Helonoton mexicanum 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 mexicanum Lord and Ivie , new species

( Figs. 12 , 23 )

Diagnosis. This species most closely resembles H. ashei , but differs in the central ridge on the pronotal disc more strongly and evenly carinate, both pairs of mid-lateral pronotal tubercles more developed and carinate, the posterior pair larger than anterior pair, elytral interstrial interval 1 (sutural) carinate, variously interrupted in the basal half, basal elytral carinae of interval 7 not interrupted, most elytral tubercles developed into short carinae, and epipleuron continuing nearly to elytral apex.

Description. Size small (TL = 3.0 mm), body oval-elongate (TL/EW = 2.2), subparallel; bicolored, dark brown with light brown/golden patches (difficult to see if specimen is encrusted); habitus as in Fig. 12 . Head: Elongate (HW = 0.6 mm), broadest at eyes, 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 elongate (PW = 1.1 mm, PL = 0.9 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 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 pattern of ridges and depressed areas; central portion with strongly depressed area, bordered laterally by sinuate ridge, ridge strongly carinate throughout; central portion bordered anteriorly by paired, short, parallel ridges that become confluent with anterior margin and bordered basally by distinct paired, baso-laterally directed ridges that end before posterior margin creating subtriangular baso-medial depression. Pair of strongly raised, short carinae present between lateral pronotal margin and basal ½ of central sinuate tuberculate ridge, as well as smaller pair present between lateral pronotal margin and anterior portion of central sinuate tuberculate ridge. Procoxal cavities broadly open externally. Mesothorax: Scutellum well-developed, visible, oval, not transverse. Elytra: Elongate, parallel-sided, widest at middle (EL = 2.1 mm, EW = 1.4 mm, EL/EW = 1.5). Surface with series of well-defined, short carinae. Sutural stria raised and carinate, variously interrupted in basal half, distinctly diverging antero-laterally to form scutellary striole. Scutellary striole present, but interrupted by small tubercle mid-way between end of interrupted sutural stria and elytral base. Each elytral base with 4 elongate carinae; 1 st at base of elytral interstrial interval 3, raised, elongate, not distinctly swollen posteriorly; 2 nd at base of interval 5, ⅔ length of carina on interval 3; 3 rd at base of interval 7, beginning at humeral angle and extending towards apex, 2X as long as carina on interval 5; 4 th on interval 8, on humeral angle, ⅓ as long as carina on interval 7. Interval 9 carinate, variously interrupted. 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, narrowing apically, continuing nearly to elytral apex. Metaventrite: Longer than abdominal ventrite I, with paired sinuate grooves posteriad and bordering mesocoxae, also with paired, slightly curved grooves anteriad and bordering metacoxae. Discrimen short, extending only to basal ⅓ of metaventrite, strongly impressed between and anteriad metacoxae. Metacoxae transverse, narrowly separated. Metendosternite of fully winged form as in Fig. 2g (see genusgroup description). Abdomen: Intercoxal process of abdominal ventrite I triangular, apex acute. In males, ventrites III and IV with large, smooth, transverse-oval patches in lateral areas; patches occupy most of ventrite IV. Metathoracic wing: Fully developed.

Distribution. Mexico ( Fig. 23 ).

Biology. Specimens were collected from a dead branch on the ground and under Quercus L. ( Fagaceae ) bark in a mesophyllic forest.

Etymology. Named after the home country of this species, Mexico.

Type Material. 11 specimens. Holotype (pointed, MAIC): MEXICO, Hgo. Hwy.105; 2.7mi. N.Tlanchinol; 5000’ 10May1983 CW.&; L.O’ Brien&GBMarshall. Paratype (pointed, MAIC): MEXICO: Tamps., Mun.; Gomez Farias, La; Gloria, 1400m., 17-; III-1988, P. Kovarik / collected under: Quercus bark / mesophylic forest; Quercus, Liquidambar ,; Magnolia, Acer,; Carya, Podocarpus, etc. Paratype, male (pointed, partially dissected, genitalia and abdomen in glycerine in genitalia vial pinned underneath specimen, MAIC): MEXICO, Hgo.Hwy.105; 2.7mi. N.Tlanchinol; 5000’ 17June 1983 CW.&; L.O’ Brien&GBMarshall. Paratype (pointed, MAIC): MEXICO,Hgo.Hwy.105; 2.7mi. N.Tlanchinol; 5000’ 16June1983 CW.&; L.O’ Brien &GBMarshall. Paratypes (3 pointed, MAIC): MEXICO,Hgo.Hwy.105; 2.7mi. N.Tlanchinol; 5000’ 15June1983 CW.&; L.O’ Brien&GBMarshall. Paratype (pointed, MAIC): MEXICO,Hgo.Hwy.105; 2.7mi. N.Tlanchinol; 5000’ 2Aug.1982 CW.&; L. O’ Brien&G. Wibmer. Paratypes (3 pointed, MAIC): MEXICO,Hgo.Hwy.105; 2.7mi. N.Tlanchinol; 5000’ 10May1983 CW.&; L.O’ Brien&GB Marshall / from dead branch; on ground.

Figures

Figs. 9–12. Helonoton species, dorsal habitus. 9) H. chiriqui, holotype (KSEM); 10) H. costaricense, holotype

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

Fig. 2. Helonoton costaricense. 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.