Helonoton pascoei ( Sharp, 1894 ) Lord & 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 pascoei ( Sharp, 1894) , new combination

( Figs. 13 , 23 )

Bitoma pascoei Sharp 1894: 461 , tab. XIV, fig. 21. New combination.

Diagnosis. Helonoton pascoei most closely resembles H. tatumbla in general appearance and by having the scutellary striole interrupted by a small tubercle, but differs in the 2-segmented antennal club, head without distinct temples behind the eyes, presence of the anterior pair of pronotal mid-lateral tubercles, and a Mexican distribution. It also resembles H. chiriqui , but can be diagnosed by the interrupted scutellary striole, more elongate elytral tubercles, more strongly raised central carina of the pronotal disc, and Mexican distribution.

Description. Size small (TL = 3.6 mm), body oval-elongate (TL/EW = 2.1), subparallel; light brown; habitus as in Fig. 13 . Head: Elongate (HW = 0.7 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 elongate

15) H. tatumbla , paratype ( CDFA); 16) H. tico , holotype ( KSEM). Scale bars = 1 mm .

(PW = 1.4 mm, PL = 1.0 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 straight, lacking lobes/denticles; 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 more strongly tuberculate in posterior ½, nearly appearing as separate tubercles; central portion bordered anteriorly by paired, short, parallel ridges that become confluent with anterior margin and bordered basally by subtle, paired, baso-laterally directed ridges that end before posterior margin, creating subtriangular baso-medial depression. Pair of strongly raised, ovoid, mid-lateral tubercles present between lateral pronotal margin and basal half 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 = 2.6 mm, EW = 1.7 mm, EL/EW = 1.5). Surface with series of well-defined tubercles and shallow carinae/ridges. Sutural stria raised, beaded, ending before posterior of carina on interstrial interval 3. Scutellary striole present, but interrupted by small tubercle mid-way between end of 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, ½ as long as carina on interval 3; 3 rd at base of interval 7, beginning at humeral angle and extending towards apex, ⅓ longer carina on interval 3; 4 th on interval 8, on humeral angle, shorter than carina on interval 5. Interval 9 with three evenly separated tubercles, middle tubercle carinate, longer than anterior and posterior 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: Longer than 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, 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 genus-group 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. Metathoracic wing: Fully developed.

Distribution. Mexico ( Fig. 23 ).

Biology. One specimen was collected under oak bark.

Comments. In his description, Sharp (1894) remarks “Notwithstanding the fact that this insect is so totally different from its more normal congeners, the structural characters that I can see in the single example at my disposal do not display any corresponding dissimilarity.” Sharp also remarks that “It somewhat resembles in form the largest examples of Illestus terrenus, Pascoe. ..” [= Lasconotus terrenus (Pascoe) ], which is true, but only in a superficial context. It is interesting to note that although this is the oldest name, it is the species known from the fewest specimens.

Type Material. 1 specimen. Holotype, female (card-mounted, BMNH): [written at base of card in Sharp’ s hand] Bitoma pascoei ; Type D.S.; Huitzo.; Höge. / [round label with red border] Type / Sp. figured. / Huitzo,; Oaxaca.; Höge. / B.C.A., Col., II, (1).; Bitoma .

Additional Material Eamined. 1 specimen. Male (1 pointed, partially dissected, genitalia and abdomen in glycerine in genitalia vial pinned underneath specimen, MAIC): MEXICO: Oaxaca; 27.3 mi N Ixtlan; de Juarez 9200’; VIII-10-18- 1973 / under; oak bark; A. Newton / “ Bitoma ”; pascoei Sharp ; det. S.A. Ślipiński 86 [abdomen and genitalia dissected by NPL, in glycerine in genitalia vial pinned beneath specimen] .

Figures

Figs. 13–16. Helonoton species, dorsal habitus. 13) H. pascoei (MAIC); 14) H. pustulosum, holotype (FSCA);

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.