Myrmedonota aidani Maruyama & Klimaszewski

Maruyama, Munetoshi, Patrick, Brian & Klimaszewski, Jan, 2008, First record of the genus Myrmedonota Cameron (Coleoptera, Staphylinidae) from North America, with descriptions of two new species, Zootaxa 1716, pp. 35-43 : 37-40

Myrmedonota aidani Maruyama & Klimaszewski , sp. nov.

Figs. 1 , 3–12

Type series. Holotype, ɗ, UNITED STATES OF AMERICA: Ohio: Summit County, Bath Nature Preserve [41.18°N, 81.65°W], 20 VI 2003 – 4 VII 2003, coll. L. B. Patrick ( LFC). Paratypes: 5 ɗɗ, 5 ΨΨ, same data as holotype ( LFC, FMNH); 5 ɗɗ, 3 ΨΨ, 2 sex?, same data but 30 VI 2005 – 14 VII 2005 ( LFC, CNC, cMM); 3 ɗɗ, 1 Ψ, same data but 28 VII 2005 – 11 VIII 2005 (cMM).

Etymology. Dedicated to Aidan C. Patrick, son of the collector of the original series, L. Brian Patrick.

Diagnosis. This species is closely similar to M. lewisi in facies and body size but may be easily distinguished by the mostly reddish-brown body color, the morphology of the genital organs, especially the wider dorsal bridge of the median lobe of aedeagus and the S-shaped spermatheca. This species can easily be separated from the other known species of Myrmedonota by having 5 macrosetae along the lateral margin of the pronotum.

Description. Body slender and subparallel ( Fig. 1 ). Reddish-brown in ground color; head, 5th to 11th segments of antennae, 5th to 8th segments (sometimes also median areas of 4th and 5th segments) of abdomen blackish brown; elytra paler, but more or less infuscate laterally and sometimes around scutellum. Head ( Fig. 1 ) widest at eyes; surface finely reticulated, moderately covered with setae; setae moderately long, as long as those on pronotum and elytra; length of eyes 0.45–0.46 times as long as head width. Mentum (Fig. 4) trapezoidal, with basal margin emarginate. Labium (Fig. 5) with about 30 minute medial pseudopores. Antennae ( Fig. 1 ) shorter than head, pronotum and elytra combined; 1st segment much shorter than 2nd and 3rd combined; 2nd segment about 0.7 times as long as 3rd; 3rd segment about 0.8 times as long as 1st; 4th to 10th segments almost as long as wide except for stem of each segment; 11th segment conical, longer than 1st. Pronotum ( Fig. 1 ) subelliptical, 1.37–1.44 times as wide as long, widest just after anterior margin; surface finely punctured, finely reticulated among punctures, densely covered with setae, with 5 long macrosetae along anterior to lateral margins; lengths of macrosetae variable, anterolateral one longest. Scutellum with surface smooth, moderately covered with short setae. Elytra ( Fig. 1 ) widened apicad; surface finely punctured, finely reticulated among punctures, densely covered with setae, with 3 small macrosetae laterally. Legs short; hind tibia 0.81– 0.84 times as long as elytral width. Abdomen subparallel-sided, slightly narrower than elytra, widest around 4th and 5th segments; surface smooth; 3rd to 7th tergites almost glabrous, but with a row of setae and macrosetae along posterior margins; 8th tergite (Figs. 6, 10) with 5 macrosetae; 9th tergite with 4 macrosetae; 10th tergite with posterior margin slightly emarginate, with 4 macrosetae.

Male. Eighth abdominal tergite (Fig. 6) with posterior margin truncate, its truncate apex crenate, and with a protrusion laterally; 8th sternite (Fig. 7) with posterior margin rounded, with 8 macrosetae; 9th sternite with posterior margin rounded. Aedeagus (Figs. 8, 9) somewhat tear-shaped in parameral view; apical lobe gently curved paramerally in lateral view, pointed at apex in lateral and parameral views; basal ridge convex.

Female: Eighth abdominal tergite (Fig. 10) with posterior margin truncate; 8th sternite (Fig. 11) with 7 macrosetae; sensory setae of 8th sternite generalised, almost the same as the other setae in shape. Spermatheca (Fig. 12) curved twice, S-shaped.

Mouthparts of Myrmedonota aidani . 3: maxilla; 4: mentum; 5: labium.

FIGURES 6–12. Terminalia of Myrmedonota aidani . 6: male 8th tergite; 7: male 8th sternite; 8: median lobe of aedeagus, lateral view; 9: median lobe of aedeagus, parameral view; 10: female 8th tergite; 11: female 8th sternite; 12: spermatheca.

Measurements. BL, ca. 2.6–3.0; FBL, ca. 1.2–1.4; HW, 0.49–0.52; EL, 0.220–0.237; AL, 1.03–1.13; PL, 0.43–0.47; PW, 0.59–0.67; ELW, 0.75–0.86; HTL, 0.63–0.68.

Comments. This species, as well as the next species, are distinguishable from the other congeners in having 5 macrosetae along the lateral margin of the pronotum. The other species are characterized by having 3 or 4 setae along lateral margin of pronotum ( Kistner, 2003).

Bionomics. This species was readily caught in pitfall traps with a 50/50 solution of water/propylene glycol. The habitat was an annually mown old-field grassland dominated by the European cool season grasses, Bromus inermis Leyss. , Festuca arundinacea Schreb. , Phleum pratense L., and Anthoxanthum odoratum L. The species was captured frequently in anthropogenically disturbed areas, especially with moderate to high plant productivity, and with moderate to high plant litter accumulation.

The type series specimens of M. aidani were caught with ants ( Formicidae ), though the exact species of ants were not determined, only the subfamily. Captured with the type series of this species were several specimens in each of the following subfamilies: Mymicinae, Dolichoderinae , and Formicinae . Additionally, a single specimen of the subfamily Ponerinae (presumably Ponera pennsylvanica Buckley ) was captured with the holotype of M. aidani . Additional specimens of M. aidani not in the type series were captured with the following ant species: Lasius neoniger Emery , Lasius alienus (Foerster) , Lasius umbratus (Nylander) , Brachymyrmex depilis Emery , Prenolepis imparis (Say) , Formica nitidiventris Emery , Myrmica latifrons Stärcke , Myrmica americana Weber , Myrmica fracticornis Forel , Stenamma brevicorne (Mayr) , Stenamma impar Forel , Solenopsis molesta (Say) , Aphaenogaster rudis complex (Enzmann), and Ponera pennsylvanica Buckley. Further , M. aidani of the type series were captured with the following beetle species: Amara lunicollis Schiodte and Poecilus lucublandus (Say) in the family Carabidae , Barypeithes pallucidus (Boheman) in the family Curculionidae , and Apocellis sphaericollis (Say), Falagria dissecta Erichson , Philhygra clemens (Casey) , Amischa sp., and Meronera venustula Erichson in the family Staphylinidae .

This species, as well as the next species, is most probably myrmecophilous, though none of the type series of the next species were collected with ants. Most species of the Lomechusini are considered to be myrmecophilous ( Maruyama, 2006), and the present new species are closely similar to the type species, which has been presumed to be a myrmecophile. Further field investigation is needed for confirmation of their myrmecophily.

Figures

FIGURES 1, 2. Habitus of Myrmedonota spp. 1: M. aidani; 2: M. lewisi, teminal segements 9 - 10 removed and not shown.