Research Article |
Corresponding author: T. Keith Philips ( keith.philips@wku.edu ) Academic editor: Michael Ivie
© 2020 T. Keith Philips, Kyle A. Whorrall, Olivia M. Gearner, Jean-Bernard Huchet.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Philips TK, Whorrall KA, Gearner OM, Huchet J-B (2020) A new genus of spider beetle (Coleoptera, Ptinidae) from western Peru. ZooKeys 934: 81-91. https://doi.org/10.3897/zookeys.934.38670
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A new genus of flightless spider beetle from Peru with two new species is described. It is characterized by unique heart-shaped fused elytra and a broad pronotum with five basal depressions. The characters of this new genus and species are illustrated and discussed and the possible phylogenetic placement of this taxon is also included.
Atacama Desert, Bostrichoidea, diversity
The spider beetle fauna of South America currently includes ca. 100 described species placed in 11 genera. Little recent work has been done on the group with the exception of publications by Bellés on Ptinus Linnaeus (1984, 1986), Bellesus Özdikmen (as Arachnomimus Bellés 1985 and see
The two new species that make up this new genus are known only from Peru. Surprisingly one of the new species discovered was in material from the Ditsong Museum located in Pretoria, South Africa. The second species was collected by one of the authors (JBH) during archaeoentomological investigations on the emblematic site of Huaca de la Luna in 2009. Documenting this genus and concomitant new species increases the known morphological range within spider beetles and will make the name available for unpublished phylogenetic studies.
Cordielytrum peruvianum Whorrall & Philips.
This genus can be recognized by the heart-shaped pair of fused elytra and the dense appressed setal scale covering (Figs
Body : small, length approximately 2 to 2.5 mm, ovoid, convex but slightly flattened dorso-ventrally, dorsally body surface completely obscured with appressed or recumbent setae, scale-like especially on head and elytra.
Head
(Fig.
Pronotum
(Fig.
Elytra
(Fig.
Thorax
(Fig.
Abdominal ventrites
(Fig.
Legs
(Fig.
Male genitalia
(Fig.
The generic name is derived from cordi = Latin for heart and elytrum = Greek for sheath in reference to the fused elytra that figuratively resemble an ideographic image of a heart.
Sexual dimorphism externally is not apparent.
Members of this genus appear to be denizens of xeric coastal areas in Peru (Fig.
Currently no information on the ecology is known with the exception of the northernmost species that was collected via traps baited with a local corn beer known as chicha: this fluid may have been attractive as a food and/or moisture source. Based on recent collections and current rearing experiments (Philips and Whorrall, unpublished), larvae feed on cat dung and likely any other type in their vicinity, such as that from other mammals, birds, or lizards.
Holotype. Peru: Ica, coastal dunes, Seely, 15.I.1980. Deposited in the Museo de Historia Natural, Lima Peru. Paratypes (6): Same data as holotype. Paratypes have been deposited in the Ditsong Museum and the collections of the authors (TKPC, JBHC, KAWC).
This species is distinguished from its congener by its more rotund shape and the narrow light tan scales covering the elytra. It is known only from the type locality in the Ica Region of Southern Peru.
Body small, compact, subovate, convex; head, pronotum, and elytra tan colored. Length (anterior of pronotum to apex of elytra) 2.16 – 2.76 (μ = 2.55 ± 0.20) mm (N = 7).
Head : densely covered in light tan, depressed, ovoid scales completely covering surface, less dense laterally, with pronounced superantennal carinae; antennomeres 1–9 densely squamous, ultimate and penultimate antennomeres with simple setae, not obscuring surface, antennomeres 1–3 and 11 slightly longer than wide, others subequal.
Pronotum : setose with scales anteriorly and longer densely matted setae posteriorly; short, erect setae sparsely placed throughout, longer at posterio-lateral edge, arising from cavities formed within matted setae, cavities distinctly larger laterally; medial cavity deep, when viewed from above, extending nearly half total length but border absent at middle, extending as a shallow groove anteriorly; two posterio-lateral cavities on each side, deep and distinct.
Elytra : surface densely covered by narrow scales, giving a finely rugose appearance; lateral edge at anterior ¼ with row of sparsely placed bristly very long setae; four prominent longitudinal carinae extending length of each elytron, including one at suture; indistinct very shallow depressions in ~ two rows between carinae; background cuticle color light reddish brown.
Ventral surface : Pro- and mesoventrites with matted setation similar to pronotum; metaventrite and abdominal ventrites with scales similar to elytra. Femora increasing in width from base to apex, girth reaching maximum around midpoint; tibiae increasing in width from base to apex, girth increasing throughout basal third then remaining equal thereafter; tarsomere 1 ca. twice as long as 2–4, ⅓ longer than 5, 2–4 sub-equal in length.
The specific name peruvianum refers to the country in South America where this species was discovered.
This species is from the Ica Region, Peru (Fig.
Holotype. Peru: Trujillo, Huaca de la Luna, Plateforme Uhle, J. B. Huchet lgt.; Piège à “Chicha, (bière de maïs), (J6)13/05/2009). Holotype deposited in the Muséum national d’Histoire naturelle, Paris, France. Paratypes (18), same data as the holotype (13); Peru- Trujillo, Huaca de la Luna, 6. V–1.VII. 2009, J.B Huchet / A. Chauchat (5). Paratypes have been deposited in the Muséum national d’Histoire naturelle, Museo de Historia Natural, Lima, and the collections of the authors (TKPC, JBHC, KAWC).
This species is distinguished from C. peruvianum by its slightly more elongate shape, the vestiture of broad, ovate tan and dark brown scales on its elytra. Currently this species is only known from the type locality in Northern Peru.
Body small, compact, subovate, convex; head and pronotum tan, elytra mottled tan and dark brown. Length (anterior of pronotum to posterior of elytra) 1.84– 2.44 (μ = 2.13 ± 0.22) mm (N = 15).
Head densely covered in light tan, depressed, ovoid scales completely covering surface, less dense laterally, with subtle superantennal carina; antennomeres 1–9 densely squamous, ultimate and penultimate antennomeres with simple setae; antennomeres 1–3 and 11 ca. twice as long as wide, others subequal.
Pronotum setose with scales anteriorly and longer densely matted setae posteriorly; short, erect setae sparsely placed throughout, longer at posterio-lateral edge, arising from cavities formed within matted setae, cavities distinctly larger laterally; medial cavity with poorly defined border, moderate in depth, when viewed from above, extending nearly one third of total length; two posterio-lateral cavities on each side, somewhat more distinct than medial cavity.
Elytra surface densely covered by broad, ovate scales, giving a coarsely rugose appearance; lateral edge at anterior ⅓ of each elytron with row of long densely placed bristly very long setae; four low longitudinal carinae extending length of each elytron, including one at suture; deep depressions in ~2 rows between carinae; background cuticle color dark reddish brown.
Ventral surface : Pro-, meso-, and metaventrites and abdominal ventrites with scales similar to elytra. Femora increasing in width from base to apex, girth reaching maximum around midpoint; tibiae increasing in width from base to apex, girth increasing throughout basal third then remaining equal thereafter; tarsomere 1 ca. twice as long as 2–4, ⅓ longer than 5, 2–4 sub-equal in length.
Etymology. The name derives from the attractive variegated pattern of dark and light-colored setae on the elytral surface.
Remarks. Many well-preserved, partial remains of this new species were initially recovered within organic material from pre-Columbian Mochica graves at the emblematic archaeological site of Huacas de Moche, located along the pacific coastal desert, in the vicinity of Trujillo, 550 km north of Lima, Peru. This archaeological complex includes two monumental pyramids built as a series of platforms: Huaca del Sol (Temple of the Sun) and Huaca de la Luna (Temple of the Moon), separated by a vast urban centre (Chauchat et al. 2009) (Fig.
The most plausible sister lineage is the genus Trigonogenius, as both are somewhat comparable morphologically and are found in the same region of South America. To support this hypothesis, an attempt to acquire a sample of DNA from a dried specimen was done but amplification attempts failed. Hence more complete data to support relationships and to truly understand where the ancestry of this taxon lies will have to wait until fresh material is processed and sequenced.
Further collecting efforts in coastal Peru south of Lima has resulted in the discovery of additional undescribed species of this genus. How many more species remain to be found in this poorly surveyed part of South America remains unknown.
We are very grateful to Ruth Müller and the late Charles Bellamy for providing us the opportunity to study specimens from the Ditsong National Museum of Natural History (Pretoria, South Africa) and in particular the support from them given while the second author was on a postdoctoral fellowship at the University of Pretoria and two sabbaticals (2008 and 2015) while at Western Kentucky University (WKU). We are indebted to Dr. Claude Chauchat (“Archéologie des Amériques,” UMR 8096, Centre National de la Recherche Scientifique), director of the French archeological mission at Huaca de la Luna for permitting JBH to conduct entomological investigations at this site, Dr Louis Deharveng, head of the Entomology department, Muséum national d’Histoire naturelle, Paris, France and Dr. Bruno Maureille (University of Bordeaux) for partially supporting the field research in Trujillo, Peru. We are very grateful to Belkys Gutiérrez, Prof. Segundo Vásquez, and our colleagues in the Department of Biological Sciences (Universidad Nacional de Trujillo, Perú) for field support at Huaca de la Luna and logistics while in Peru. Our sincere thanks to Azadeh Taghavian (Muséum national d’Histoire naturelle, Paris) who took pictures of the type specimen of Trigonogenius impressicolis Pic to verify excluding it from Cordielytrum. The authors gratefully acknowledge the Center for Biodiversity Studies at WKU and a NSF Biological Surveys and Inventories grant (DEB 0430132) that has helped support studies on spider beetles. Lastly, we thank the reviews from Xavier Bellés and Michael Ivie for their useful comments that improved the manuscript.