Neanopidium mexicanum Dajoz, 1975

Aloquio, Sergio & Lopes-Andrade, Cristiano, 2019, Complementary description of Neanopidium mexicanum (Coleoptera: Tenebrionidae: Anopidiina), Iheringia, Série Zoologia (e 2019002) 109, pp. 1-5 : 2

Neanopidium mexicanum Dajoz, 1975

( Figs 1 – 12 )

Material examined. Six specimens (one male, one female and four undetermined, FMNH), labeled: “ MEX.: OAX.; 32mi S Valle Nacional , 7000’ 22.v.1971 S. Peck Ber 205, leaf litter” .

Complementary description.Males with body( Figs 1-3 ) strongly convex, somewhat globose, shiny, glabrous except for labrum, legs, antennae and head; dorsum and venter dark reddish brown; mouthparts, legs and antennae dark golden yellow. Head coarsely punctate; punctures closest to each other in occipital region; clypeal suture barely discernible. Mandibles ( Figs 4, 5 ) asymmetrical; outer edge with row of setae; mola and prostheca developed; prostheca membranous; bidentate. Maxillae ( Fig. 6 ) with visible separation between galea and lacinia. Lacinia subcYlindrical, With lOng, stiff setae apicallY. Galea trapeZOidal, apex cOncaVe, With lOng, stiff setae. Maxillary palpi with four palpomeres; apical palpomere lanceolate; apex narrow, with small, rounded sensorial patch; area before apex with patch of small, spatulate sensillae ( Fig. 7 , arrow). Cardo semicircular. Mentum subquadrate. Labial palpi with three palpomeres; apical palpomere lanceolate, acute apex with rounded sensorial patch. Ligula pentagOnal, With acute apex cOVered With shOrt, stiff setae. Hypopharynx ( Fig. 6 ) membranous, with a triangular sclerite ( Fig. 6 , arrow). Eyes absent. Antennae ( Fig. 8 ) with 7 antennomeres (club counted as single antennomere, but seems to be fusion of three antennomeres with no visible suture between them, even in slide preparation); stellate sensoria (sensillifers; compound, multi-pronged sensoria sensu LAWRENCE et al., 2011) in inner and outer edges and apex of club; antennal insertions concealed in dorsal view by genal margins.

PrOnOtum finelY punctate, cOmparatiVelY finer than cephalic punctation; transverse, about 1.5x as wide as long, widest posteriorly and longest at middle; lateral edges explanate from anterior 1/3 to posterior edge; posterior angles acute; posterior portion not sinuous. Prosternal process large, about as wide as procoxa, subparallel-sided; apex truncate. Elytra about as long as wide in dorsal view, and about 1.8x as long as pronotum, wider at middle; epipleura with an indentation close to ventrite III, ending abruptly at beginning of last abdominal ventrite; punctation sparse, as coarse as on head. Metendosternite ( Fig. 9 ) with short and narrow stalk, and long slender furcal arms; apex of furcal arms widened. Hind wings absent. Tibiae simple, pubescent, bearing row of spines apically, with two spines slightly longer in inner angle. Tarsal formula 4-4-4.

Abdomen With fiVe Ventrites; Ventrites I–III cOnnate, ventrites IV and V free; membrane visible between ventrites III– IV and IV – V; ventrites subparallel-sided until middle of ventrite III, than slightly enlarging to ventrite IV, narrowing to apex. Aedeagus ( Fig. 10 ) with basale about 1.5x as long as apicale; apicale subtriangular, about twice as long as wide, widest at base; basale about 3x as long as wide, widest at middle, curved ventrally at basal 1/3; penis about as long as basale, lanceolate; ejaculatory duct about 2x as long as aedeagus. Spicullum gastrale ( Fig. 11 ) horseshoe-shaped, enlarged at base of arms, each arm bearing one long seta basally.

Females similar to males in exposed features. Terminalia ( Fig. 12 ) with bursa copulatrix about as long as gonocoxites together; bursa copulatrix with apical balloonshaped expansion, about as long as bursa; window of bursa and spermatheca absent; accessory gland tubular, about as long as gonocoxites together; ovipositor subquadrate, about as long as wide; paraprocts about 1/2 as long as gonocoxites together, bearing pair of baculi; baculi of gonocoxites oblique to baculi of paraprocts; gonocoxites ventrally divided into four lobes of subequal lengths; each apical lobe with long, slender gonostylus, surrounded by long setae; gonostyli as long as apical lobe of gonocoxites.

Variation. Measurements (in mm; n = 6): TL = 2.44–2.47 (2.46 ± 0.01), PL = 0.78–0.81 (0.79 ± 0.01), PW = 1.25–1.28 (1.26 ± 0.01), EL = 1.34–1.50 (1.41 ± 0.07), EW = 1.47–1.56 (1.50 ± 0.04), GD = 1.09–1.19 (1.14 ± 0.04). Ratios: GD/EW = 0.74–0.77 (0.76 ± 0.01), TL/EW = 1.58–1.68 (1.64 ± 0.04).

Comments. Neanopidium mexicanum differs frOm other species in the genus in being at least 2.4 mm long, with glabrous pronotum and elytra, elongate antennomeres I– IV, fine and sparse prOnOtal punctatiOn that is cOmparatiVelY finer than cephalic punctation, and lateral edges of pronotum not sinuous. The length range of N. similis and N. pubescens overlaps a little, but in the former the pronotal punctation is coarser than the cephalic punctation, and the lateral edges of pronotum are sinuous posteriorly. Neanopidium pubescens is conspicuously pubescent dorsally. The largest known N. lawrencei reachs 2.35 mm, very close to the smallest N. mexicanum , which are 2.4 mm long, but the former is easily discernable by its conspicuous dorsal pubescence. We failed to release specimens from the paper they were glued, eVen after using a mOdified Barber’s fluid (fOrmula of STÜBEN & LINSENMAIR, 2009). These specimens are from the same locality as the holotype and paratypes, collected only one day after some of the paratypes. It is important to note that the measurements of the studied series are within the variation mentioned in its original description, but with a comparatively smaller range, given the fewer specimens studied by us.

Figures

Figs 1-7. Neanopidium mexicanum Dajoz, 1975, habitus: 1, dorsal; 2, ventral; 3, lateral; mandibles: 4, left; 5, right; 6, labrum, maxillae and sclerite of hypopharynx (arrow); 7, detail of apical maxillary palpomere showing spatulate setae (arrow). Scale bars: 0.5 mm (Figs 1-3), 0.1 mm (Figs 4-7).

Figs 8-12. Neanopidium mexicanum Dajoz, 1975; 8, antenna; 9, metendosternite; 10, aedeagus in ventral view; 11, spicullum gastrale; 12, female abdominal terminalia. Scale bars: 0.1 mm.