Ellescus michaeli Lewis and Anderson, 2023

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 : 15-16

Ellescus michaeli Lewis and Anderson , new species

https://zoobank.org/ urn:lsid:zoobank.org:act:469C9178-DB98-443B-A23C-E65BA1B61FFB

Figs. 5D , 8

Specimens examined

Holotype. CANADA: Ontario: Mer Bleue Bog , 45.3973° N, 75.5144° W, 13.v.2021, R.S. Anderson, male beaten off Salix sp. , (male, CMNC).

Paratypes. CANADA: Alberta: Edmonton , 10.v.1915 – 27.v.1919, F.S. Carr (2, UAIC; 1 CNCI; 1 MCZC), MCZ-ENT00727116; Edmonton, Liebeck Collection (3, MCZC) , MCZ-ENT00727009 – MCZ-ENT00727011; Peace River (18 mi. S), 2.vi.1950, P. Rubtsoff (3, CNCI) ; Ghost Dam , 10.vi.1980, B.F. and J.L. Carr (1, CNCI) ; Calgary , 21.v.1956, B.F. and J.L. Carr (1, CNCI) ; Manitoba: Aweme, 15–26.v.1903, N. Criddle (1, DEBU; 5, MCZC), DEBU01089099, MCZ-ENT00726992 – MCZ-ENT00726995, MCZ-ENT00727079; Riding Mountain National Park , 4–6.vi.1938, W.J. Brown (3, CNCI) ; Carberry , 8–10.v.1953, Brooks – Kelton (5, CNCI) ; Makinak (4, CNCI) ; Winnipeg , 24.v.1909 – 27.iv.1916, J.B. Wallis (7, RAM) , 1983.001; Ontario: Prince Edward Co., 10.v.1915 – 26.v.1955, Brimley (11, CNCI) ; Smoky Falls, Mattagami River , 8.vi.1934, G.S. Walley (1, CNCI) ; Ottawa , 7.v.1960 – 11.vi.1965, A.T. Howden (17, CMNC) ; Kanata, Corkstown Rd. , 11.v.1975, J.D. Read (1, CMNC) ; North Gower , 28.iv.–4.v.1987, L. LeSage, old beaver meadow, attracted with allylisothiocyanate (2, CMNC) ; Ottawa, Mer Bleue Bog (45.3973° N, 75.5144° W), 13.v.2021, R.S. Anderson, beaten off Salix sp. (15, CMNC) , LEW_145, OP215794 (GenBank CO 1 accession number), OP218955 (GenBank ITS 2 accession number), LEW_146, OP215795 (GenBank CO 1 accession number), LEW_147, OP218956 (GenBank ITS 2 accession number), LEW_148, OP215796 (GenBank CO 1 accession number), OP218957 ( GenBank ITS 2 accession number), LEW_149, OP215797 (GenBank CO 1 accession number); Mer Bleue , 10.v.1933, W.J. Brown (75, CNCI) ; Wellington Co., Guelph, 3.v.1982, D. Morris (1, DEBU), DEBU01089097 ; Marmora , 22.iv.–8.viii.1952, J.C. Mitchell, on Salix (6, CNCI) ; Quebec: Cantley , 45.591637° N, 75.785395° W, 23.iv.2021, J.H. Lewis, beaten off Salix sp. , (1, CMNC) , LEW_130, OP215793 (GenBank CO 1 accession number); Rigaud (4, MCZC) , MCZ-ENT00727124 – MCZ-ENT00727127; Montreal , v.1929– 10.v.1931, H.C. Fall Collection and Liebeck Collection (2, MCZC) , MCZ-ENT00727007, MCZ-ENT00727160; Aylmer (Gatineau), Pink Road (near CMN natural history campus), 21.iv.2008, L. LeSage, on Salix discolor catkins (8, CNCI) ; Cantley, dune on hill near chemin Holmes (45.591708° N, 75.784886° W), 22.v.2020, J.H. Lewis, on female Salix catkins (2, CMNC) , LEW_67, OP215790 (GenBank CO 1 accession number), OP765914 (GenBank ITS 2 accession number), LEW_68, OP215791 (GenBank CO 1 accession number), OP218942 ( GenBank ITS 2 accession number); Gatineau , Mont Cascades (45.590976° N, 75.850493° W), 14.v.2021, J.H. Lewis, beaten from Salix (1, CMNC) ; Aylmer, disturbed lot across road from 1740 Pink Road (45.441961° N, 75.811547° W), 10.v.2020, J.H. Lewis, on female Salix catkins (1, CMNC) , LEW_70, OP215792 (GenBank CO 1 accession number); Aylmer, disturbed lot across road from 1740 Pink Road (45.441961° N, 75.811547° W), 6.v.2022, J.H. Lewis, on Salix catkins (20, JHLC) ; Gatineau, Boucher Forest (45.416327° N, 75.826699° W), 18.v.2021, J.H. Lewis, beaten from Salix (3, CMNC) ; 28.vi.1965, Malaise trap (1, CNCI) ; Kazubazua , 25.v.1933, W.J. Brown (1, CNCI) ; Mont St. Hilaire, v.1909 (1, CNCI) ; Saskatchewan: Saskatoon , 21.v.1940, A.R. Brooks (1, CNCI) ; Canora , 28.v.1954, Brooks – Wallis (1, CNCI) ; Fish Creek , 20.v.1921, K.M. King (1, CNCI) ; UNITED STATES OF AMERICA: Maine: Penobscot Co., Orono , 24.v.1948 (2, UAIC), UAIC1072936 , UAIC1072937 ; Michigan: Oakland Co., Royal Oak , 10.vi.1916, A.W. Andrews (2, MCZC) , MCZ-ENT00727163, MCZ-ENT00727164; Whitefish Point , 26.vii.1914, H.C. Fall Collection (1, MCZC) , MCZ-ENT00727162; Lansing , Liebeck Collection (1, MCZC) , MCZ-ENT00727015; Minnesota: Otter Tail Co., Maplewood St. Pk. , 28.v.1983, I.S. Askevold, sweeps of Salix (2, CMNC; 1, UAIC) ; New Hampshire: Mount Washington, vii.1910, Liebeck Collection (1, MCZC) , MCZ-ENT00727001; Pennsylvania: Warren, A. Fenyes (1, CAS); Wisconsin: University of Wisconsin – Madison Arboretum , 30.iv.1949, R.H. Jones (7, CNCI) .

Diagnosis. Length 1.9–2.2mm. 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. Metaventrite (black to dark red) usually not contrasting with femora, tibiae, or latter half of rostrum. Elytral colouration distinct; largely dark with contrasting orange band in apical half. Lacking a distinct swelling at the tip of last ventrite of males. Apex of aedeagus coming to a broad, rounded point, with apical edges flattened laterally; also with setae distributed along the surface. Internal sac with protruding basal structures. Distributed across temperate North America.

Distribution in North America. This species is broadly distributed across Canada, from Quebec to Alberta, and is also known from several northern American states including Maine, Minnesota, and Wisconsin. The species has been collected in large series from the Ottawa– Gatineau region, Ontario and Quebec, where it is often the most abundant species of Ellescus ; it is only known from short series or single specimens in most other provinces and states.

Variation. Colour is relatively conserved in this species across its range (overall dark, with a bright, contrasting orange band across the apical half of the elytra; Fig. 8A, B ). However, all-red specimens are known from Otter Tail Co., Minnesota and two localities in Manitoba (e.g., Fig. 8C, D ). All-red forms also occur in E. ephippiatus and E. bipunctatus and are usually cases of geographic variation rather than teneral or aberrant colouration. The all-red forms of Ellescus michaeli may also represent instances of geographic variation. All-red forms are especially common in western Canadian population of Ellescus , and it is not uncommon to encounter series which contain mixtures of all-red forms of all three species. Dissection of males and to a lesser extent females is sometimes necessary in those cases to accurately identify specimens to the species level.

Etymology. This patronym is dedicated to Dr. Michael Košťál ( Slovakia), a weevil expert who graciously collected and mailed fresh specimens of Palearctic Ellescus for use in this project.

Natural history. This species has been collected from S. discolor Muhlenberg , S. petiolaris Sm. , and S. bebbiana Sargent. Collections for this study revealed that this species emerges in early spring and can be found inactive on female Salix catkins on colder mid- to late April days. This species appears to be active earlier in the spring than E. ephippiatus , and unlike that species, Ellescus michaeli has yet to be collected from Populus trees.

Remarks. The combination of unique male genitalia, colour, and ITS 2 sequence data ( Fig. 2 ) support E. michaeli as a new species. Notably, CO 1 did not delineate E. michaeli and E. ephippiatus (see Fig. 1 ), but ITS 2 reliably did so for all specimens examined. This illustrates the importance of using multiple markers in taxonomy and also that CO 1 alone does not separate species in all cases. Molecular data (CO 1, ITS2) and morphology indicate that E. michaeli is closely related to the more widespread and variable E. ephippiatus . To preclude a possible introduction, all currently recognised Old World Ellescus were examined and are all morphologically unlike E. michaeli .

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. 8. Ellescus michaeli new species: A, dorsal view of typical specimen; B, lateral view of typical specimen; C, dorsal view of all-red specimen from Otter Tail Co., Minnesota, United States of America; and D, lateral view of all-red specimen from Otter Tail Co., Minnesota.

Fig. 2. Neighbour-joining tree (ITS2) for Ellescus species under a Jukes–Cantor substitution model (10 000 bootstrap replicates, support threshold of 70%).

Fig. 1. Neighbour-joining tree (CO1) for Ellescus species under a Jukes–Cantor substitution model (10 000 bootstrap replicates, support threshold of 70%). Note that Ellescus ephippiatus and Ellescus michaeli new species do not separate when CO1 is used but do separate when the faster-evolving marker ITS2 is used (see Fig. 2).