Bioacoustics of Euligyrus

Description. ( n = 555). Length 24–30 mm . Humeral width 12.5–15.1 mm . Head: Clypeus trapezoidal ( Fig. 1A ). Apical clypeal teeth transverse and widely separated (3 tooth diameters). Ocular canthus rounded; without ventral or dorsal setae. Frons with 2 transverse, high tumescences. Mentum subrectangular; strongly narrowed at apex ( Fig. 2G–H ). Mentum and ligula separate by a suture. Ligula wide; covered with long, dense setae; ligular lobes not fused, with a narrow emargination. Maxillar apical palpomere 1.3 times longer than the second. Maxilla with galea rectangular (2.5 times longer than wide); with 6 teeth ( Fig. 4A ). Mandible tridentate (2 apical and 1 lateral triangular large tooth); apical teeth equal in shape ( Fig. 5A ). Labrum rectangular (2.5 times wider than long); apex straight to slightly bilobed; with long, dense setae. Antenna with 10 antennomeres, club short (1.2 times longer than antennomeres 2–7). Pronotum: Apical marginal bead complete. Apex with a rounded tubercle and an oval to triangular fovea. Elytra: Inner surface of apex with irregular small tubercles. Wings: RA with dense, large peg-like setae on medial ventral region; with peg-like setae on dorsal surface ( Fig. 7A, C ). Edge of RA 3 with dense setae. Abdomen: Apex of tergite IV with irregular granules like scales, not forming lines. Sternite VIII emarginate in males; entire in female. Propygidium without stridulatory area. Venter: Prosternum very wide, convex. Propleura with short, sparse setae on anterior and posterior surface, medial surface glabrous. Apex of prosternal process flat, with a deep sulcus, without dorsal setae. Metepisternum with complete carina; inner surface smooth and glabrous; outer surface homogeneously rugose, glabrous. Metasternum with large, deep, confluent punctures, without setae. Legs: Male protarsus enlarged (tarsomeres 2–4 2 times wider than long, tarsomere 5 1.5 longer than wide); tarsomere 4 with a lateral flat, striate projection ( Fig. 10A ); inner claw bifid ( Fig. 10B ). Protibia tridentate, basal tooth distant from others ( Fig. 11A ). Apical margin of mesotibia and metatibia crenulate ( Fig. 12A, G ). Female genitalia: Subcoxite 1.5 times wider than long. Coxite subquadrate (as long as wide); surface flat ( Fig. 13A ). Subcoxite wider than and as long as coxite. Male genitalia: Phallobase 1.6 times longer than parameres. Parameres without dorsal teeth, with ventral tooth ( Fig. 17A ). Internal sac without copulatory lamella nor lamellar spiny belt; accessory lamella long with an apical brush of setae ( Fig. 21A ).

Diagnosis. Euligyrus can be differentiated from other Pentodontini by the following: frons concave at middle; clypeus trapezoidal, clypeal teeth widely separated ( Fig. 1A ); frontoclypeus with tumescences ( Fig. 1A ); mentum subrectangular; galea with 6 teeth ( Fig. 4A ); pronotum with apical marginal bead complete; pronotal tubercle rounded; fovea deep, oval to triangular; metasternum glabrous; protibia tridentate; protarsus of male enlarged, inner claw wide and bifid ( Fig. 10B ); protarsomere 4 with a lateral flat, striate projection ( Fig. 10A ); internal sac without copulatory lamella nor lamellar spiny belt, with an apical brush of setae ( Fig. 21A ); surface of coxite flat ( Fig. 13A ); and stridulatory apparatus consisting of an area with irregular granules like-scales on apex of sternite IV and apical inner surface of elytra with irregular small tubercles.