Iphthiminus serratus ( Mannerheim 1843 )

Gardiner, Rebekka M. & Pollock, Darren A., 2015, Revision of the Nearctic species of the genus Iphthiminus Spilman (Coleoptera: Tenebrionidae), Zootaxa 4048 (3), pp. 352-391 : 356-360

Iphthiminus serratus ( Mannerheim 1843)

( Figs. 1 , 2 , 3 ; Appendix 1)

Nyctobates serratus Mannerheim 1843: 284 [Type area: in “California ad St. Franzisco.” Type repository: MZH (Helsinki)]; LeConte 1866b: 61.

Iphthimus serratus: Truqui 1857: 94 ; LeConte 1866b: 61; Horn 1874: 34 –35; Wickham 1890: 87, 239; Bertkau & Hilgendor 1891: 301; Fall 1894: 101; Knauss 1903: 177; Casey 1924: 328, St. George 1925: 8, 21; Gebien 1941: 339; Leng et al. 1920: 235; Parsons et al. 1991: 62.

Nyctobates sublaevis Bland 1865: 382 [No locality listed in description, but later listed as collected in Colorado ( Horn, 1870). Type Repository MCZ]; LeConte 1866b: 61.

Iphthimus serratus serratus Horn 1870: 334 .

Iphthimus serratus sublaevis Horn 1870: 334 ; Fall, 1901: 31.

Iphthimus sublaevis: LeConte 1866b: 61 ; Carpenter 1875: 569; Wickham 1890: 87; Griffith 1900: 569; Wickham 1898, 310; Snow 1904: 334; Gebien 1941: 339; Leng et al. 1920: 235; St. George 1925: 21; Hayward 1948: 482, 504. New synonymy.

Iphthimus salebrosus Casey 1924: 327 [Type area: California. Type repository USNM] New synonymy.

Iphthinus servilis Walker in Lord 1866: 311, 326 [Type area: Vancouver Island. Type repository BMNH, type (s) not examined]; LeConte 1870: 401; Blair 1921: 282.

Iphthinus servator Walker in Lord 1866: 311, 327 [Type area: Vancouver Island. Type repository BMNH, type (s) not examined]; LeConte 1870: 401; Blair 1921: 282.

Iphthinus subligatus Walker in Lord 1866: 311, 327 [Type area: Vancouver Island. Type repository BMNH, type (s) not examined]; LeConte 1870: 401; Blair 1921: 282.

Iphthiminus serratus : Poole and Gentili 1996: 437; Bousquet 1991: 261.

Iphthiminus salebrosus : Poole and Gentili 1996: 437; Bousquet 1991: 261. Iphthiminus sublaevis : Poole and Gentili 1996: 437.

Notes about type material ( I. serratus ). As there is no range of measurements mentioned in the original species description ( Mannerheim 1843), it is likely that the specimen herein identified as the holotype was the only specimen on which the description was based. The female holotype has the following information: [handwritten det. Label] “Female symbol”/ “Eschsch.”/ [handwritten det. Label] “California.”/ [handwritten det. Label] “Sub nomine Upis serricollis missus”/ “Mus. Zool. Helsinki Loan Nr. C 06-39”. The type has the following features: right middle leg reglued, right back leg missing, underside of specimen dirty. “Eschsch” is a reference to Dr. J. F. Eschscholtz, who worked with Gustav von Mannerheim, known for collecting specimens on trips to the United States and returning them to Europe for description ( Dow 1914).

Notes about type material ( I. sublaevis ). One specimen of undetermined gender is the type of this species ( Bland, 1865). As there is no range of measurements mentioned in the original species description, it is likely this is the only specimen upon which the species is based. The holotype has the following information: possibly white dot, covered in detritus; any information written on the dot is illegible. / “ TYPE 7205”/ [handwritten det. Label] “ N. sublaevis ! Bland.”/” Jan-Jul 2005 MCZ Image Database.” The type has the following characteristics: right antenna with only two basal segments. Elytra open posteriorly, sternite extended.

Notes about type material ( I. salebrosus ). One specimen of undetermined gender is the type for this species. The holotype has the following labels: “Metla, B. Col”/ “ CASEY bequest 1925”/ TYPE USNM 46766”/ [handwritten det. Label] ‘ salebrosus Casey ”. The holotype has the following features: small pinhole through right elytron, elytra separated, open posteriorly, right hind leg absent.

Taxonomic notes. Due to the particularly short descriptions, determining distinguishing characteristics for I. sublaevis ( Bland 1865) and I. serratus ( Manerheim 1843) was difficult. The I. serratus description notes the elytra as being lightly sequentially punctured ( Mannerheim 1843: 284), while the I. sublaevis description notes the striae as being obsolete, nine rows of punctures that are not deep ( Bland 1865: 382). Examination of type specimens revealed little difference in the striations of the types of these two species; the punctures are slightly deeper in the I. serratus type than that of I. sublaevis . Later, Horn (1870) described differences between the species as a degree of punctation, in which I. serratus was considered to be a more rugose and heavily punctate form and I. sublaevis was considered to be have a smoother pronotum, elytra and underside. Horn (1870: 334) also considered I. sublaevis and I. salebrosus to be subspecies of I. serratus . As these characters are highly variable, and change gradually across range from heavily punctate and rugose in the northern limit of the range (British Columbia) to smoother, less deeply punctate in the southernmost limit of the range (southern California) with intermediate forms in the middle range, they are considered to be variation within a species, not indicators of separate species. Therefore, I. sublaevis is considered to be a synonym of I. serratus .

Though Casey (1924: 328) stated that there were many “radical differences” between I. salebrosus , I. sublaevis and I. serratus , the only one character he specified was that the pronotum was larger and broader in I. salebrosus . The type specimen used for this description is large, but atypically so. Other non-type specimens that show the particular traits of this species as Casey described them are smaller in size. As he based this description on the single large specimen, this difference is not considered to be important. Proportions used in the description are based upon this one specimen, and examination of non-type specimens has shown proportions to be variable, along with serrations on the lateral edges of the pronotum, which limits the usefulness of these features as distinguishing characteristics. The I. salebrosus description ( Casey 1924) notes the striae as being coarse and deep, sometimes forming lines, with several lines running almost the entire length of the elytra. However, comparison of this type to other specimens found in the same locality has shown this specimen to be atypical. The strial punctures that form lines are seen in a few of the specimens, but not to the degree seen in the type. Examination of non-type specimens showed that striae are highly variable, and are deeper on specimens from more northern parts of the geographical range of the species. As striae are a highly variable character that show a gradual change over geographical range, I. salebrosus is hereby considered to be a synonym of I. serratus .

Walker in Lord (1866) described three new species (in Iphthinus ) from Vancouver Island. All three were the same length (11 lines), and differed slightly from one another by characters of the pronotum and elytral punctation; no mention was made of the previously described I. serratus Mannerheim. LeConte (1870: 401) stated that I. servilis represents the “typical form” of I. serratus , and that I. servator “does not differ in any important respect”. The specimen of I. subligatus was thought to be a more “finely striate race” of I. serratus ( LeConte 1870: 401) . Blair (1921: 282) also commented on these three specimens, and stated that the type specimen of I. servator is “an abnormal individual with the sides of the prothorax somewhat up-turned in front”. Blair also mentioned that the depth of the strial elytral punctures varies among the three Walker type specimens.

Description. With general features of Iphthiminus , and the following characteristics: GHW 2.9–4.4 mm.; GPW 3.2–5.8 mm; GEW 6.3–10.7 mm; HL 3.2–5.8 mm; PL 3.4–5.4 mm; EL 11–16.8 mm; TL 17.7–27.5 mm; ratio of HL/HL 0.71–1.1; PW/PL 0.89–1.8; GEW/EL 0.49–0.87; HW/PW 0.49–0.87; HL/PL 0.71–1.16; PL/EL 0.26–0.41; TL/GEW 2.44–3.14; GEW/EL 1.49–1.98; PW/GEW 0.47–0.93. Pronotal punctation coarse, distinct, lateral edges of pronotum moderately serrate; elytral striae coarse, some overlapping to form ‘dashes’; interstices flat.

Diagnosis. Specimens of I. serratus ( Fig. 1 ) are diagnosed on the basis of the following characteristics: Pronotum with large, uniform punctures, interstices of elytra flat, interstitial punctures of elytra numerous and distinct, paramere apex slightly flared ( Fig. 2 ).

Distribution. Based on examined specimens, the geographic range ( Fig. 3 ) of this species is as follows, organized by county (detailed locality list in Appendix 1): UNITED STATES OF AMERICA. California: Alameda (7), Alpine (23), Amador (2), Butte (3), Calaveras (25), Colusa (1), Del Norte (5), El Dorado (140), Fresno (40), Glenn (20), Humboldt (24), Inyo (6), Kern (22), Lake (10), Lassen (18), Los Angeles (3), Madera (23), Mariposa (48), Mendocino (41), Merced (1), Modoc (35), Mono (9), Monterey (1), Napa (1), Nevada (57), Placer (39), Plumas (145), Riverside (1), San Bernardino (1), San Diego County (1), San Francisco (2), Santa Clara (9), Santa Cruz (3), Shasta (78), Sierra (24), Siskiyou (87), Sonoma (19), Tehama (7), Trinity (52), Tulare (69), Tuolumne (146), Yolo (2), Yuba (1), Unknown (144). Idaho: Ada (2), Adams (1), Benewah (1), Boise (3), Bonner (20), Boundary (6), Camas (1), Cassia (9), Clearwater (4), Elmore (2), Fremont (3), Idaho (1), Kootenai (33), Latah (44), Lemhi (1), Lewis (1), Nez Perce (1), Shoshone (14), Twin Falls (7), Valley (7), Unknown (7). Montana: Flathead (6), Lake (3), Lewis and Clark (4), Lincoln (4), Missoula (4), Powell (1), Ravalli (2), Stillwater (1), Unknown (7). Nebraska: Grant (1). Nevada: Douglas (4), Elko (1), Washoe (3), Unknown (3). New Mexico: Doña Ana (1). Oregon: Baker (25), Benton (16), Clackamas (15), Clatsop (3), Columbia (5), Coos (1), Crook (1), Curry (1), Deschutes (23), Douglas (5), Grant (22), Hood River (6), Jackson (25), Jefferson (7), Klamath (47), Lake (8), Lane (8), Lincoln (4), Linn (8), Marion (1), Morrow (5), Multnomah (5), Tillamook (1), Umatilla (16), Union (3), Wasco (9), Washington (4), Wheeler (1), Yamhill (2), Unknown (35). Washington: Asotin (7), Benton (2), Chelan (2), Clallam (4), Franklin (1), Grays Harbor (18), King (9), Kitsap (6), Kittitas (3), Klickitat (2), Mason (1), Pend Oreille (11), Pierce (32), San Juan (6), Skagit (7), Skamania (1), Snohomish (2), Spokane (10), Thurston (10), Walla Walla (1), Whitman (17), Yakima (9), Unknown (24). Wyoming: Teton (2), Unknown (7). CANADA. Alberta (1). British Columbia (246).

Figures

FIGURE 1. Iphthiminus serratus, dorsal habitus. Winema National Forest, Klamath Co., Oregon.

FIGURE 2. Male genitalia of I. serratus. A. Dorsal view. B. Lateral view. Scale bar = 1 mm.

FIGURE 3. Distribution of I. serratus. Circles indicate specific localities, while squares indicate county-only localities. Canadian provinces (NOAA 1999) and US counties (NOAA 2014) are shown as outlines.