Diglotta mersa (Haliday) and Halobrecta flavipes Thomson, two new species for the Canadian fauna (Coleoptera, Staphylinidae, Aleocharinae)

Diglotta mersa (Haliday) of the Diglottini, a western Palaearctic species, is reported for the fi rst time from the Atlantic coast of North America (Canada, New Brunswick). It was found in fi ne gravel under small (10-15 cm diameter) rocks in the intertidal zone, approximately 2 m below the mean high tide mark. A description, and images of the external body, median lobe of aedeagus, spermatheca and terminal segments are provided. New distributional and bionomic data for Halobrecta fl avipes Th omson, a coastal species of the Athetini Casey, are presented.

Th e objective of this paper is to document the fi rst distribution record of Diglotta mersa (Haliday) in North America and to provide new distributional and bionomic data on another coastal species, Halobrecta fl avipes, previously recorded in North America from New York and Virginia (Gusarov 2004).

Material and methods
Th irty-nine adults of D. mersa from Dipper Harbour, and fi fty-seven specimens of H. fl avipes from Chance Harbour, New Brunswick, were examined.Twelve specimens of D. mersa were dissected.Th e genital structures were dehydrated in absolute alcohol and mounted in Canada balsam on celluloid microslides and pinned with the specimens from which they originated.Th e photographs of the entire body and the genital structures were taken using an image processing system (Nikon SMZ 1500 stereoscopic microscope; Nikon Digital Camera DXM 1200F; and Adobe Photoshop software).
Terminology mainly follows that used by Caron and Ribeiro-Costa (2008).Th e ventral part of the median lobe of the aedeagus is considered to be the part of the bulbus containing the foramen mediale, the entrance of the ductus ejaculatorius, and the adjacent venter of the tubus; the opposite side is referred to as the dorsal part.Lea, 1927 Fiji Islands (Levuka) Lea (1927);Haghebaert (1991) 4-4-5

Diagnosis
Integument with slightly granulate microsculpture, pubescent, pubescence short and of distinct pattern on pronotum with microsetae forming arcuate lines emerging from midline of the disc outwards (Fig. 1).Body with large, broadly rounded head and protruding mouthparts forming conically-shaped apical projection, head as large as or larger than pronotum (Fig. 1); infraorbital carinae absent; labrum broadly emarginate medially; mandibles slender with rounded blunt apices, prostheca well developed; lacinia and galea of equal length; maxillary palpus with four articles, fi rst and last reduced in size; mentum trapezoidal in shape, anterior margin strongly concave; pronotum strongly narrowed basally (Fig. 1); elytra shorter than pronotum (Fig. 1); hind wings usually reduced to short stubs, but micropterous and macropterous forms within the same species are reported (Good 1998); abdomen broadly oval in dorsal outline and widening posteriorly (Fig. 1).Found in the intertidal zone of beaches (Moore and Orth 1979;Good 1998;Haghebaert 1991;Pace 1989, Ashe 2001).

Key to the Diglotta species recorded from the Nearctic region
Th e following key was modifi ed from Haghebaert (1991).Elytral length was measured from the humeral angle to the hind margin; body length was measured from the apical margin of the labrum to the apex of the abdomen.Th e body length is given without range for species known only from a holotype (D. littoralis), or where such data was not available from the literature.For descriptions and genital illustrations of D. legneri, D. littoralis and D. pacifi ca see Haghebaert (1991).

Distribution
Diglotta mersa has previously been reported from coastal areas of Europe: Albania, Belgium, Denmark, France, Great Britain, Germany, Ireland, Italy and the Netherlands (Smetana 2004), but due to previous species misinterpretation (Good 1998), the distribution in the Western Palaearctic requires revision.We report this species for the fi rst time from the Atlantic coast of North America (Canada: New Brunswick).Diglotta mersa is wing-dimorphic and both winged and wingless forms have been reported in Europe (Good 1998).Th ese observations suggest that the species is capable of longdistance dispersal and may be adventive on the Atlantic coast of North America.

Collection data
Sixteen specimens were captured on 12 May 2008 on fi ne gravel under or adjacent to 10-15 cm rocks in the intertidal zone, approximately 2 m below the mean high tide mark (Figs. 13,14).Rocks at this site were largely free of algae.An additional 24 specimens were found in July on sea beaches under 10-30 cm diameter rock in sand, about 4.0 m below mean high tide mark, and under 10-80 cm diameter rocks in sand, 2.0 to 5.0 m below mean high tide mark.

Comments
Th e median lobe of the aedeagus of the holotype of Diglotta littoralis (Horn) is illustrated in Fig. 12. Th is is the only other species of the genus occurring on the Atlantic coast of North America and it is known only from the holotype, which was collected in New Jersey.Th e median lobe of this species is presented here for the fi rst time.

Bionomic notes
Fifty-seven adults of H. fl avipes were collected from under large deep-set rocks 3.0 to 3.5 m below the mean high tide mark at Chance Harbour in May and July 2008.Many other adults were observed under rocks on these dates.Micralymma marinum (Ström) (Staphylinidae, Omalinae) was also common under deep-set rocks at this site, but a few individuals were also observed on the surface of the gravel adjacent to the rocks.Mating pairs of M. marinum were also observed under the rocks.Th ree adults of H. fl avipes were found under decaying seaweed near the mean high tide mark on 7 May 2006.However, no adults were observed in decaying seaweed or other drift material near the mean high tide mark in 2008.
It is noteworthy that the Brazilian species has a tarsal formula of 4-4-4 while all native North American species have 4-4-5-articulated tarsi.Th e tarsal articulation of all known Diglotta species should be reexamined and confi rmed.Based on such a reexamination, the two groups will probably warrant distinct taxonomic status.
Based on the available zoogeographic data, an explanation of the presence of D. mersa in New Brunswick may seem somewhat speculative.However, because the species is wing-dimorphic (Good 1998), and due to the absence of its previous records in North America, it is plausible to believe that the North American population originated in Europe.

Table 1 .
World checklist of Diglotta species.New record is in bold.