Megauchenia quadricollis ( Reitter, 1883 )

Dasgupta, J., Pal, T. K. & Hegde, V. D., 2015, Review of the Megauchenia Macleay of India (Coleoptera: Nitidulidae: Prometopinae), Zootaxa 4058 (4), pp. 551-560 : 558-559

Megauchenia quadricollis ( Reitter, 1883)

Ischaena quadricollis Reitter 1883: 10 .

Megauchenia quadricollis: Grouvelle 1913a: 136 ; Grouvelle 1913b: 100; Jelínek & Audisio 2007: 473.

Diagnosis. Body ( Figs. 21–22 ) rather elongate, subparallel, shiny, reddish brown to blackish. Lateral margin of pronotum almost straight. Elytra with nearly parallel sides, apices sinuate and not uniformly outlined; intervals between elytral striae narrower than the striae; coarsely punctate dorsum with rows of striae on each elytron bearing sparse, short golden and erect setae.

Head transverse, about 1.1x as broad as long, frons feebly depressed; punctation on frons round, distinct, diameter about 0.75x as large as those of vertex, separated by about 1–2 diameters of punctures; punctures on vertex coarser than those on frons, round and distinct; setae on frons indistinct; eyes large and moderately projected, about 0.4x as long as head, outer margin rounded, coarsely facetted, temple short and rounded behind eye; ocular border of head slightly carinate. Antenna about 1.3x as long as head; antennal club about 1.2x as long as broad, club segments closely attached, about 0.3x as long as antenna.

Prothorax sub-quadrate, about as broad as long, anterior margin slightly emarginate; sides sub-parallel, posterior margin bisinuate with a distinct emargination at middle, anterior angles somewhat pointed, posterior angles broadly rounded. Pronotum rather convex, surface distinctly punctate, punctures round or oval, dense, separated on top of pronotal disc by 0.75–1 diameter, setae on disc indistinct.

Scutellar shield transverse, about 1.6x as broad as long, triangular and somewhat rounded apically; punctures and setae indistinct.

Elytra together about 1.8x as long as broad, anterior margin closely fitting with posterior margin of prothorax, humeral angles projected anteriorly, sides subparallel, hardly explanate, apices truncate; punctures slightly smaller than those on pronotum, arranged in ten longitudinal rows, separated by 0.5–0.75 diameters; setae short, erect, posteriorly directed and arranged along striae.

Abdominal tergites almost completely concealed under the elytra, first abdominal ventrite devoid of any punctures, punctures on second and third ventrites elongated and tapering at both ends, punctures on fourth ventrite larger than those of other ventrites, punctures on fifth less elongate and more ovoid; setae moderately long, uniformly arranged, closely appressed to the surface of the abdomen, posteriorly directed.

Ventral side uniformly chestnut-brown; gular region of head with posteriorly converging antennal grooves. Metaventrite with mesocoxal lines reaching almost three-fourths of the metaventral-metanepisternal suture, thereby creating a distinct axillary space.

Aedeagus ( Figs. 25–28 ): Paramere almost uniformly wide along length, slightly constricted near middle; apex truncate, little concave with a long apical seta and few short setae; apical margin of tegmen emarginate. Median lobe broadly elongate with sides nearly subparallel, and an additional apical membranous structure distinctly notched medially, sclerotized apex also distinctly notched; median strut characteristic in shape (see Fig. 28 ).

Measurements (in mm): Total length 3.24–4.20, width of head across eyes 0.69–0.74, length of antenna 0.70– 0.85, length and width of prothorax 1.16–1.28 and 1.25–1.30, length and width of elytra together1.93–2.49 and 1.04–1.34.

Material examined. 11 ex. INDIA, Arunachal Pradesh, Hornbill, 30 km-ne-o-Miao, 1 ex., 16. xii. 1983, S. Biswas; Namdapha WLS, Miao, 1 ex., 01.xii.1982, S. Biswas; Arunachal Pradesh, E. Siang Dist., Nambung, 6 kmo-Boleng, 1 ex., 23.ii.1989, T. K. Pal, ex. under bark; Arunachal Pradesh, Namdapha WLS, 1 ex., 21.iv.1981, S. Biswas; Arunachal Pradesh, L. Dibang Valley Dist., Parbuk, 1 ex., 11.iv.2009, T. K. Pal & party, ex. under bark; Arunachal Pradesh, L. Dibang Valley Dist., Rayang, Roing, 1 ex., 16.iv.2009, T. K. Pal & party, ex. under bark; Arunachal Pradesh, Kobo, 400 ft., Abor Expedition, 3 ex., 01–02.xii.1911, S. Kemp, ex. under bark of rotten wood (Reg. No. 2478/19, 2482/19, 2498/19); Meghalaya, Garo Hill Dist., Barangapara, 1 ex., 23.iv.1991, B. N. Das & party; Meghalaya, Above Tura, Garo hills, 3500–3900 ft., 1 ex., 15.vii.1917 – 30.viii.1917, S. Kemp, ex. under bark.

Distribution. INDIA: Arunachal Pradesh, Meghalaya (new records), Assam; INDONESIA: Java, Sumatra; MYANMAR; TAIWAN.

Figures

FIGURES 19 – 30. 19, 21, 29 (dorsal habitus): 19, Megauchenia angustata (Erichson, 1843); 21, M. quadricollis (Reitter, 1883); 29, M. indica (Grouvelle, 1908); 20, 22, 30 (ventral habitus): 20, M. angustata; 22, M. quadricollis; 30, M. indica. 23 – 28: male genitalia: 23, tegmen and median lobe of M. angustata, microphotograph; 24, median lobe of M. angustata after separating from tegmen, microphotograph; 25, tegmen and median lobe of M. quadricollis, microphotograph; 26, median lobe of M. quadricollis after separating from tegmen, microphotograph; 27, tegmen of M. quadricollis, line drawing; 28, median lobe of M. quadricollis, line drawing.