Globotrichus Lord and Ivie, 2016

Lord, Nathan P. & Ivie, Michael A., 2016, Several New Genera and Species of New World Synchitini (Coleoptera: Zopheridae: Colydiinae), The Coleopterists Bulletin 70 (4), pp. 715-753 : 715-753

Globotrichus Lord and Ivie , new genus ( Figs. 1 , 5 , 21 )

Type Species. Globotrichus harti Lord and Ivie , new species.

Etymology. The name invokes an image from the English “globose” combined to rhyme with the name of the related Neotrichus Sharp, 1886 , referring to its hemispherical shape and stout, erect setae. Masculine.

Diagnosis. The genus is most similar to the cosmopolitan genus Neotrichus in the tarsi appearing 3-3-3, but they are actually 4-4-4 due to a reduced first tarsomere, and the stout, bristle-like setae scattered over the body. It differs in the less elongate, more globose body; pronotum without mid-lateral secretory pore; lyriform pronotum; distinct antennal groove beneath the eye; and less flattened head with large, coarsely facetted, hemispherical eyes.

Description. Small (TL = 2.7 mm), body convex-oval (TL/EW = 2.2), rounded; dark brown to black; habitus as in Fig. 5 . Dorsal surface granulose; vestiture consisting of short, stout, bristle-like setae. Ventral surface rugose, with round to irregularly shaped (vermiculate) punctures; vestiture consisting of short, stout, bristle-like setae (shorter than setae on dorsal surface). Head: Subquadrate (HW = 0.5 mm), broadest at eyes ( Fig. 1a ); lacking temples; head not abruptly constricted behind eyes; apical margin truncate; apico-lateral margins swollen, raised anteriad eyes. Dorsal surface with large, round granules of varying size, each bearing a short, stout, bristle-like seta. Eyes large, hemispherical; strongly protuberant; facets large, interfacetal setae present, stout, slightly thinner than setae on head. Antennal groove distinct, short, smooth, extending to about middle of eye. Gena rounded, not inflexed. Subgenal brace well-developed, broad, bearing several short, thickened, scale-like setae. Antennae: Short, subequal to length of head, extending slightly past anterior margin of pronotum; 11- segmented, ending in an abrupt 2-segmented club ( Fig. 1d ). Scape asymmetrical, barrelshaped with narrow, cylindrical lateral extension near base that inserts into head capsule; pedicel quadrate, half as long as scape; antennomere 3 narrow basally and slightly and gradually expanding apically, as long as or slightly longer than 4+5; antennomeres 4–9 short, increasingly shorter and wider; antennomeres 10–11 enlarged, forming an abrupt club; antennomere 10 transverse, symmetrical, widening to apical ⅓ and slightly narrowing, then truncate at apex; antennomere 11 transverse-oval. Scape and pedicel with few short, stout, bristle-like setae; antennomeres 3–9 each with medial ring of fine setae, setae shorter than length of segment; antennomere 10 with medial ring of setae and with dense field of short pubescence at apex; antennomere 11 more densely setose on entire surface, apex with dense pubescence. Mouthparts: Labrum short, transverse, anterior margin slightly curved; apico-lateral angles rounded, fringed with few sparse, medially directed setae. Mandibles symmetrical, with distinct mola and membranous prostheca ( Fig. 1f ); apex bidentate. Maxillary palpi 4-segmented, terminal palpomere fusiform ( Fig. 1c ); galea and lacinia of normal form, bearing numerous stout setae apically, lacking spines; mentum transverse, rugose, bearing several short, thickened, scalelike setae, anterior margin straight ( Fig. 1b ); ligula transverse, with central triangularly raised portion between insertions of palpi, antero-lateral corners of ligula produced into thin lobes, each lobe bearing several setae; labial palpi 3-segmented, terminal palpomere fusiform, widest at basal ⅓; labial palpi inserted ventrally. Prothorax: Transverse, widest at middle (PW = 1.1 mm, PL = 0.8 mm, PL/PW = 0.7). Lateral pronotal margins lyriform, narrowing slightly at basal half, distinctly expanded in apical half ( Figs. 1h , 5 ); lateral margins denticulate, each denticle bearing short, stout, bristle-like seta; anterior angles distinct, angulate, projecting, reaching level of posterior margin of eye. Anterior margin arcuate to slightly sinuate medially, depressed/ notched/excavated just inside of anterior angles. Posterior margin arcuate, fringed with row of short, fine setae, directed posterior-medially; posterior angles indistinct. Disc granulate/microtuberculate, with several subtly raised and depressed areas ( Fig. 5 ). Surface granulose, covered with subequal round to ovoid granules, each bearing short, stout, bristle-like seta. Prosternum/hypomeron with subtle depression forming cavity for reception of antenna, depression rugose medially and impunctate/smooth laterally. Anterior margin of prosternum fringed with row of short, fine setae, directed anteriorly. Prosternal process nearly parallel-sided, slightly narrowing anteriorly ( Fig. 1h ), apex slightly emarginated medially; prosternal process slightly raised; procoxae countersunk, prosternal process extending ventrad and concealing inner ¼ of procoxae from view. Procoxa round, externally separated by greater than width of visible portion of procoxa, internally very narrowly separated. Hypomeral extension angulate, extending nearly to prosternal process; procoxal cavity narrowly open externally; posterior margin fringed with row of short, fine setae, directed posterio-medially. Mesothorax: Scutellum welldeveloped, visible, transverse-oval. Mesoventrite: Short, transverse ( Fig. 1i ); surface bearing sparse, short, stout, bristle-like setae and irregularly shaped punctures; apical margin straight; mesoventral process parallel-sided, apex slightly emarginate medially. Mesocoxal cavities broadly closed, mesocoxal separation narrow, about ⅓ width of coxal diameter (visible coxa, not accounting for countersunk portion). Elytra: Parallel-sided ( Fig. 5 ), widest at apical ⅓ (EL = 1.9 mm, EW = 1.2 mm, EL/EW = 1.6). Humeral angles well-developed, rounded. Anterior margin nearly straight, slightly concave at middle; lateral margins not explanate. Elytral apex broadly rounded; sutural carina not diverging antero-laterally, scutellary striole absent. With 9 punctate striae (may be difficult to discern in dirty specimens, best observed by viewing ventral elytral surface in cleared specimens); vestiture consisting of stout, bristle-like setae inserted on pustules on raised ribs between strial punctures. Surface variably tuberculate on interstriae 3, 5, and 7; tubercles may be absent, small or obvious, covered with tufts of setae or rubbed, often not symmetrical from left to right elytron; no pattern related to size or sex noted in the limited material available. Epipleuron present, weakly defined, gradually narrowing, ending at level of abdominal ventrite III. Metaventrite: Moderate in length, slightly shorter than or about as long as abdominal ventrites I–III ( Fig. 1i ); convex, slightly more swollen on either side of midline; surface bearing sparse, short, stout, bristle-like setae and irregularly shaped punctures; with paired, slightly sinuate grooves bordering metacoxae anteriorly. Discrimen present, weak, slightly impressed, extending to about middle of metaventrite. Metacoxae transverse, narrowly separated, separation about ⅓ of coxal diameter. Metendosternite as in Fig. 1g . Furca short, wide; laminae reduced; lateral furcal arms long, narrowing apically; anterior tendons narrowly separated, arising from short, rounded projections near furcal midline; metafurcal ventral flange present, not strongly projecting ventrally. Abdomen: Ventrites I–III connate, subequal in length ( Fig. 1j ). Intercoxal process acute; ventrite V rounded at apex, lacking preapical groove; surface of all ventrites bearing sparse, short, stout, bristle-like setae and irregularly shaped punctures. Legs: Trochanters present, visible, trochantero-femoral attachment strongly oblique ( Fig. 1e ); femora simple, straight with short, stout, bristle-like setae; tibiae simple, straight with short, stout, bristle-like setae; tibial apex ringed with long, fine, hair-like setae; tarsi appearing 3-3-3, but actually 4-4-4; tarsomere 1 greatly reduced, shorter than 2, tarsomere 3 about as long as 1–2; tarsomere 4 elongate, 2.5X length of 1–3 combined, slightly expanded apically, setation sparse, consisting of long, thin, hair-like setae; tarsal claws simple. Metathoracic wing: Fully developed. Aedeagus: Typical tenebrionoidtype ( Fig. 1k–l ); tegmen lying dorsad medial lobe; anteroventral edge of segment IX with spiculum gastrale, anterior portion of phallobase broadly rounded, narrowed apically to point; parameres narrow, elongate, individually fused to base of phallobase, extending beyond apex of phallobase; median lobe expanded ventrally at middle, tapering to apex, resting within sheath-like tegmen. Ovipositor: Not examined.

Distribution. Panama, Costa Rica, Bolivia, Brazil.

Biology. Given the collection methods (see species account below), it is likely that members of Globotrichus are generalist detritovores and fungivores like many other members of the soildwelling Synchitini .

Comments. Ten of the 14 known specimens of Globotrichus are included in the type series of G. harti , with the type series limited to those specimens from Costa Rica and Panama. The other specimens, from Amazonian Bolivia and southeastern Brazil, probably represent different species, but insufficient material is available for description at this time. It is hoped more material is identified from unsorted material after this paper makes the identity known.

Figures

Fig. 1. Globotrichus harti. a) Head, ventral view, b) Labium, ventral view, c) Maxilla, ventral view, d) Antenna, e) Fore leg, f) Mandible, ventral view, g) Metendosternite, ventral view, h) Prothorax, ventral view, i) Pterothorax, ventral view, j) Abdominal ventrites I–V, ventral view, k) Aedeagus, dorsal view, l) Aedeagus, lateral view.

Figs. 5–8. Synchitine Colydiinae, dorsal habitus. 5) Globotrichus harti, paratype (KSEM); 6) Helonoton amistad, holotype (CNCI); 7) Helonoton ashei, paratype (CMNC); 8) Helonoton bituberculatum, holotype (CMNC). Scale bars = 1 mm.

Figs. 21–22. Distribution maps. 21) Globotrichus harti in Costa Rica and Panama (Bolivian and Brazilian specimens not shown, see text), Paxillobitoma clinei in French Guiana (Bolivian, Brazilian, and Panamanian specimens not shown, see text), and Rapthius peruvianus in Peru; 22) Slipinskius chilensis in Chile.