Schedolimulus Pasteels & Kistner, 1971

Kanao, Taisuke, Maruyama, Munetoshi & Sakchoowong, Watana, 2011, A new species of Trichopseniini (Coleoptera, Staphylinidae) found with Schedorhinotermes termite (Isoptera, Rhinotermitidae) in Khao Yai National Park, Thailand, Zootaxa 2748, pp. 53-60 : 54-56

Genus Schedolimulus Pasteels & Kistner, 1971

Schedolimulus Pasteels & Kistner, 1971: 367 (original description; type species: Schedolimulus pumilio Pasteels & Kistner, 1971 , by original designation).

Phorilimulus Pasteels & Kistner 1971: 369 (original description; type species: Phorilimulus minutus Pasteels & Kistner, 1971 , by original designation). New synonymy.

Diagnosis. This genus is distinguished from the other limuloid genera of Trichopseniini by the distinctive shape of the antenna in which base of each segment (segments VI–IX) is covered by an apical flange of the preceding segment, and the presence of thick and long spurs on the metatibia. It is most similar to the genus Hamitopsenius Wasmann, 1916 but easily distinguished by the aforementioned characters.

Redescription. Overall shape limuloid ( Fig. 2 ).

Head completely covered by pronotum; head capsule broadly oval when mouthparts excluded and subtriangular when included; anterior border of head capsule slightly grooved to receive antennae, but not deep. Eyes large, prominent. Antennae ( Fig. 3 ) 11-segmented; segment I longer than other segments; segment II small, circular; segment III much smaller than other segments, subquadrate; segments IV small, transverse; segments V–X wider than long, moderately increasing in wide toward segment X; segment XI larger than segments II–X, somewhat circular; base of each segment (segments VI–IX) covered by apical flange of preceding segment. Labrum ( Fig. 4 ) transverse, subquadrate, with 3 setae in lateral area; with several pseudopores between setae. Mandibles ( Figs. 5–6 ) symmetrical, with lateral flange absent, with several pores around middle of dorsal surface; prostheca scarcely visible; with a small tooth at inner margin of mandible. Maxillae ( Fig. 7 ): lacinia narrowed strongly toward apex, with a long seta around middle, 3–5 setae near apex, pointed at apex; galea truncate at apex, densely furnished with setulae; palpus 4-segmented, with a thick seta near apex of segment III. Labium ( Fig. 8 ): palpus 3-segmented; segment I curved near base, dilated apically; segment II elliptical; segment III short, narrowed.

Pronotum ( Fig. 9 ) semicircular. Prosternum reduced in length with long anterolateral processes. Prothoracic coxal cavities extremely small, closed behind by membrane; only long articular process on procoxa articulating with edge of proventral cavity anterolateraly. Mesoventrite ( Fig. 10 ) short, approximately 1/5 length of metaventrites ( Fig. 10 ), with an acute but carinate process between mesothoracic coxal cavities. Mesocoxal cavities margined posteriorly, much larger than metacoxal cavities. Shelves on metaventrites covering metatrochanter and metafemur in repose. Fore leg ( Fig. 12 ) with femur thick, flattened; tibia narrowed, slightly dilated apically. Mid leg ( Fig.13 ) with femur dilated apically; tibia slightly narrowed apically. Hind leg ( Fig. 14 ) with femur widest around middle; tibia dilated apically. Tarsal formula 5-5-5.

Abdomen ( Fig. 2 ) not physogastric, narrowed posteriorly.

Male. Abdominal tergite and sternite VIII ( Figs. 15–16 ) larger than in female; posterior margin of sternite VIII ( Fig. 16 ) slightly sinuate, rounded medially; lateral lobe of tergite IX ( Fig. 17 ) much larger and broader than in female, especially its basal projection twice as long as in female, with long and thick macrosetae around posterior margin. Median lobe of aedeagus ( Fig. 21–22 ) with basal capsule bulbous.

Female. Tergite and sternite VIII ( Figs. 18–19 ) pointed at medial part of posterior margin; lateral lobe of tergite IX ( Fig. 20 ) smaller and narrower posteriorly than in male. Spermatheca ( Fig. 24 ) peanut-shaped.

Discussion. Pasteels and Kistner (1971) described Schedolimulus and Phorilimulus to include a single species each based on a single female and male specimen, respectively. They mentioned that Schedolimulus and Phorilimulus are very similar and share many character states but they are distinguished by the body size, presence/absence of setae on the elytra, and shape of the abdominal tergite IX. Of these characters, the body sizes are actually almost the same in reference to the measurements of each of the type species. Though Pasteels and Kistner (1971) stated that the body size of Schedolimulus pumilio (the type species of Schedolimulus ) is the smallest in the whole subfamily, the pronotal length of S. pumilio indicated in the measurements is larger than that of Phorilimulus minutus (the type species of Phorilimulus ). The presence/absence of setae on the elytra is ambiguous. They noted that the elytra of Schedolimulus are without setae, but in the description and illustrations of S. pumilio indicated the presence of setae. The morphological observation of the present new species, S. komatsui , revealed that the difference in the shape of abdominal tergite IX is merely a sexual difference. Therefore, no pronounced difference between Schedolimulus and Phorilimulus was recognized, and we herein conclude that Phorilimulus should be synonymized with Schedolimulus .

Figures

FIGURES 1 – 2. 1. A carton nest of Schedorhinotermes medioobscurus, 2. Living Schedolimulus komatsui beetle in the termite nest.

FIGURES 3 – 8. Schedolimulus komatsui, mouthparts. 3. Antenna. 4. Labrum. 5 – 6. Mandible. 7. Maxilla. 8. Labium.

FIGURES 9 – 11. Schedolimulus komatsui, thorax. 9. Pronotum. 10. Meso- and metaventrites. 11. Elytra.

FIGURES 12 – 14. Schedolimulus komatsui, legs. 12. Fore leg. 13. Mid leg. 14. Hind leg.

FIGURES 15 – 20. Schedolimulus komatsui, abdominal parts. 15. Male tergite VIII. 16. Male sternite VIII. 17. Male tergite IX. 18. Female tergite VIII. 19. Female sternite VIII. 20. Female tergite IX.

FIGURES 21 – 24. Schedolimulus komastui. 21, Median lobe of aedeagus (holotype), lateral view. 22, Ditto, dorsal view. 23. Paramere (holotype). 24. Spermatheca.