Panscopus (Nocheles) squamifrons Pierce, 1913

Spanton, Timothy G. & Anderson, Robert S., 2016, A Taxonomic Revision of Weevils of the Genus Panscopus Schönherr (Coleoptera: Curculionidae: Entiminae: Tropiphorini), The Coleopterists Bulletin (mo 15) 70, pp. 1-86 : 60-61

Panscopus (Nocheles) squamifrons Pierce, 1913

( Figs. 24 , 50 , 72 , Map 25 )

Panscopus (Neopanscopus) squamifrons Pierce 1913: 397 . Buchanan 1927: 29, 1936: 13; Schenkling and Marshall 1931: 41; Blackwelder 1939: 66.

Panscopus (Neopanscopus) wickhami Buchanan 1936: 13 . Blackwelder 1939: 66. New synonymy.

Panscopus squamifrons ; O’ Brien and Wibmer 1982: 63.

Panscopus wickhami ; O’ Brien and Wibmer 1982: 63.

Type Material. Holotype female: “Placer/ Co. Cal.; June; Through / C. V. Riley; TYPE / No. 14644/ U.S. N.M.; Panscopus / squamifrons / Type Pierce”. The holotype of Buchanan’ s (1936) P. wickhami , bearing the following label data, was also examined: “Truckee Cal. Aug.. 5800 ft. Wickham ; Wickham Collection 1933; Panscopus (Neopanscopus) wickhami / male TYPE Buch.”

Notes about Synonymy. The holotypes of P. squamifrons and P. wickhami are clearly conspecific. Buchanan (1936) based his description of P. wickhami on a very small male. The characters he cites (elytral intervals subplanate, setae short and inconspicuous, and the prothorax as long as wide) are all found within the range of individual variation among specimens in several population samples of this taxon. No external characters or genitalic characters suggest a reason for recognizing two species.

Specific Epithet. From the Latin nouns “ squama”, scale, and “ frons”, brow, or face, referring to the scale-covered frons which is typical of this and other species of Panscopus .

Diagnosis. The combination of all elytral intervals equally convex, alternate intervals not raised above even intervals, and thin, semi-erect, narrow setae in rows on all elytral intervals separates specimens of P. aequalis and P. squamifrons from those of other species in the subgenus Nocheles . Specimens of P. squamifrons are distinguished by their very dense scale covering and smooth pronotal surface, in contrast to the coarsely rugose pronotal surface exhibited by adults of P. aequalis .

Redescription. Females: Length 5.2–6.0 mm (n = 7); width across elytra 2.2–2.6 mm (n = 7). Males: Length 5.6–6.3 mm (n = 8); width across elytra 2.1–2.3 mm (n = 8). Color: Grey-brown overall. Under magnification, irregular patches of pale grey scales and areas of brown scales. Head: Transverse impression at base of frons slight; frons and rostrum nearly continuous in lateral view; vestiture of frons and rostrum of dense, overlapping grey scales, and decumbent, stout, blunt setae; nasal plate indistinct; nasal carina obvious, broadly curved, more U-shaped than V-shaped. Antennae: Scape short, extending to middle of eye, with very dense vestiture of scales and coarse setae, integument obscured over most of length. Pronotum: Nearly as long as wide; width only 4% greater than length in males; in females, proportionately wider, width approximately 10% greater than length; median longitudinal sulcus absent to very slightly developed anteriorly, dorsal surface smooth; vestiture of dense, overlapping grey and brown scales and scattered, decumbent setae. Elytra: Broadly oval in dorsal view, combined width approximately 72% of length, and approximately 42% wider than pronotum in females; proportionately narrower in males, combined width 68% of length on average, and 40% wide than pronotum; declivity continuously rounded to reflexed apex; all elytral intervals equally slightly convex, each interval with complete row or partially double row of semi-erect, fine, acute setae; serial punctures each with scale, scales of serial punctures oval, in some slightly angular apically; elsewhere with dense vestiture of pale grey scales or with patches of beige, overlapping, striate scales. Legs: Tibiae 1, 2, and 3 with row of stout spines on ventral edge in distal 1/3, more pronounced on tibiae 1 and 2; tibia 3 very slightly bent; corbellar area narrowly and indistinctly closed. Abdomen: Ventrite 1 of females slightly convex at middle; ventrite 1 of males concave at middle; ventrites 1–5 with vestiture of grey and brown scales similar to those on dorsum. Genitalia: Females ( Figs 24 , 50 ): Sternum VIII (spiculum ventrale) with apical expansion approximately 1/3 its length; coxites angular in dorsal view; vagina membranous, with pair of crescent-shaped sclerites near confluence with common oviduct; spermatheca sickle-shaped, broad, tapering toward apex in distal half. Males ( Fig. 72 ): Median lobe of aedeagus short, decurved,; apex broadly rounded; manubrium of tegmen about as long as median lobe; median struts slightly longer than median lobe; internal sac membranous, without fields of visible denticles; with 1 large horseshoeshaped sclerite and small v-shaped sclerite within it, both near apex of sac (located anteriorly to belt of tegmen in inverted sac).

Life History. Label data indicate that adult specimens have been collected in April through August. More specimens were collected in June and July than in other months of the year.

Plant Associations. Plant names associated with specimens of P. wickhami are 22 specimens taken from Artemisia litter, one specimen taken from Symphoricarpos sp. , probably S. vaccinioides , and one specimen collected under Jeffrey pine ( Pinus jeffreyi Balf. ).

Geographical Distribution. This species lives in the central Sierra Nevada of eastern California, north to the Cascade Mountains of southern Oregon, and east to Nevada ( Map 25 ). Records range from elevations of 1,680 to 2,650 m .

Chorological Affinities. See this topic for P. aequalis above.

Material Examined. In addition to the type material listed above, approximately 225 specimens were examined. USA: California: Alpine Co., Lake Alpine , 26.VI.1935, R.P. Allen (1, CASC) ; Jul-34, W.H. Nutting (1, CNCI) . Amador Co., Pioneer , 45 km N.E. 2260 m, 18.VII.1966, L. & C.W. O’ Brien (1, CNCI) ; Pioneer , 45 km. N.E., 8.VII.1966, L. & C.W. O’ Brien, at night (1, CWOB) ; El Dorado Co., Angora, Lake Tahoe , 22.VI.1915, Van Dyke collection (1, CASC) ; Bijou, Lake Tahoe , 27.VI.1929, E.P. Van Duzee (1, CASC) ; Tallac , VIII., Blaisdell collection (1, CASC) ; Tallac , 3.VII.1898, A. Fenyes collection (2, CASC) ; El Dorado Co., Van Dyke collection (1, CASC) ; Fallen Leaf Lake, Lake Tahoe , 12.VII.1915, Van Dyke collection (1, CASC) ; Lake Tahoe , 19.VI.1936, L.H. Rich (1, USNM) . Lassen Co., Facht , 27.V.1919, J.O. Martin (26, CASC) ; Facht , 27.V.1922, J.O. Martin, (30, CASC; 1, CMNC) ; Facht , 20.V.1922, J.O. Martin (11, CASC) ; Facht , 20.VI.1922, J.O. Martin (1, CASC) ; Norval Flats 1680 m, 12.VII.1920 (2, CASC) ; Norval Flats 1680 m, 12.VII.1920, J.O. Martin (8, CASC) ; Mono Co., Bodie 2580-m, Wickham (1, USNM) ; Bridgeport , 12 km W. 2100 m, 6.VII.1966, C.W. O’ Brien (1, AMNH; 7, CWOB; 1, FMNH; 1, OSUC) . 5.5 km E. Sonora Pass Summit , 2650 m, 23/24.vi.1986, T.G. Spanton, lodgepole forest (2, CMNC) . Nevada Co., Boca , 3.VII.1954, R.C. Blaylock (1, UCDC) ; Boca , 3. VII.1954, R.H. Goodwin (1, CWOB) ; Boca , 3. V.1954, J.A. Powell (1, CWOB) ; nr. Hobart Mills , 23.VI.1962, R.L. Westcott (6, LACM) ; Prosser Ck. 1 mi. S Hobart Mills 1770 m, 18.VI.1966, C.W. O’ Brien, at night (1, CMNC; 15, CWOB) ; Prosser Ck , 1.6 km W. Hobart Mills 1770 m, 18.VI.1966, W. Gagne, at night (3, CWOB) ; Prosser Creek, 1.6 km W. Hobart Mills 1800 m, 17.VII.1965, E.L. Smith (1, CWOB) ; Sagehen Creek , 21.VI.1978, L.D. French (1, UCDC) ; Sagehen nr. Hobart Mills , C.A. Toschi (1, CNCI; 3, CWOB) ; Upper Sagehen Creek , 5.VII.1962, J. Powell (1, CWOB) . Placer Co., Truckee , 17.VI.1927, E. P. Van Duzee (4, CASC) ; Truckee , 30.V.1946, A.T. McClay collection (13, UCDC) ; Truckee , 30.VI.1946, A.T. McClay (13, UCDC) ; Nyack , 5.VI.1978, W.F. Barr (1, CMNC) . Sierra Co., Sierraville , 5 km S, 18.VI.1966, C.W. O’ Brien, at night (2, CWOB) ; Sierraville , 8 km S., 18.VI.1966, W. Gagne, C.W. O’ Brien, at night (1, BMNH; 1, CNCI; 2, CMNC; 12, CWOB) ; Webber Lake , 4 mi. E, 19.VII.1939, W. F. Barr (2, USNM) ; Webber Lake , 3 mi E, 19.VII.1939, W.F. Barr (64, UICM) . Nevada: Douglas Co., Spooner Summit hwy 50, 2130 m, 13.VII.1958, F. Raney, under Jeffrey pine (1, CWOB) . Washoe Co., Mt. Rose , 9.VII.1964, D.F. Veirs (1, CWOB) . Oregon: Harney Co., Lilly Lake, Steens Mountains , Summit Rd. 24 km E of Frenchglen, 29.VII.1971, Benedict, leaf litter (1, CMNC) ; Steens Mountains, Fish Lake , 15.VII.1962, J. Baker (1, USNM) . Klamath Co., Algoma, Upper Klamath Lake , 11.IV.1962, J. Schuh, Artemisia litter (12, AMNH; 5, FMNH; 6, OSAC) . Union Co.: N. Powder , 8.VI.1924 (2, USNM) .

Figures

Map 25. Geographical distribution of Panscopus squamifrons.

Figs. 17–26. Panscopus species, sternum 8 (spiculum ventrale), ventral (a) and left lateral (b) views. 17) P. torpidus; 18) P. ovalis; 19) P. tricarinatus; 20) P. bufo; 21) P. schwarzi; 22) P. coloradensis; 23) P. aequalis; 24) P. squamifrons; 25) P. abruptus; 26) P. rugicollis. Scale bar = 1 mm.

Figs. 47–52. Panscopus species, coxites and vagina, dorsal (a), ventral (b), and left lateral (c) views. 47) P. schwarzi; 48) P. coloradensis; 49) P. aequalis; 50) P. squamifrons; 51) P. abruptus; 52) P. rugicollis. cx = coxites; st = stylus. Scale bar = 1 mm.

Figs. 71–73. Panscopus species, aedeagus, dorsal (a), ventral (b), and left lateral (c) views. 71) P. coloradensis; 72) P. squamifrons; 73) P. abruptus. b = belt of tegmen; is = internal sac; mb = manubrium of tegmen; ml = median lobe; ms = median strut; t = tegmen. Scale bar = 1 mm.