Ellescus californicus (Casey, 1885)

Lewis, Jake H. & Anderson, Robert S., 2023, A review of EllESCUS (Coleoptera: Curculionidae) in North America: new species and synonyms revealed through integrative taxonomy, The Canadian Entomologist (e 15) 155 (2023), pp. 1-27 : 12-14

Ellescus californicus (Casey, 1885) , resurrected status

Figs. 5C , 6C , 7 Elleschus californicus Casey, 1885 (original description). Elleschus ephippiatus var. californicus ; O’ Brien and Wibmer 1982: 116 (catalogue, distribution). Elleschus ephippiatus ; Poole and Gentili 1996: 215 (catalogue).

Notes about the type series. This species was described from two specimens collected in California, United States of America. The holotype ( USNM) is labelled with one brown rectangular label that reads “Cal.”, a second brown rectangular label that reads “californicus type. Casey.”, a third brown rectangular label that reads “CASEY bequest 1925”, a red rectangular label that reads “TYPE USNM 36721”, and an institutional ID label that reads “USNMENT 01448984” .

Specimens examined

Holotype. UNITED STATES OF AMERICA: California: Casey (1, USNM), CASEY bequest 1925, TYPE USNM 36721, USNMENT 01448984.

Other material. UNITED STATES OF AMERICA: California: Sutter Co., Nicolaus , 18.iv.1971, Fred G. Andrews (1, CMNC) ; San Bernardino Co., Needles , 8.iv.1989, W.F. Barr, on willow (2, CMNC) ; San Bernardino Co., Victorville , 16.v.1955, W.R.M. Mason (1, CNCI) ; San Bernardino , F.C. Bowditch Collection (3, MCZC) , MCZ-ENT00727018, MCZ-ENT00727020, MCZ-ENT00727022; Kern Co., Wofford Heights , 14–15.vii.1992, Henry and Anne Howden (4, CMNC) ; Greeley , W.G. Dietz Collection (4, MCZC) , MCZ-ENT00727048 – MCZ-ENT00727051; Kern. Co., Alta Sierra , 15.vii.1992, Henry and Anne Howden (3, CMNC) ; Modoc Co., Cedarville , 1.iv.1946, W.F. Barr (1, CMNC) ; Los Angeles Co., Boquette, Boquet Canyon , 11.iv.1974, M.W. Hetz (1, UAIC) ; Sonoma Co., 2 mi. N of Cloverdale , 27.iii.1964, C.W. O’ Brien, on Salix (6, CNCI) ; Humboldt Co., Alton , 1.viii.1937, B.P. Bliven (6, CAS) ; Humboldt Co., Willow Creek , 13.vi.1916, F.E. Blaisdell (22, CAS) ; Humboldt Co., Myers , 22.ix.1935, B.P. Bliven (4, CAS) ; Oroville , 30.iv.1927 – 24.vi.1927, H.H. Keifer, on Salix hindsiana (2, CAS) ; Oroville , 21.iv. 1928, H.H. Keifer (1, CAS) ; Trinity Co., Carrville , 1.vi.1913, Van Dyke Collection (1, CAS) ; Monterey Co., Carmel , 5.viii.1917, L.S. Slevin Collection (1, CAS) ; Sacramento , 27.iii.1937, B.E. White (2, CAS) ; Ahwahnee, May (2, CAS; 1, MCZC), MCZ-ENT00727156; Castle Crag, vii, A. Fenyes (2, CAS) ; Kaweah, R. Hopping (1, CAS) ; Truckee , 7.vii.1927, E.P. Van Duzee (1, CAS) ; Calaveras Co., Mokell Hill , 11.vi.1921, F.E. Blaisdell (1, CAS) ; Napa Co., Butts Canyon , 13 km NW of Pope Valley, 17.iv.1982, T.W. Davies (21, CAS) ; Yosemite , 27.v.1931, B.E. White (1, CAS) ; Riverside , 5.iv.1990, H.C. Fall Collection and F. Blanchard Collection (8, MCZC) , MCZ-ENT00727064 – MCZ-ENT00727067, MCZ-ENT00727145 – MCZ-ENT00727148; Ventura , 3.iv.1892, H.C. Fall Collection (1, MCZC) , MCZ-ENT00727149; Lassen Co., 4.vi.1913, H.C. Fall Collection and C.A. Frost Collection (9, MCZC) , MCZ-ENT00727076, MCZ-ENT00727077, MCZ-ENT00727150 – MCZ-ENT00727155; Plumas Co., 17.viii.1917, H.C. Fall Collection (2, MCZC) , MCZ-ENT00727157, MCZ-ENT00727158; Castle Crags , vii, H.C. Fall Collection (1, MCZC) , MCZ-ENT00727161; Visalia , Culbertson (1, MCZC) , MCZ-ENT00727159; Lake Tahoe , 24.v.1879, W.G. Dietz Collection (1, MCZC) , MCZ-ENT00727115; “Cal.”, Liebeck

Collection (3, MCZC), MCZ-ENT00726986 – MCZ-ENT00726988; Oregon: Lake Co., 8 mi. W of Adel, 24.v.1973, K.J. Goeden (4, CMNC) ; Klamath Co., Sprague River canyon, 5 mi. E of Bly, 22.v.1958, Vertrees and Schuh, on Salix (1, CMNC) .

Diagnosis. Length 2.1–2.6 mm. Scales on pronotum usually not uniform in colour, with discoloured central and lateral bands. Metaventrite and metepisternum with scales relatively sparse not obscuring underlying cuticle. Distinct swelling at the tip of last ventrite of males (no longitudinal carina at middle of ventrite; often reduced or absent in smaller specimens). Apex of aedeagus quadrate to rounded, dorsoventrally flattened, and coming to a distinct, sharp point with two prominent tufts of setae. Aedeagus heavily sclerotised along lateral edges. Internal sac with protruding basal structures. Restricted to California and southern Oregon.

Distribution in North America. This species is restricted to California and southern Oregon. The apparent lack of overlap in the ranges of E. californicus and E. ephippiatus is notable, and further sampling of both species in the region may reveal differences in host plant preferences.

Remarks. This species occupies a region known for high rates of animal and plant endemism ( Harrison 2013), including several endemic Salix and Populus species ( Little 1979). Ellescus californicus has been collected from Salix exigua var. hindsiana (Bentham) Dorn , a plant endemic to southwest Oregon, California, and Baja California ( Mexico) ( Little 1979). Although this species was previously treated as a junior synonym of E. ephippiatus (O’ Brien and Wibmer 1982; Poole and Gentili 1996), the previously undocumented differences in male genitalia and lack of overlap in geographic range with E. ephippiatus support the status of E. californicus as a distinct species. Although molecular data were not secured for E. californicus due to a lack of recently collected specimens in examined museum collections, this species is clearly closely related to E. ephippiatus as it possesses (1) a prominent swelling at the tip of the last ventrite (males only), (2) discoloured (scales) pronotal bands, and (3) a pointed aedeagus and internal sac with protruding basal structures.

Figures

Fig. 5. Aedeagi of Ellescus species: A, Ellescus scanicus; B, Ellescus bipunctatus; C, Ellescus californicus; D, Ellescus michaeli new species; and E, Ellescus ephippiatus.

Fig. 6. Spermatheca of Ellescus species: A, Ellescus scanicus; B, Ellescus bipunctatus; and C, Ellescus californicus. Note that E. ephippiatus and E. michaeli new species are not presented because the spermatheca of these species do not differ noticeably from that of E. californicus.

Fig. 7. Ellescus californicus (Casey, 1885): A, dorsal view and B, lateral view.