin weakly bisinuate, pronotum appearing evenly arcuate laterally but lateral carina absent. Scutellar shield transverse, devoid of setae. Elytron weakly sclerotized, shorter than pronotum, transverse, trapezium-shaped, elytra not in contact medially and separated by scutellar shield. Hind wing absent. Abdominal sternite IX distinctly sclerotized, contrasting with previous segments. Terminalia ( Figs. 3C, D ) with tergite IX not observed, seemingly weakly sclerotized; sternite VIII (spiculum ventrale) appearing narrowly emarginate, without anterior strut or lobe; proctiger not observed; paraprocts very short, with ventral baculi converging apically; gonocoxites distinctly longer than paraprocts, each coxite with longitudinal baculum with basal thickening; gonostyli present, palpiform.

Note on Synonymy and Type Material. Although male specimen series from particular localities seem to be consistent in morphological detail, from the specimens we have examined there is no apparent clinal variation or line of demarcation in width vs. length, pronotal shape (the primary character in the original diagnosis of A. arizonicus ) or coloration in males ( Fig. 1 ). Blaisdell (1934) made the comment that “Arizonicus is a very distinct species,” but he only examined the type series of five males and apparently only observed two males of what he considered to be A. parvicollis, those being the type and an additional specimen in CASC from Phoenix, Arizona. Additionally, no significant differences were observed among male genitalia ( Fig. 2 ), which are shown here to be distinct from other known species in the family. Clearly a twospecies system representing this complex of populations is a misleading arrangement.

Horn (1894) did not mention the number of specimens he used for his original description of A. parvicollis. Examination of the Horn collection (MCZ) revealed 10 male specimens, one labeled “ lectotype ” and the remainder each labeled “ paratype ”. All should be considered syntypes. Two additional male specimens in the LeConte collection (MCZ) are probably syntypes. The holotype of A. arizonicus is a male deposited in CASC (type no. 3735). Four male paratypes are also present in CASC, bearing the same data.

Distribution. Throughout the low desert areas of Arizona, south into Sonora (and possibly Sinaloa), Mexico ( Fig. 4 ). The records from California and Nevada represent new state records for this species. Previous records of this species from Baja California, Mexico, are quite possibly in error, since we have seen no specimen vouchers. However, if A. parvicollis is present in Baja California, they may be expected to occur in the lower Colorado Desert in the northeastern portion of the state. The specimens putatively from Sinaloa were intercepted at the United States border within produce shipments that originated from Sinaloa and subsequently transported through this species’ range in Sonora.

Specimens Examined (215). UNITED STATES: ARIZONA: La Paz Co.: 1 mile northwest of Bouse , 1 June 1946, J. R. Slevin ( 2♂♂, CASC); 6 miles southeast of Parker , 7 May 1966, Gorodenski, Davidson and Cazier ( 1♂, ASUHIC); Maricopa Co. : 5 miles east of Mesa , 30 May 1964, S. A. Gorodenski ( 2♂♂, ASUHIC); 5 miles west of Wickenburg, 2,4700 elevation, 5 June 1978, C. Bellamy ( 1♂, LACM); Bush highway junction with Usery Pass road, 23 April 1981, W. B. Warner ( 1♂, ASUHIC); Sunflower, J. McCormick ( 1♂, ASUHIC); Salt River at Blue Point Forest Campground, 27 April 1974, Rockwood, Draper and Kolner ( 3♂♂, ASUHIC); Thunderbird Regional Mountain Park, 23 May 1975, R. S. Wielgus and F. F. Hasbrouck ( 12♂♂, ASUHIC); Wickenburg, 16 May 1937, E. Van Dyke ( 2♂♂, CASC); Wickenburg, 11 May 1938, L. M. Martin ( 5♂♂, LACM); Wickenburg, 1 June 1959, L. A. Stange ( 4♂♂, LACM); Mohave Co.: Lower Boner Canyon , 34.7431° 113.5903°, 15 April–24 June 2017, Barrier Pitfall Trap, M. A. Johnston ( 3♂♂, MAJC); Pima Co. : 8 km E of Robles Junction, Avra Valley , 32° 040 N 111° 150 W, 14–24 April 1996, UV light, D. Yanega ( 3♂♂, INHS); Ajo, 25 April 1935, F. H. Parker ( 3♂♂, UCRC); Baboquivari Canyon, 9 April 1963, Timberlake ( 2♂♂, UCRC); Santa Catalina Mountains, 8 May 1933, Bryant ( 1♂, CASC); Tucson, 16 May 1937, Bryant ( 4♂♂, CASC); Tucson, 14 May 1940, L. M. Martin ( 10♂♂, LACM); Tucson, 31 May 1956, J. L. Van Deren ( 1♀, UAIC); same except found in a new house, laid eggs ( 1♀, UAIC); Tucson, 5 May 1998, R. L. Otto ( 4♂♂, UAIC); Vail, Mountain Creek Ranch , 32° 04.990 N, 110° 39.560 W, 1,100 m, 2–9 May 2006, Malaise trap in dry wash, M. E. Irwin ( 1♂, SBMNH); Sonoran Desert Museum , 21 April 1961 ( 1♂, SBMNH); Pinal Co. : 10 miles south of Florence , 32.902° 111.281°, 25 April 2015, M. A. Johnston ( 40♂♂, MAJC); same except M. Gimmel and L. Indruchová ( 27♂♂, ASUHIC); same except Gimmel , Johnston and Anzaldo ( 22♂♂, MAJC); Yuma Co. : Aztec , 16 April 1954 ( 4♂♂, LACM); Dateland , 32° 4704200 N 113° 3202600 W, 15 February–5 May 2011, W. B. Warner ( 1♂, MAJC; 1♀ imaged by William B. Warner, deposited in the Albert Allen Collection of Coleoptera in Star , Idaho ); Mohawk , 14 April 1963, Timberlake ( 1♂, UCRC); Yuma , 27 March 1971, J. Kirkpatrick ( 4♂♂, ASUHIC). CALIFORNIA: Riverside Co. : 18 miles west of Blythe , 29 April 1952, Timberlake ( 2♂♂, UCRC); Chuckwalla Road 2 miles east of junction with highway 10, 12 April 1986, J. Rifkind and P. Gum ( 1♂, LACM); Cottonwood Mountains 25 miles east of Indio , 1,8000 elevation, 18 April 1986, J. P. and K. E. S. Donahue ( 4♂♂, LACM); Pinto Wells at Joshua Tree National Monument , 28 April 1962, E. L. Sleeper ( 1♂, CASC); San Bernardino Co. : 44 km S of Needles, 34.4388°N, 114.6517°W, 28 April–4 May 2007, Malaise trap in dry wash with flowering Cercidium, M. E. Irwin ( 4♂♂, SBMNH). NEVADA: Clark Co. : Nellis Dunes northeast of Las Vegas , 36° 1703000 N 114° 5704900 W, 11 June 2010, W. E. Steiner, J. M. Swearingen ( 2♂♂, USNM). MEXICO: SINALOA: intercepted at Nogales , Arizona , on tomato fruit from Culiacán , 24 April 1939 ( 1♂, USNM); intercepted at Nogales , Arizona , on tomato wrapper from San Blas , 12 May 1932, E. C. Harrison ( 1♂, USNM) [these two interception records not included in map]; SONORA: 16 miles south of Hermosillo , 16 February 1963, P. H. Arnaud ( 7♂♂, CASC); 4 miles north of Navojoa , 30 March 1961, K. D. Payton ( 6♂♂, UCRC); Bahia Cholla , 12 April 1954, Menke and Stange ( 1♂, LACM); Keno Bay [= Bahia Kino], 4 April 1953, M. C. Cushner ( 6♂♂, CASC); Puerto Pe ~ nasco, 16 May 1972, Dr Lenczy ( 7♂♂, USNM); San Pedro Bay , 3 April 1953, P. H. Arnaud ( 2♂♂, CASC). Doubtful locality, not mapped: CALIFORNIA: Orange Co. : Seal Beach , 16 May 1938, D. Poole ( 2♂♂, LACM).

Figures

Fig. 1. Anorus parvicollis, male habitus showing variation. A) Specimen from Florence, AZ showing typical “parvicollis form,” B) Specimen from Parker, AZ showing slightly angulate pronotal margin, C) Specimen from Glendale, AZ showing typical “arizonicus form” pronotal shape with light-colored body, D) Holotype of A. arizonicus from Cave Creek, AZ showing angulate posterior pronotal angles and darker body color (image credit: Rachel Diaz-Bastin).

Fig. 2. Anorus parvicollis, male terminalia. A, D, H–J) Aedeagus, ventral view, B, E) Genital capsule, ventral view showing sternite IX, C, F) Genital capsule, dorsal view showing tergites IX–X, G) Aedeagus, oblique ventral view. A–C) Dissected specimen from “Seal Beach, CA” [data probably in error], D–G) Dissected specimen from Salt River, Mesa, AZ, H) Dissected specimen from Yuma, AZ, I) Dissected specimen from Florence, AZ, J) Dissected specimen from Navojoa, Sonora, Mexico.

Fig. 3. Anorus parvicollis female. A) Dorsal habitus of a specimen from Dateland, AZ (image credit: William B. Warner), B) Head and thorax, ventral view of cleared specimen from Tucson, AZ. C–D) Abdominal apex of cleared specimen from Tucson, AZ: C) Ventral view, D) Dorsal view.

Fig. 4. Distribution map for Anorus parvicollis.