Lomechusini Flemming

Eldredge, K. Taro, 2011, Bothronotoxenus Eldredge, A New Genus Of Aleocharinae (Coleoptera: Staphylinidae) From Arizona, U. S. A., The Coleopterists Bulletin 65 (4), pp. 381-386 : 381-383

Lomechusini Flemming

Diagnosis. The aleocharine tribe Lomechusini is a morphologically diverse tribe that has not been

satisfactorily defined, but the following characters are often applied to the group: 1) galea elongate; 2) mesocoxae broadly separated; 3) metaventral process much longer than mesoventral process, which extends slightly between mesocoxae; 4) athetine bridge of median lobe present; 5) proximal separation of median lobe that receives compressor plate deeply divided, appearing as if almost reaching parameral proximal costa in lateral view; 6) tarsal formula 4-5-5 ( Seevers 1978; Newton et al. 2000; Maruyama 2006).

KEY TO THE NORTH AMERICAN GENERA OF LOMECHUSINI

1. Abdomen petiolate; head and prothorax with smooth intervals between large setigerous impressions; host not known ......................... ........ Ecitocala rugosa Frank and Thomas

1′. Abdomen not petiolate; sculpture of head and prothorax different........................................2

2. Pronotum with deep, medial, longitudinal sulcus; occurs with ant species Neivamyrmex nigrescens (Cresson) ....................................... ...................... Ecitonidia wheeleri Wasmann

2′. Pronotum without sulcus..............................3

3. Head with prominent Y-shaped carina with bifurcation extending posteriorly; pronotum carinate; occurs with ants in the genus Neivamyrmex Borgmeier ................... Ecitoxenidia Wasmann

3′. Head and pronotum not carinate..................4

4. Pronotum cordiform with anterior margin bisinuate and 2 large circular impressions at base of anterior emargination; host unknown .... Bothronotoxenus tishechkini new genus, ....................................................... new species

4′. Pronotum not cordiform and anterior margin not bisinuate with 2 large circular impressions......................................................................5

5. Paratergites of abdominal segments III-V with prominent tufts of trichomes; occurs with ants in the genera Camponotus Mayr and Formica L.................... Xenodusa Wasmann

5′. Paratergites without tufts of trichomes.........6

6. Occipital suture complete to hypostoma......7

6′. Occipital suture incomplete..........................9

7. Mentum length subequal to width at base; galea and lacinia extremely elongate, galea length greater than 7 times width at base and closer to 10 times width at base ..................... ................................ Myrmedonota Cameron

7′. Mentum length shorter than width at base; galea and lacinia in most instances long but not extremely so, galea length less than 7 times width at base................................................8

8. Labial palpomeres subequal in length; occurs with ants in the genera Crematogaster Lund and Liometopum Mayr ............ Pella Stephens ............ (s. str.) and Platyusa sonomae Casey

8′. Labial palpomere I as long as II and III combined; occurs with ants in the genus Crematogaster ....................... Zyras Stephens

9. Abdominal tergites IV and V with prominent medial tubercles and inner surfaces covered with trichomes; occurs with ant species Tapinoma sessile (Say) ........................... ..................... Myrmoecia Mulsant and Rey

9′. Abdominal tergites IV and V without tubercles....................................................................10

10. Glossa fused; galea and lacinia short, length of galea 3 times width at base ...................11

10′. Glossa not fused; galea and lacinia long, length of galea more than 3 times width at base.........................................................12

11. Integument with microsculpture; body with macrosetae not extremely long and bristlelike; not occurring with ants .......................... ................... Meronera venestula (Erichson)

11′. Integument without microsculpture; body with macrosetae extremely long and bristle-like; not occurring with ants................................... ............................ Apalonia seticornis Casey

12. Eyes large and coarsely faceted, occupying entire lateral margin of head; band of setulate cuticular processes at apex of abdominal tergite VII wide and conspicuous; host unknown ........................ Tetradonia megalops (Casey)

12′. Eyes not so large and coarsely faceted, not occupying entire lateral margin of head; band of setulate cuticular processes at apex of abdominal tergite VII narrow and less conspicuous ......................................................................... 13

13. All antennomeres at least quadrate but most longer than wide; elytra shorter than pronotum and with longitudinal impressions along lateral margin ..................................................14

13′. Some antennomeres transverse; elytra not shorter than pronotum and without longitudinal impressions along lateral margin......15

14. Abdominal tergite VII with small, posteriorly projecting medial spine and segment III with broad, smooth eminence; known from California; ecology unknown ........................ ........................................... Trachyota Casey

14′. Abdominal tergites III and VII without modifications; not known from California; not occurring with ants ................ Drusilla Leach

15. Abdominal tergites without microsculpture; tergites III-VII with macrosetae but virtually no microsetae; antennae not stout in appearance and conspicuously clavate with antennomeral pedicels clearly visible; not occurring with ants ...................................... Xesturida laevis Casey

15′. Abdominal tergites with some microsculpture, at least in form of conspicuous setigerous punctures; tergites III-VII with macrosetae and at least tergite III with microsetae; antennae stout in appearance and at most slightly clavate, antennomeral pedicels visible or not.............16

16. Body flattened, meso- and metasterna not swollen ventrally in lateral view; antennomeral pedicels at least slightly visible; occurs with ants in the genus Neivamyrmex ....................... ............................................ Microdonia Casey

16′. Body not flattened, meso- and metasterna swollen ventrally in lateral view; antennomeral pedicels not visible; occurs with ants in the genus Neivamyrmex ...................... Dinocoryna Casey