The adventive genus Xantholinus Dejean (Coleoptera, Staphylinidae, Staphylininae in North America: new records and a synthesis of distributional data

Abstract New distributional and bionomic data are provided for species of the genus Xantholinus in North America. Xantholinus elegans (Olivier 1795) (= X. jarrigei Coiffait 1956)is recorded from North America for the first time, based on specimens collected in Ontario, Canada from 2007-2010. The armature of the internal sac of the aedeagus in situ is illustrated to aid in identification. Xantholinus linearis (Olivier 1795), known previously from the Maritime Provinces of Canada and the eastern United States, is newly recorded from Ontario. Xantholinus longiventris Heer 1839 is still only known from western North America. A key is provided to allow recognition of all three species.


Introduction
Th e genus Xantholinus Dejean (Staphylininae: Xantholinini) is a diverse, mainly Palearctic group and contains several species that prefer open, disturbed areas, where they often dominate the staphylinid assemblage (Daccordi and Zanett 1989;Balog and Marko 2007). Th ese habits have likely facilitated the accidental importation and subsequent establishment of Xantholinus species into North America. Smetana (1982) reported X. linearis (Olivier, 1795) from both eastern and western portions of the North America and X. longiventris (Olivier, 1795) only from western regions. Since then, several publications have presented either new provincial and state records, or additional locality data for these two species (Smetana 1988(Smetana , 1990Majka and Klimaszewski 2008a;Majka et al. 2008).
Recent collections and surveys in Ontario have resulted in the recognition of one additional species in North America and a range extension for X. linearis. We here summarize all available data for Xantholinus species in North America, present distributional maps, and provide a key for identifi cation of the species known from the continent.

Material and methods
Th e aedeagus of X. elegans (Olivier, 1795) was prepared for examination as in Smetana (1982) and photographed using an imaging system by Visionary Digital. Th e specimen photograph of X. elegans was taken with the same system. Maps were created using ARC-GIS and Abode Photoshop software. Th e institutions (and their abbreviations) from which material was examined are as follows:

ACPE
Agriculture  Xantholinus elegans is newly recorded from North America based on the above specimens collected near Guelph and near Marmora, Ontario, Canada (Fig. 1). Dissected specimens key out to X. jarrigei Coiff ait in Coiff ait (1972), a species synonymized with X. elegans (Olivier) by Drugmand (1994). Th e aedeagus is illustrated in Fig. 2 and those of the other two species were illustrated by Smetana (1982). Most specimens were found in strongly disturbed areas and all individuals were brachypterous. One larva was found under a rock at the edge of a disturbed woodlot in April 10, 2010 and was subsequently reared to an adult on May 15th. Th e larva was provided with soil from the collection site which included oribatid mites and early-instar Oniscus asellus, although the larva was never observed to feed.  (2)  American ones are from 1930 (in Washington state) (Majka and Klimaszewski 2008a). Th e current distribution of X. linearis is summarized in Fig. 3.

Discussion
Xantholinus elegans is certainly a recent accidental introduction to North America as it was not included in Smetana (1990), and the earliest specimen known is from 2007. In its native range, X. elegans is distributed widely in the western Palearctic region and recorded from Austria, Belgium, Bosnia Herzegovina, Czech Republic, France, Great Britain, Germany, Hungary, Ireland, Italy, Luxembourg, Th e Netherlands, Poland, Slovakia and Spain (Smetana in Löbl and Smetana 2004). In Europe, it prefers sandy soils and is a bivoltine species with most adults collected in spring and late summer (Daccordi and Zanetti 1989;Drugmand 1994). While most North American specimens were found on sandy soil, adults were collected throughout the summer and sparingly in spring and fall. Further collecting should help determine whether this is a collecting Figure 3. Distribution of X. linearis in North America. Distribution incorporates previous records from the literature (Smetana 1982(Smetana , 1988(Smetana , 1990Sikes 2003, Majka andKlimaszewski 2008).
artefact or a shift in seasonality in response to a diff erent geographic area. Th e majority of specimens have been collected in disturbed habitats and it is unknown if this species will invade habitats with little to no recent human disturbance. It is unclear whether the easternmost record (Marmora) (Fig. 1) represents an isolated population as a result of human-aided dispersal, or if it indicates an inadequately sampled, broader distribution in southern Ontario. Th e method of introduction is unknown but may be related to the importation of plant stock or associated materials as X. linearis was intercepted twice in soil with primrose and moss shipments from Europe in the 1930's (Smetana 1982). Other predatory beetles are suspected to have become established via plant stock importation (Spence and Spence 1988). Although exotic staphylinids are typically considered to enter eastern North America via Atlantic Canadian introduction points in Nova Scotia, Newfoundland, and in Massachusetts -many associated with historic shipments of dry ballast material (Smetana 1995;Majka and Klimaszewski 2008b) -examination of recent material from the University of New Hampshire Insect Collection and numerous collections in Maritime Canada have not turned up specimens of this species. It appears that the North American occurrence of X. elegans represents an inland introduction, similar to that of the Emerald Ash Borer, which was fi rst detected in  (Smetana 1982(Smetana , 1988.   Michigan/southern Ontario in 2002 (Poland et al. 2006). Although X. elegans is a brachypterous species (Assing 1993;Drugmand 1994) and is unable to disperse aerially, other beetles introduced to North America were found to disperse readily, despite their brachyptery (Spence and Spence 1988). Th e availability of suitable, open habitat in eastern North America may provide for the expansion of its range to include regions other than Ontario.
Xantholinus linearis was considered to be well-established in both eastern and western North America by Smetana (1982Smetana ( , 1988Smetana ( , 1990 and data presented in this paper demonstrate that it is continuing to expand its range towards the centre of the continent. Th is species was previously known from British Columbia, Nova Scotia, New Brunswick, Newfoundland and Prince Edward Island in Canada, and California, Idaho, Massachusetts, New Hampshire, Nevada, Oregon, Rhode Island, Utah, and Washington in the United States (Smetana 1982;Smetana 1990;Chandler 2001;Sikes 2003;Majka and Klimaszewski 2008a;Klimaszewski et al. 2010). While it has been known from Atlantic Canada since 1949, it appears to have only recently reached Ontario, as it is missing from collections made prior to 2008. Specimens from Pennsylvania and New York were clearly stated as 'interceptions' by Smetana (1982) and should not be considered as evidence that this species occurs there. Interestingly, recent surveys of open fi eld habitat in both these states have not detected X. linearis (Byers et al., 2000). Further survey work is needed to fully delimit the eastern range of this species.
Xanthlinus longiventris is still known only from the western United States (California, Oregon, Washington) and has not been reported from additional states or any provinces since it was treated in Smetana (1982). In North America, habitat data from specimens suggests that X. longiventris, while it often co-occurs with X. linearis, prefers a higher level of moisture (in moss, near water etc.) as it has not been collected from drier urbanized places where the latter species is often found. Th is species' range in North America is probably confi ned by the Rocky Mountain system and will likely remain stable in the absence of secondary introductions.
Th ree species of Xantholinus are now known to have established themselves in North America via human activity. Of these, at least X. linearis is apparently continuing to expand its distribution towards the centre of the continent and may be detected in additional provinces and states in the future. Th is paper provides a current synthesis of distributional information and facilitates the identifi cation of a previously unrecognized species for the North American fauna. A complete review and identifi cation manual for the entire Xantholinini in eastern North America is currently in preparation.
Research Reserve for permission to conduct surveys on their properties. Th is research was partially supported by a NSERC PGS-M awarded to A. Brunke. C.G. Majka acknowledges the ongoing support of the Board of Governors of the Nova Scotia Museum. David Langor graciously provided the locality data for the Newfoundland specimens of X. linearis. Stephen Marshall read an earlier version of this manuscript and provided helpful comments and suggestions.