Sundapyrochroa Young, 2014

Young, Daniel K., 2014, Sundapyrochroa: A new genus of Fire-Colored Beetles (Coleoptera: Pyrochroidae: Pyrochroinae) from the Sunda Shelf, with a key to the three species, Insecta Mundi 2014 (341), pp. 1-18 : 2-4

Sundapyrochroa Young , genus novum

( Figures 1–21 )

Type species: Schizotus sumatrensis Pic, 1906 , by present designation.

Description of adult male. (habitus, Fig. 1 , 4–5 , 9–10 ) With general characters of Coleoptera : Polyphaga: Cucujoidea (sensu Crowson 1955). Heteromerous (sensu Crowson 1955): maxillae 2-lobed; tarsal formula 5–5–4; prothoracic coxae conical, prominent and projecting, trochanters of heteromeroid type (sensu Crowson 1955: fig. 106); genitalia of heteromeroid type, with tegmen (= parameres + basal piece) oriented dorsad median lobe.

Head. Cranium ( Fig. 7 , 11 ) with genae well developed, subrectangular behind compound eyes, thence abruptly constricted, forming conspicuous cranial “neck”; frontoclypeal suture present, at least as well defined ridge; labrum moderately-sized, transversely rectangulate, bearing marginal setal fringe; anterior margin nearly straight to feebly emarginate mesally. Compound eyes ( Fig. 7 ) emarginate for accommodation of antennal insertions, finely faceted, devoid of setae between the ommatidia. Antennae 11-segmented; antennomeres 1–2 (e.g., Fig. 8–9 , 11 ) distally swollen, antennomere 1 approximately 3X length of antennomere 2, antennomeres 3–10 strongly, finely pectinate, the ramus of each antennomere densely setose; each antenna inserted in a slightly swollen prominence on frons between base of mandible and compound eye. Mandibles ( Fig. 11 ) elongate, symmetrical, conspicuously flattened dorsoventrally, apices bidentate, dorsal surface of each subglabrous, lateral face bearing sparse, short to moderately elongate, antrorsely directed setae. Maxillae each with cardo well developed, articulating distally with triangular basistipes; mediostipes arising from distal adoral aspect of basistipes, giving rise to galea and lacinia, apex of distigalea and adoral surface of lacinia densely tufted with moderately elongate, coarse setae. Maxillary palpifer subglabrous except for several apicoventral, stout, moderately elongate setae and aboral setal fringe. Maxillary palpus ( Fig. 9 ) consisting of 4 segments arising from membranous apex of palpifer, palpomere 1 small, glabrous, palpomere 2 twice the length of 3, palpomere 4 subcultriform, subequal to length of 2; palpomeres 2–4 setose, anterior marginal setal fringe of palpomere 2 especially well developed. Labium: submentum confluent with gular region, surface glabrous posteriorly, isodiametrically microsculptured to rugulose anteriorly; gular sutures and posterior tentorial pits conspicuous, well impressed; mentum distinct, weakly trapezoidal; ligula well sclerotized basally between palpigers, apex setose; labial palpi each consisting of 3 segments, subequal in length, palpomeres 1–2 filiform, palpomere 3 filiform or slightly expanded distally.

Thorax. Prothorax with pronotum ( Fig. 1 , 4–5 , 9–10 ) subquadrate, slightly narrower anteriorly, about as broad as head, disk shallowly, sparsely to moderately coarsely, densely punctulate, densely setose, sides rounded and lacking lateral margins, lacking modified margin anteriorly, posterior margin well developed, deeply impressed, mesal canaliculus present or not; prosternum transverse, surface glabrous to transversely rugulose, sparsely setose; prosternal process short, acute; prothoracic coxal cavities completely open externally and internally. Mesothorax with scutellum small, widest basally, shield-shaped, longer than wide; mesothoracic coxal cavities not closed outwardly by sterna; mesothoracic episterna narrowly contiguous anterad acuminate anterior margin of mesosternum. Metathorax with sternum well developed, convex, longer than wide. Thoracic venter sparsely punctate; vestiture consisting of short to moderately long, mostly retrorse setae. Legs ambulatorial; prothoracic legs with trochantins partially exposed; internal keel of metathoracic coxae elongate; tibial spurs short, stout, simple; tarsi with penultimate segment lobed ventrally; pretarsi consisting of paired claws, each swollen basally, forming an obtusely rounded to weakly dentiform process; empodium strongly reduced. Elytra well developed, covering metathorax and abdomen, subparallel to slightly wider posteriorly; base of elytra distinctly wider than base of pronotum; elytral vestiture consisting of short, dense, semierect setae, elytral setae generally more erect along either side of the nearly obsolete longitudinal costae, thereby slightly enhancing the illusion of longitudinal costae.

Abdomen. Tergites 1–2 essentially lost, 3–6 poorly sclerotized, 7–8 setose and lightly clerotized. Sternites 1–2 absent, 3–8 sclerotized, setose, last visible sternite (= 8 th) widest basally, apex moderately ( Fig. 19 ) to rather deeply ( Fig. 13, 16 ) emarginate mesally, bearing numerous, moderately elongate marginal setae.

Male abdominal terminalia. Sclerites derived from abdominal segments 9–10 retracted within 8 th abdominal segment; 9 th sternite produced ventroanteriorly, forming sclerotized, V-shaped spiculum gastrale; distal margin of tergite 10 broadly rounded. Tegmen ( Fig. 14, 17, 20 ) oriented dorsad median lobe, consisting of stout, well developed, subrectangular basal piece broadly joined to parameres distally. Parameres fused along basal 2/3, thence abruptly, widely separated; distal parameres narrow and subparallel ( Fig. 14, 17 ) or divergent ( Fig. 20 ). Median lobe ( Fig. 15, 18, 20 ) elongate, produced basally into two short ( Fig. 18 ) to elongate ( Fig. 15, 21 ) median struts.

Female. Grossly similar to the male in general habitus ( Fig. 3 , 6 , 12 ). Antennae shorter, far more robust, densely setose, “velvety” in appearance; antennomeres 3–11 pectinate, rami considerably less produced than those of male; elytra slightly wider posteriorly; terminal abdominal sternite with distal margin rounded.

Etymology. Sundapyrochroa is derived from Sunda - in reference to the Sunda Shelf of the Asian continental plate, the Greek root pyro -, meaning fire, and the Greek, - chroa, meaning the skin. The name refers both to the type localities in southeast Asia as well as to the “fire-colored” elytra that typify so many species of pyrochroine Pyrochroidae . The gender of Sundapyrochroa is feminine.

Generic Diagnosis and Remarks. Pyrochroidae : Pyrochroinae - head nearly prognathous, abruptly constricted behind the eyes, forming a conspicuous cranial “neck”; eyes emarginate; antennal flagellum of the male strongly pectinate to flabellate; base of pronotum narrower than basal width of elytra; prothoracic coxal cavities widely open externally and internally; tarsal formula 5–5–4.

The combination of relatively small, dorsally well separated compound eyes (e.g., Fig. 7 ) and lack of visible cranial modifications in males (e.g. Fig. 7 , 11 ), well developed genae posterad the compound eyes, small antennal pedicel, and delicately pectinate antennal antennomeres 3–10 in the males are diagnostic for Sundapyrochroa . Other pyrochroine genera wherein males lack conspicuous cranial modifications include Dendroides Latreille , Pogonocerus Fischer , and Sinodendroides Young. Like Sundapyrochroa , males of these genera also exhibit finely pectinate antennae. Males of Dendroides ( Fig. 22 ) possess compound eyes that are nearly holoptic dorsally; they are well separated dorsally in males of Sinodendroides ( Fig. 23 ) and Sundapyrochroa ( Fig. 1 , 4–5 , 7 , 9–11 ). Males of Pogonocerus have the first antennal flagellomere (= 3 rd antennomere) small, like the pedicel, with antennomeres 4–10 delicately pectinate; the first flagellomere is pectinate in males of Sinodendroides and Sundapyrochroa . Both males and females of Sundapyrochroa exhibit “ribbed” or slightly costate elytra whereas those of Sinodendroides ( Fig. 23 ) have a densely, confusedly punctate or rugulose surface.

The diagnostic male genitalia provide putative synapomorphies for the three known species of Sundapyrochroa ( Fig. 14, 17, 20 ): the parameres are abruptly and widely separated distally, and each is rounded apically. The parameres of Himalapyrochroa Young , Neopyrochroa Blair , Phyllocladus Blair , and Pseudodendroides Blair are also abruptly and widely separated distally. However, in these genera each paramere is produced into an anteriorly directed subapical tooth.

Figures

Figures 1–3. Sundapyrochroa atricolor (Pic). 1) Habitus, adult male, dorsal. 2) Left antenna, lateroventral. 3) Habitus, adult female, dorsal.

Figures 4–6. Sundapyrochroa nigripennis (Pic). 4) Habitus, adult male, dorsal. 5) Habitus, melanic adult male, dorsal. 6) Habitus, adult female, dorsal.

Figures 7–8. Sundapyrochroa nigripennis (Pic). 7) Head, adult male, dorsal. 8) Left antenna, dorsolateral.

Figures 9-10. Sundapyrochroa sumatrensis (Pic), habitus adult male illustrating color variations.

Figures 11–12. Sundapyrochroa sumatrensis (Pic). 11) Head, adult male, dorsal. 12) Habitus, adult female, dorsal.

Figures 13–21. Three species of Sundapyrochroa. 13) S. atricolor (Pic), abdominal sternite eight. 14) S. atricolor (Pic), tegmen, dorsal. 15) S. atricolor (Pic), penis, dorsal. 16) S. nigripennis (Pic), abdominal sternite eight. 17) S. nigripennis (Pic), tegmen, dorsal. 18) S. nigripennis (Pic), penis, dorsal. 19) S. sumatrensis (Pic), abdominal sternite eight. 20) S. sumatrensis (Pic), tegmen, dorsal. 21) S. sumatrensis (Pic), penis, dorsal.

Figures 22–23. Two species of Pyrochroidae. 22) Dendroides canadensis Latreille, habitus adult male, dorsal. 23) Sinodendroides chinensis Young, habitus adult male, dorsal.