Peltonotus mushiyaus Jameson and Wada, 2009

Jameson, Mary Liz & Wada, Kaoru, 2009, Five new species of Peltonotus Burmeister (Scarabaeidae: Dynastinae: Cyclocephalini) from Southeast Asia, Insecta Mundi 2009 (102), pp. 1-16 : 11-12

Peltonotus mushiyaus Jameson and Wada , n. sp.

( Fig. 6 , 12 , 21 , 26 )

Type Material. Holotype female loaned from FUJI and housed at NSMT with following label data and maxilla mounted beneath specimen: a) “Sipitang Perf., Sabah N. BORNEO, E. MALAYSIA, APR. 2002.” (typeface) and b) our holotype label. Specimen lacking female genitalia.

Description. Holotype female ( Fig. 6 ). Length 11.8 mm. Widest width 6.3 mm. Color ( Fig. 6 ): Head, scutellum, pronotal margins, elytral margins, propygidium, pygidium, and venter castaneous; disc of pronotum orangish-tan; disc of elytra orangish-tan with broad, castaneous maculae. Dorsal surface of elytra with iridescent bloom. Head: Surface of frons with base moderately densely punctate, disc and apex densely punctate, some confluent at margins; punctures simple, some unisetigerous; setae short, tawny. Surface of clypeus moderately densely punctate, some confluent at apex and margins; punctures simple, some unisetigerous; setae short. Clypeus laterally weakly bowed, apex truncate, corners square, beaded; bead weakly arcuate posteriorly. Labrum broadly emarginate at middle. Mandible with external edge rounded, inner apex with 1 tooth. Mentum with apical half rounded, notched at middle; palpomere 2 not dorsoventrally flattened, about 1.5 times width of palpomere 1, lacking abundant setae. Maxilla ( Fig. 12 ): mala lacking lamellate setal brush; stipes with sparse, moderately long, simple setae (not flattened or curly at apex); palpomere 2 without internomedial bump. Antennal club slightly longer than segments 2- 7. Pronotum: Posterior bead lacking; anterior bead complete. Surface moderately densely punctate; punctures simple, lacking setae. Lateral margin lacking long setae. Elytron: Sutural length about 4.3 times length of scutellum. Surface with 5 weakly developed, punctate, longitudinal striae between suture and humerus; punctures ocellate or elongate, moderate in size, moderately dense, lacking setae. Intervals similarly sculptured. Epipleuron ( Fig. 21 ) in ventral view not expanded, not incised at apex; in dorsal view expansion not developed adjacent to metacoxa. Propygidium: Surface shagreened and moderately densely punctate, punctures small (base) to moderately large (apex), simple, lacking setae. Pygidium: Surface moderately densely punctate (disc) to densely punctate (margins); punctures ocellate, lacking setae. Venter: Prosternal keel broadly triangular; apex projecting anteriorly at about 90 o with respect to ventral plane, extends to about 1/3 height of protrochanter, rounded at apex. Legs: Protibia tridentate, teeth subequal; lateral margin with short, dense setae. Claws (all legs) subequal in size, 1/2 length of tarsomere 5, weakly angled toward venter.

Diagnosis. The orangish-tan pronotal and elytral coloration ( Fig. 6 ) of this species separates it from all known species of Peltonotus . In addition, the poorly developed prosternal keel is unique to this species (weakly developed and produced to only about 1/3 height of protrochanter). We hypothesize that males of this species will possess orangish-tan elytra with castaneous vittae or maculae, similar to the sexual dimorphism in elytral coloration observed in P. vittatus Arrow.

Etymology. The specific epithet, “ mushiyaus ” is derived from the Japanese words “mushi” (insect) and “ya” (man). In Japanese, “mushi ya” is used to describe those people who are very important to the study of beetles and insects. We name this species in honor of Mr. Masayuki Fujioka who has helped to foster greater knowledge of scarab beetles in Japan and world-wide. For scarab enthusiasts, Mr. Fujioka is “mushi ya”. The beautiful specimen on which the species is named was lent to us from Mr. Fujioka.

Distribution ( Fig. 26 ). Sabah State, Bornean Malaysia.

Locality records (1 specimen) from FUJI and deposited at NSMT. BORNEAN MALAYSIA (1). Sabah State (1): Sipitang Perf.

Temporal Data. April (1).

Remarks. Peltonotus mushiyaus is the smallest species in the genus Peltonotus (the next smallest species is P. rubripennis which ranges in size from 12.0- 12.5mm). This is the only known species of Peltonotus in which the female possesses orangish-tan elytra with dark maculae ( Fig. 6 ).

Females of three species of Peltonotus share the simple form of the epipleuron ( Fig. 21 ): P. fujiokai Jameson and Wada , P. nethis Jameson and Wada , and P. rubripennis . Peltonotus mushiyaus is separated from P. fujiokai based on the complete anterior pronotal bead (incomplete at middle in P. fujiokai ). It is separated from P. nethis based on broadly emarginate apex of the labrum (deeply, narrowly emarginate in P. nethis ) and the lack of a dense lamellate setal brush on the maxilla (present in P. nethis ). It is separated from P. rubripennis based on the epipleural expansion which is not developed in dorsal view (moderately developed adjacent to metacoxa in P. rubripennis ) and weakly developed prosternal keel that extends to about 1/3 height of protrochanter (in P. rubripennis , the keel is elongate and produced to about 1/2 height of protrochanter). Females of two previously described species of Peltonotus are not known: P. deltomentum Jameson and Wada and P. karubei . We ruled out the possibility that this species could be either of these species: females of P. deltomentum will possess a broadly triangular apex of the mentum (broadly rounded in P. mushiyaus ), and females of P. karubei will possess a labrum that is deeply, narrowly emarginate at the apex (broadly emarginate in P. mushiyaus ). Females described herein ( P. favonius and P. animus ) do not possess the characters observed in P. mushiyaus .

In the female key to species by Jameson and Wada (2004), specimens of P. mushiyaus will key to P. vittatus . However, characters that are observed in P. vittatus (e.g., well-defined incision on the epipleuron, elytral coloration reddish) clearly indicate that these are two distinct species.

Figures

Figure 1-7. Peltonotus species dorsal habitus. 1) P. animus (holotype, male). 2) P. cybele (holotype, female). 3) P. favonius (holotype male). 4) P. karubei (male paratype). 5) P. karubei (male) showing variation. 6) P. mushiyaus (holotype female). 7) P. tigerus (holotype female). Scale bar = 2 mm.

Figure 8-13. Maxilla (dorsal view) showing mala with or without lamellate setal brush (black arrow) and form. 8) P. animus (holotype). 9) P. cybele (holotype). 10) P. favonius (holotype). 11) P. karubei. 12) P. mushiyaus (holotype). 13) P. tigerus (holotype).

Figure 19-22. Female elytral epipleuron (gray, ventral view) with position of metacoxa. 19) P. cybele (holotype). 20) P. malayensis. 21) P. mushiyaus (holotype). 22) P. tigerus (holotype) shared with P. nethis (image identical to Fig. 58 in Jameson and Wada 2004). Epipleura all the same scale. Detail of right foreleg. 23) P. favonius (holotype male). 24) P. animus (holotype male).

Figure 26-27. Distribution of some Peltonotus species in Borneo.