Phylogenetic position of genera Acrostilicus Hubbard and Pachystilicus Casey (Staphylinidae, Paederinae) and their redescription Author Żyła, Dagmara 0A7FEB0F-308C-4FDF-AD0D-8074BC69F0B3 Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00 - 679 Warsaw, Poland. Department of Invertebrate Zoology and Parasitology, University of Gdańsk, 80 - 308, Gdańsk, Poland. Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50011, USA. zyladagmara@gmail.com Author Tokareva, Alexandra F2DB3539-310F-4453-81FA-A6BC0D5C885D Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00 - 679 Warsaw, Poland. Department of Invertebrate Zoology and Parasitology, University of Gdańsk, 80 - 308, Gdańsk, Poland. Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50011, USA. alexan4tok@gmail.com Author Koszela, Katarzyna 06C16202-4569-4156-9FB1-EA4DEE14AE88 Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00 - 679 Warsaw, Poland. Department of Invertebrate Zoology and Parasitology, University of Gdańsk, 80 - 308, Gdańsk, Poland. Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50011, USA. kat.koszela@gmail.com text European Journal of Taxonomy 2022 2022-05-09 819 1 1 22 http://dx.doi.org/10.5852/ejt.2022.819.1773 journal article 55622 10.5852/ejt.2022.819.1773 ad96f711-d952-4f41-8241-5646ea1751aa 2118-9773 6533014 6A5B371D-2A28-43C1-A6C3-12C8E7016515 Pachystilicus hanhami ( Wickham, 1898 ) Fig. 4 Stilicus hanhami Wickham, 1898: 220 (original description, notes). Pachystilicus hanhami – Casey 1905: 227 (redescription). — Blackwelder 1939: 107 , 120; 1952: 285 (notes). — Poole & Gentili 1996: 370 . — Webster 2016: 435 . — Newton et al. 2001: 387 (comment on taxonomic status). Diagnosis Differs from P. quadriceps by shorter and slightly sparser setae covering body, longitudinal carina of basisternum less elevated. Additionally, the median emargination of posterior margin of male sternite VIII is shallower and narrower than in P. quadriceps , with the depth of emargination ca 1/5 of sternite length. Type material Holotype USA • ♂ ; “ Winnipeg Man. Hanham / Wickham Collection 1933 / Type No 50215 U.S.N.M / Stilicus hanhami Wick. ? Type of drawing [?] of description”; NMNH . Additional studied material CANADA – Alberta • 1 spec. ; “[with ants] Banff. Alta. Aug. 20 ’15 Wheeler leg. / 00744589 ”; MCZ • 1 spec. ; “ Calgary , Hwy 4 , 2.IV.1981 , with ants [ Myrmica sp. ] under stone , B+J Carr”; MCZ • 1 spec. ; “ Calgary , Hwy 4 , 7.VI.1964 with ants [ Myrmica sp. ] under stone , B+J Carr”; MCZ • 1 spec. ; “ Calgary , Hwy 4 , 23.X.1955 with ants [ Myrmica sp. ] under stone , B+J Carr”; MCZ • 1 spec. ; “ Calgary , Hwy 4 , 13.X.1955 with ants [ Myrmica sp. ] under stone , B+J Carr”; MCZ • 1 spec. ; “ Calgary , Hwy 4 , 25.IV.1953 with ants [ Myrmica sp. ] under stone , B+J Carr”; MCZ • 1 spec. ; “ Calgary , Hwy 4 , 8.V.1953 with ants [ Myrmica sp. ] under stone , B+J Carr”; MCZ • 1 spec. ; “ Calgary , Hwy 4 , 24.III.1956 with ants [ Myrmica sp. ] under stone , B+J Carr”; MCZ • 1 spec. ; “ Banff , 17.IV.1955 , with ants , B+J Carr”; MCZ • 1 spec. ; “ Coleman , 26.VI.1961 , B+J Carr”; MCZ • 1 spec. ; “ Seebe , 14.X.1963 , B+J Carr”; MCZ • 1 spec. ; “ Canmore , 3.IV.1953 , B+J Carr”; MCZ • 1 spec. ; “ Canmore , 4.IV.1953 , B+J Carr”; MCZ • 1 spec. ; “ Ghost Dam , 22.III.1953 , B+J Carr”; CNC . – Manitoba • 1 spec. ; “ Winnipeg Man. Hanham / F. C. Bowditch Coll / Stilicus hanhami Wick / 00744583 ”; MCZ • 1 spec. ; “ Winnipeg Man. Hanham / Stilicus hanhami Wickh. / 00744584 ”; MCZ • 1 spec. ; “ Winnipeg Man. Hanham / ♀ / Fredrick Blanchard Collection / Stilicus hanhami Wickh. / 00744585 ”; MCZ • 1 spec. ; “ Winnipeg Man. Hanham / Wickham Collection 1933 / Stilicus hanhami Wickh. ”; MCZ • 1 spec. ; “ Winnipeg Man ./ CASEY bequest 1925 / Pachystilicus hanhami Wick. ”; MCZ • 1 spec. ; “ Winnipeg Man. Hanham / CASEY bequest 1925 / CASEY determination hanhami -2”; NMNH . USA – Massachusetts • 1 spec. ; “ Tyngs Mass. / ♂ / Fredrick Blanchard Collection / Stilicus quadriceps Lec. / 00744586 ”; MCZ • 1 spec. ; “ Under stones / C.A. Frost. IV Sherborn 17-10 Mass / Stilicus ? apicalis Csy / C.A. Frost Collection 196200744590 ”; MCZ • 1 spec. ; “ Frmghm ( Framingham? ) Mass Frost / H. C. Fall Collection / Stilicus hanhami / 00744532 ”; MCZ . – New Hampshire • 1 spec. ; “ Franconia N.H. / Liebeck Coll. / H. C. Fall Collection / 00744582 ”; MCZ • 1 spec. ; “ Franconia N.H. / with ants mas., blosson / Liebeck Coll. / H. C. Fall Collection / 00744581 ”; MCZ • 1 spec. ; “ Plainfield N.H. Oct. 9.27. / F.C. Bowditch Coll / Stilicus / 00744588 ”; MCZ • 1 spec. ; “ Plainfield N.H. Oct.9.27. / F.C. Bowditch Coll / Stilicus / 00744587 ”; MCZ . – Oklahoma • 1 spec. ; “Oklahoma: Latimer Co. , 5 Mi. W. Red oak , Oct. 1980 K. Stephen / Pachystilicus quadriceps Lec. ’ 84 det. L. E. Watrous”; TAMUIC • 1 spec. ; “ Nev. Elko Co. , Wildhorse Crossing St. Pk , R. Haswell 8.IX.15 / in ant nest under rock / Pachystilicus sp. det. R. Haswell 1922 / ex. Richard H. Haswell Collection, October 2008 , TAMU Insect Collection”; TAMUIC . Redescription MEASUREMENTS. Body length: 4.5 mm ; forebody length: 2.70–2.95 mm . COLOURATION. Dark brown to yellow; head darker, legs and antennae reddish brown, elytra (except for base) light brown to yellow. Abdomen black, tip lighter in colour ( Fig. 4A–B ). Fig. 4. Pachystilicus hanhami ( Wickham, 1898 ) , habitus photographs and drawings of the apical abdominal sternite and genital structures. A . Habitus, holotype, ♂ (NMNH). B . Habitus, additional male specimen with darker colouration (NMNH). C . Male sternite VIII. D . Aedeagus, parameral view. E . Aedeagus, lateral view. Scale bars = 0.5 mm. HEAD. As in generic description (HL: 0.9–1.0 mm; HW: 1.0– 1.1 mm ), with antennomere 1 elongate, widest at tip; antennomeres 2–4 elongate; antennomere 5 weakly elongate; antennomeres 6–10 gradually becoming transverse; antennomere 11 elongate, 1.5× as long as antennomere 10. Mandible with three teeth on right and left mandible, but two outer teeth on right mandible much larger than others. THORAX. As in generic description (pronotal size: PL: 0.8–0.9 mm ; PW: 0.8–0.9 mm ; elytra size: EL: 1.00– 1.05 mm ; EW: 1.2 mm ). ABDOMEN. As in generic description; sternite III with short medial longitudinal keel. Distribution The species has previously been recorded from the Canadian provinces of Alberta, British Columbia, Manitoba, New Brunswick, and Saskatchewan and the US state of Oregon ( Newton 2018 ). New records include the following US states: Massachusetts , New Hampshire , and Oklahoma .