Pseudopyrochroa carinifrons Kôno

Young, Daniel K., Hsiao, Yun, Liang, Wei-Ren & Lee, Chi-Feng, 2016, Descriptions of the mature larvae for two species of Pseudopyrochroa from Taiwan (Coleoptera: Pyrochroidae: Pyrochroinae), with notes on their natural history, Zootaxa 4061 (5), pp. 585-595 : 586-590

Pseudopyrochroa carinifrons Kôno

( Figures 1 –7, 16–19)

Description of mature larva. Mature larvae ( Figs. 1 , 17–18; n = 2) attain lengths (mesal labral apex to apices of urogomphi) of 22.0– 26.5 mm and widths (across widest portion of eighth abdominal segment) of 3.8–4.0 mm. Body orthosomatic with sides subparallel, moderately sclerotized except much of cranium, mandibles, and urogomphal plate more heavily sclerotized; body vestiture consisting of short to moderately elongate, scattered setae. Thoracic and abdominal terga 1–7 and 9 lacking parabasal ridges; 8th abdominal tergum with weakly formed parabasal ridge. Head and body creamy-yellowish to amber, melanization much darker in areas of heavy sclerotization such as tips of mandibles, urogomphi, urogomphal lip and urogomphal pits.

Head: Prognathous, flattened, exserted from prothorax. Epicranial suture lyriform with stem short, frontal arms complete nearly to antennal insertions; endocarinae absent. Free, symmetrical labrum anterad fused frontoclypeal region. Stemmata on each side 4, in 2 groups of 2, lower pair parallel with antennal insertions. Antennal insertions fully exposed, antennae moderately elongate, filiform, 3-segmented, 1st antennomere 0.1–0.2 longer than antennomeres 2 and 3, sensorium of segment 2 small, conical, 3rd antennomere narrower than antennomeres 1–2, acutely rounded apically. Mouthparts retracted. Mandibles heavily sclerotized, asymmetrical, molar area of mandibles well developed, left mandible bearing a prominent molar tooth; apex of right mandible distinctly tridentate, that of left mandible bidentate; dorsal mandibular surface basad the molae with microtrichial FIGURES 5–7. Pseudopyrochroa carinifrons Kôno , larva: Fig. 5: urogomphal plate, dorsal view; Fig. 6: abdominal segments 8- 10, ventral view; Fig. 7: distal urogomphal plate: urogomphal pits, ventral view.

complex well developed. Maxillae ( Fig. 2 ) each with 1-segmented cardo which is diagonally folded upward upon itself toward the stipes and thus appearing 2-segmented, a well developed, undivided, pad-like maxillary articulating area; ventral surface of stipes with dense row of stout setae mesad palpifer along adoral margin ( Figs. 2–4 ); galea and lacinia fused to form maxillary mala; mala bearing stout apical and adoral setae and spinose-dentiform uncus at apico-adoral margin ( Fig. 4 ); 3-segmented, filiform maxillary palpus, 2nd palpomere about 2X length of first, 3rd palpomere subequal in length to that of 2nd, 3rd palpomere tapering distally, acutely rounded apically. Labium ( Figs. 2, 4 ) with mentum ovate-subquadrate, submentum elongate with sides shallowly sinuate basally, apical margin slightly more heavily sclerotized, convexly rounded; ligula well developed, elongate; each labial palpus short, 2-segmented. Hypopharyngeal sclerome ( Fig. 3 ) well sclerotized, molar-like; proximal region of hypopharynx with complex setal brushes. Hypostomal rods ( Fig. 2 ) well developed, divergent; gular sutures separate.

Thorax and Abdomen: Thoracic segmentation well developed, sides parallel; cervicosternum divided into three plates. Legs well developed, moderately short, 5-segmented including tarsungulus, vestiture consisting of sparse, short setae; coxae large, separated by 2–3 coxal diameters. Abdomen flattened, moderately sclerotized, tergites 1–7 subequal in length and width; 8th tergite approximately 2X length of 7th. Sternite 8 emarginate apically. Tergite 9 (Fig. 5) hinged, capable of considerable dorso-longitudinal movement, extending ventrally, thus forming the urogomphal plate (Figs. 5–6), widest basally where it forms well developed, subtruncate to slightly, obtusely rounded lateral lobes; surface of urogomphal plate bearing numerous, well-developed callosities and several larger, dorsal and lateral setigerous calli on the dorsal and lateral surfaces of the urogomphi; urogomphi heavily sclerotized, long, slender, subparallel, tapering and acuminate apically; ventral surface of urogomphal plate shallowly, but sharply excavate basally at articulation with 9th and 10th sternites, excavation narrowing distally to bases of urogomphi and urogomphal lip. Urogomphal plate possessing a strongly reduced but heavily sclerotized urogomphal lip ventrally, between the two, heavily sclerotized, relatively shallow urogomphal pits (Fig. 6), which, in turn, arise distally between the heavily sclerotized, fixed urogomphi, and bear characteristic, parallel rugulae (Figs. 6–7). Sternite 9 (Fig. 6) broadly, transversely U-shaped, divided mesally by weak, desclerotized line, partially recessed into shallow emargination of 8th sternite, possessing continuous semicircular arch of approximately 26–30 well-developed asperites along anterior margin. Tenth segment reduced, transversely ovate, basal margin rounded, recessed into emarginations of 9th sternite, visible ventrally.

Spiracles: One pair of well-developed, ovate thoracic spiracles, situated ventro-laterally on laterotergite along anterior end of mesothorax. Paired, ovate abdominal spiracles, subequal in size, located on dorsolateral margin of 1st abdominal tergite and ventrolateral margins of abdominal laterotergites 2–7; paired spiracles of abdominal laterotergite 8 (Fig. 6) slightly larger, annular-ovate, located ventrolaterally at distal 1/4 of its length.

Material examined. [1 adult ♀ with exuvium]: TAIWAN: Heping District, // Taichung City, Tahsuehshan, // Dasyueshan trail 18.8k, // 24.250448°N / 120.917915°E; // elevation 1240m (larva A) // 25 November 2012 // W.-R. Liang; [2nd label]: larva collected beneath bark of // decaying hardwood log; // 21.I.2013, pupated // 28.I.2013, eclosed; [3rd label]: Pseudopyrochroa // carinifrons ♀ // Kôno // det. D. K. Young. [1 adult ♂ with exuvium]: TAIWAN: Heping District, // Taichung City, Tahsuehshan, // Dasyueshan trail 18.8k, // 24.250448°N / 120.917915°E; // elevation 1240m (larva B) // 25 November 2012 // W.-R. Liang; [2nd label]: larva collected beneath bark of // decaying hardwood log; // 22.I.2013, pupated // 29.I.2013, eclosed; [3rd label]: Pseudopyrochroa // carinifrons ♂ // Kôno // det. D. K. Young. [1 adult ♀ with exuvium]: TAIWAN: Heping District, // Taichung City, Tahsuehshan, // Dasyueshan trail 18.8k, // 24.250448°N / 120.917915°E; // elevation 1240m (larva C) // 25 November 2012 // W.-R. Liang; [2nd label]: larva collected beneath bark of // decaying hardwood log; // 24.I.2013, pupated // 31.I.2013, eclosed; [3rd label]: Pseudopyrochroa // carinifrons ♀ // Kôno // det. D. K. Young]. [3 adult ♂♂]: TAIWAN: Heping District // Malunshan; ca. 1067m // Taichung City, / 24.191681°N / 121.019503°E // 13 February 2013 // Yun Hsiao, leg.; [2nd label]: Reared from larva ex: // beneath bark and in moist, // rotting wood of dead // broad-leaf tree; [3rd label]: Pseudopyrochroa // carinifrons ♂ // Kôno // det. D. K. Young. [2 exuviae]: TAIWAN: // Heping District // Malunshan; ca. 1067m // Taichung City, // 24.191681°N / 121.019503°E // 13 February 2013 // Yun Hsiao, leg. // collected from beneath bark // and in moist, rotting wood of // dead broad-leaf tree // ASSOCIATED ADULT IN // PINNED COLLECTION; [2nd label]: Pseudopyrochroa // carinifrons ♂ // Kôno // det. D. K. Young. [1 exuvium]: TAIWAN: // Heping District // Malunshan; ca. 1067m // Taichung City, // 24.191681°N / 121.019503°E // 05 February 2013 // Yun Hsiao, leg. // collected from beneath bark // and in moist, rotting wood of // dead broad-leaf tree // ASSOCIATED REARED // ADULT MALE NOT // COLLECTED (ESCAPED); [2nd label]: Pseudopyrochroa // carinifrons ♂ // Kôno // det. D. K. Young. [1 complete larva]: TAIWAN: // Heping District // Malunshan; ca. 1067m // Taichung City, // 24.191681°N / 121.019503°E // 13 February 2013 // Yun Hsiao, leg. // collected from beneath bark // and in moist, rotting wood of // dead broad-leaf tree; [2nd label]: Pseudopyrochroa // carinifrons // Kôno // det. D. K. Young. [1 partial larva (most of abdomen, including urogomphi)]: TAIWAN: // Heping District // Malunshan; ca. 1067m // Taichung City, // 13 February 2013 // Yun Hsiao, leg. // collected from beneath bark // and in moist, rotting wood of // dead broad-leaf tree; [2nd label]: Pseudopyrochroa // carinifrons // Kôno // det. D. K. Young.

Diagnosis. The structure of the apico-adoral surface of the maxillae ( Figs. 2–4 ) has been shown to be somewhat diagnostic at the species level in larvae of Pseudopyrochroa ( Hayashi 1969, Young 1996b, 2001).

Most diagnostic, however, are structures associated with the ninth abdominal segment. The structure of the urogomphal plate has consistently been very useful and reliable for species recognition of a wide range of pyrochroid larvae (e.g., Hayashi 1969, Young 1975, 1991, 1996b, Pollock 1995). The most diagnostically useful characters of P. carinifrons larvae are the elongate, slender, subparallel urogomphi (Figs. 5–6), the strongly reduced but heavily sclerotized urogomphal lip, and shallow urogomphal pits with characteristic fingerprint-like parallel rugulae (Figs. 6–7).

The urogomphal plate anatomy of the Japanese Pseudopyrochroa atripennis (Lewis) ( Hayashi 1969: Figs. 12, 21) is somewhat similar to that of P. carinifrons but the basal lateral lobes of P. atripennis are more acutely produced, apically. Larvae of the Indonesian Pseudopyrochroa longa (Perty) also possess a similar form of the urogomphal plate ( Figs. 12–13). In P. longa , however, the asperites of the 9th sternite are smaller and far more numerous ( Fig. 13) and the urogomphal lip and pits are more complexly developed ( Figs. 12–13).

Figures

FIGURES 1 – 4. Pseudopyrochroa carinifrons Kôno, larva: Fig. 1: habitus, dorsal view; Fig. 2: cranium, ventral view; Fig. 3: mouthparts: mandibles, hypopharyngeal sclerome, dorsal view; Fig. 4: mouthparts: maxilla, labium, ventral view.