Othius punctulatus, (GOEZE, 1777)

Rood, Rodney Jay, Brunke, Adam & Solodovnikov, Alexey, 2015, Othius punctulatus (Goeze, 1777) (Coleoptera: Staphylinidae) Detected in the Pacific Northwest: A Palearctic Genus New to the USA, The Coleopterists Bulletin 69 (3), pp. 412-414 : 412-413

OTHIUS PUNCTULATUS (GOEZE, 1777) ( COLEOPTERA : STAPHYLINIDAE ) DETECTED IN THE PACIFIC NORTHWEST: A PALEARCTIC GENUS NEW TO THE USA

RODNEY JAY ROOD 440 W. Main Pullman, WA 99163, U.S.A.

ADAM BRUNKE, AND ALEXEY SOLODOVNIKOV Biosystematics Section, Natural History Museum of Denmark Zoological Museum, Universitetsparken 15 Copenhagen 2100, DENMARK [e-mail]

During January 2011, one of us (RJR) collected a suspicious rove beetle in Whatcom County, Washington. Using regional keys for identification of rove beetles of North America ( Hatch 1957; Newton et al. 2000), RJR correctly determined that the beetle belongs to the subfamily Staphylininae , tribe Othiini . Based on external characters, the suspicious specimen did not match either Atrecus Jacquelin du Val, 1856 or Parothius Casey, 1906 , the only native Othiini genera known from the United States and included in the respective keys. Examination by AB and AS revealed that the mysterious Othiini represented Othius punctulatus (Goeze, 1777) , a common and widespread West Palearctic species. Soon after, additional specimens of this species collected during 2014 in Island County, Washington were discovered by RJR. These repetitive collections of O. punctulatus at different Washington localities and different years suggest that the species was recently introduced to North America and now is well established in the Pacific Northwest. The Eurasian genus Othius Stephens has been recorded only recently as adventive in North America ( Klimaszewski et al. 2013), based on a smaller species of the genus, Othius subuliformis Stephens, 1833 , found in Newfoundland ( Assing 2003). Data associated with the collections of O. punctulatus in the USA are presented here, and the existing key to North American genera of Staphylinidae ( Newton et al. 2000) is updated to include the genus Othius .

Material Examined. 9 specimens in total: 1 male, Washington : Whatcom Co. Deming - Reardon Prop. 5471 E. 45th Drive. Sumas Mt. Litter - Acer, Alnus, Tsuga, Pseudotsuga, Populus b.f. 8 Jan 2011, leg. R . J. Rood ( Zoological Museum , Copenhagen, Denmark, ZMUC) ; 7 males, 1 female, Washington : Island County, Whidbey Island , 655 Patmore Road , forest with Western Red Cedar 2nd or 3rd growth with some understory, Barrier pitfall trap, leg. R . H. McPeak, 31 Dec 2013 – 5 Jan 2014 (4 males, RJR private collection; 3 males, 1 female, William F. Barr Museum , University of Idaho , Moscow, Idaho, WFBM) .

Comments. The rove beetle tribe Othiini Thomson, 1859 comprises four genera: Parothius with two species endemic to western North America ( Smetana 1982; Newton et al. 2000); the Holarctic Atrecus with 14 species divided between North America (five species) and Eurasia (nine species) ( Herman 2001); the West Palearctic Caecolinus Jeannel, 1923 with a single species ( Smetana 2004); and the species-rich genus Othius with 126 species and subspecies mostly confined to the Palearctic region, some penetrating the Oriental region via higher elevations ( Assing 1997, 2013; for a map of the genus’ native distribution, see Assing 2003). Species of Parothius and Atrecus are recorded as associated with dead wood and are stenotopic ( Smetana 1982; Assing and Schülke 2012). Caecolinus endogaeus Jeannel, 1923 is endogean and rare in collections (Coiffiat 1972). Species of the genus Othius live in various ground-based debris of forests and open landscapes from lowlands to 3,000 m in the West Palearctic, and up to 4,500 m in the East Palearctic. They are typically confined to leaf litter in woodlands ( Assing 1997, 2003). Many species, especially those occurring at mid- to higher elevations in the mountains are stenotopic and have restricted distributions. Other Othius species (e.g., O. lapidicola Märkel and Kiesenwetter, 1847 , O. angustus Stephens, 1833 , O. laeviusculus Stephens, 1833 , O. subuliformis , and O. punctulatus ) are polytopic and widespread, suggesting high ecological plasticity and strong dispersal power. Thanks to revisionary studies in the form of 18 installments by Volker Assing, most recently Assing (2013), Othius is systematically and ecologically well known among large rove beetle genera. Nevertheless, only two previous examples of human-induced introductions were known for Othius (and Othiini in general): the occurrence of O. punctulatus on the Canary Islands ( Assing 1997) and the occurrence of O. subuliformis in Newfoundland ( Assing 2003).

Othius punctulatus is a widespread and ecologically plastic species ( Assing 1997; Assing and Schülke 2012). The native distribution covers a wide area from western North Africa, through all of Europe to Asia Minor and the Caucasus, although the eastern limits of the species’ distribution are unclear. It is not known from some of the Greek islands and considered introduced to the Canary Islands. In northern parts of its range, O. punctulatus occurs at lower elevations and is restricted to higher altitudes (up to 2,100 m in Morocco) in the south. It is a eurytopic, mainly woodland-associated predator of small invertebrates, with recorded wing polymorphism where only some members of the populations are able to fly. Larval descriptions can be found in Kasule (1970).

Specimens on which this report is based were collected in native forest leaf litter during winter. Both localities are near Puget Sound and within 142 km of Seattle and Vancouver, and near Bellingham. The area is a major epicenter of global shipping, rail and air commerce and trade as well as ferry traffic within Puget Sound and the Alaskan ferry system. Plants and soil in nursery cargo from overseas are likely sources of the introduction(s).

Othius can be included in the key to the Nearctic genera of Othiini ( Newton et al. 2000) with the modification provided below. Confirmation of species identification is possible by comparisons of the dorsal habitus and aedeagus with published sources ( Assing 1997; Assing and Schülke 2012), reproduced here ( Fig. 1 , habitus; Fig. 2 , aedeagus).

1. Disk of pronotum with a single pair of punctures near middle; apical maxillary palpomere fusiform, distinctly longer than penultimate palpomere; length of head from base of labrum to neck constriction not exceeding maximal head width............................................ Atrecus

- Disk of pronotum with more than a single pair of punctures near middle; apical maxillary palpomere either conical or fusiform; length of head from base of labrum to neck constriction slightly to distinctly exceeding maximal head width.....................................................2

2. Disk of pronotum with at least 4 pairs of punctures forming paramedian rows; apical maxillary palpomere conical, not longer than penultimate palpomere; California to British Columbia ... ...................................................... Parothius

- Disk of pronotum with 3 pairs of punctures near middle; apical maxillary palpomere fusiform, not longer than penultimate palpomere. Adventive: known from small distributions on East and West coasts ....................................... Othius

Figures

Fig. 1. Othius punctulatus, habitus. Photograph by Harald Schillhammer, reproduced with permission.

Fig. 2. Othius punctulatus, aedeagus. A) Lateral view, B) Dorsal (parameral) view. Scale = 0.5 mm. Modified from Assing (1997).