Helonoton bituberculatum 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

Helonoton bituberculatum Lord and Ivie , new species

( Figs. 8 , 23 )

Diagnosis. This species most closely resembles H. ashei , but differs in the smaller size and more convex-oval body shape, unicolorous elytra, reduced number of basal elytral carinae, scutellary striole not apparent, and distinctly shorter metaventrite.

Description. Size small (TL = 2.2 mm), body convex-oval (TL/EW = 1.9), subparallel; unicolorous, light brown; habitus as in Fig. 8 . Head: Elongate (HW = 0.5 mm), not constricted behind eyes. Antennae: 11-segmented, ending in an abrupt, 2-segmented club; antennomeres 10–11 forming distinct club, antennomere 10 transverse, trapezoidal to slightly asymmetrical, narrowest at base; antennomere 11 truncate at base, transverse, rounded apically. Prothorax: Pronotum subquadrate (PW = 1.0 mm, PL = 0.8 mm, PL/PW = 0.8), widest at apical ⅓, narrowest at base. Lateral margins of pronotum sinuate, widening apically, anterior ⅓ produced into strong arcuate lobe, posterior ⅔ of lateral pronotal margin with small lobe or denticle; anterior angles distinct, slightly projecting forward to about level of anterior margin; posterior angles present, small. Pronotal disc with complex patterns of ridges and depressed areas; central portion with strongly depressed area, bordered laterally by sinuate ridge, ridge interrupted to form extremely strong tubercles in posterior ½ and paired, short, parallel ridges anteriorly that become confluent with anterior margin; central portion bordered basally by subtle, paired, basolaterally directed ridges that end before posterior margin, creating subtriangular baso-medial depression. Pair of ovoid, mid-lateral tubercles present between lateral pronotal margin and basal half of central sinuate tuberculate ridge, as well as subequal pair present between lateral pronotal margin and anterior portion of central sinuate tuberculate ridge. Procoxal cavities broadly open externally. Mesothorax: Scutellum welldeveloped, visible, oval, slightly transverse. Elytra: Elongate-oval, widest at middle (EL = 1.4 mm, EW = 1.2 mm, EL/EW = 1.2). Surface with series of well-defined tubercles and shallow carinae/ridges. Sutural stria raised and carinate, variously interrupted in basal 1/2, distinctly diverging antero-laterally to form scutellary striole. Scutellary striole present, but interrupted by small tubercle near end of interrupted sutural stria. Each elytral base with an elongate carina, at base of interstrial interval 3, raised, elongate, not distinctly swollen posteriorly. Interval 9 with 3 evenly separated, subequal tubercles. Remaining tubercles on middle portion of elytra small and round to elongate-oval, of variable sizes. Carinae present on elytral declivity, short, not extending nearly to apex. Epipleuron present, weakly defined, incomplete to apex, ending at junction of abdominal ventrites IV and V. Metaventrite: Slightly shorter than or about as long as length of abdominal ventrite I; with paired sinuate grooves directly posteriad and bordering mesocoxae, also with paired, slightly curved grooves directly anteriad and bordering metacoxae. Discrimen short, reduced to an ovoid impressed between and anteriad metacoxae. Metacoxae transverse, moderately separated. Metendosternite of apterous form (see genusgroup description). Abdomen: Intercoxal process of abdominal ventrite I triangular, apex broadly rounded, not acute. In males, ventrites III and IV with large, smooth, transverse-oval patches in lateral areas. Metathoracic wing: Absent.

Distribution. Honduras ( Fig. 23 ).

Biology. Of the two specimens known, one was collected beating; the other was collected by berlese of Liquidambar L. ( Altingiaceae ) forest litter.

Etymology. Named after the two strongly raised central tubercles on the pronotal disc, a diagnostic character for this species.

Type Material. 2 specimens. Holotype, male (pointed, partially dissected, genitalia and abdomen in glycerine in genitalia vial pinned underneath specimen, CMNC): HONDURAS: CORTES, P. N.; Cusuco, 18.7km. N. Cofradia,; 5.4km. W. Buenos Aires; Cerro Jilinco , 1650m, 26.VIII.; 1994-224 A. R. Anderson; liquidambar forest litter berlese . Paratype, female (pointed, partially dissected, genitalia and abdomen in glycerine in genitalia vial pinned underneath specimen, CMNC): HONDURAS: CORTES, P. N.; Cusuco, 18.7km. N. Cofradia,; 5.4km. W. Buenos Aires, Cerro; Jilinco , 1650m, 26.VIII.1994 -; 225, R. Anderson, beating .

Figures

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. 23–24. Distribution maps of Helonoton species. 23) Species in Mexico, Guatemala, El Salvador, and Honduras;