Chimaerocryptus, Gimmel & Leschen, 2022

Gimmel, Matthew L. & Leschen, Richard A. B., 2022, Revision of the genera of Picrotini (Coleoptera: Cryptophagidae: Cryptophaginae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 62 (1), pp. 61-109 : 76

Chimaerocryptus gen. nov.

( Figs 18 , 77 )

Type species. Chimaerocryptus johnsoni sp. nov., by present designation.

Diagnosis. This Chilean genus is easily distinguished by the explanate pronotum with asymmetrical crenulations along the lateral carina ( Fig. 77 ) and a carinate prosternal process. Additionally, the body is densely setose dorsally, the antennal club consists of three antennomeres, and the abdominal ventrites are free.

Description. Length 1.80–1.85 mm. Body form ( Fig. 18 ) elongate and parallel-sided, somewhat shining dorsally, with dense decumbent setae and often with a few long, sparse, suberect to erect setae dorsally; unicolorous. Head with tempora, length about 1/3 length of eye; vertex with temporal depression immediately anterior to ridge; band of reticulate sculpture absent, and glabrous. Frontoclypeus not projecting laterally; raised portion of frons between antennal insertions not constricted, wider than antennal club. Transverse ridge above antennal insertions absent. Eye large, rounded, contacting antennal cavity; interfacetal setae present. Antennal club consisting of 3 antennomeres; antenna inserted into small cavity; antennomere 9 subequal in width to antennomere 10. Mandible with apex bifid, subapical serrations present. Maxillary palpomere 4 distinctly longer than 3; palpomere 4 not subulate. Gena without antennal groove; genal spines subacute. Gular sutures incomplete, not reaching occipital foramen. Pronotum ( Fig. 77 ) explanate, not strongly constricted at base, narrower than elytra, almost parallel-sided, widest at middle; anterior angles absent, not projecting anteriorly (not extending anterior to cervical foramen of prothorax), without a distinct flat glandular surface or platform; lateral carina present and complete, smooth on right side and undulate in anterior 1/3 on left side, with well-developed and widened lateral glabrous space within a depressed submarginal impression, width of lateral bead about as wide as discal puncture and narrower than antennal funicle; disc with broad basal impression present in basal 1/3; paramedial carinae and paralateral plicae absent; posterolateral angles sharp, strongly acute. Prothoracic hypomeron fused to prosternum. Prosternum with anterior margin on lower plane than disc; prosternal process carinate with medial longitudinal keel extending length of process, lateral beads absent, slightly expanded subapically behind coxae and apically acute; procoxal cavity with anterolateral notch. Scutellar shield clearly visible, transverse and narrow. Elytron without a distinct humeral tooth; subbasal impression present, subapical impression absent; subapical gape present; punctation confused, dense and moderately impressed; vestiture dual with a few long, sparse, erect setae present laterally or on disc, decumbent setae forming undulate pattern, with postscutellar and subapical setae directed posteriorly. Hind wing well developed. Mesoventrite with mesoventrital cavity deep with distinct edges. Mesanepisternal pit present, glabrous. Metaventrite without postcoxal lines; discrimen less than 1/2 length of metaventrite, posterior notch of metaventrite present. Metendosternite with anterior tendons approximate. Tarsi 5-5- 5 in female, 5-5- 4 in male; tarsi slender, tarsomere 5 as wide as preceding tarsomeres in lateral view; pro- and mesotarsomere 4 with few ventral setae; mesotarsomere 3 weakly lobed, with few setae; mesotarsomeres 2–4 of subequal lengths, mesotarsomere 1 longer than 2, mesotarsomere 5 about as long as mesotarsomeres 1–3 combined. Abdominal ventrites free and with medial and lateral calli absent, intersegmental crenulations absent; ventrite 1 with intercoxal process broadly rounded, without postcoxal lines; medio-basal thickenings of ventrites 3–5 absent; apex of ventrite 5 without crenulations.Aedeagus with tegminal strut absent, tegminal arms fused; parameres separate and articulated to phallobase, inner surface not concave, length about 3× longer than wide; apices unisetose; attachment point to phallobase not constricted, interparameral process absent; basipenis 6× longer than distipenis, with median carina; distipenis relatively short, outer rims smooth, lateral lobes poorly developed and widely separated, symmetrical; internal sac with one elongate endophallite that is not bifurcate anteriorly.

Remarks. This monotypic genus is known by two specimens of a single species, a male and a female. In both specimens, the bizarrely asymmetrical pronotum has the same conformation, leading us to conclude that the condition is not teratological.

Etymology. The generic name is derived from a combination of the Greek “ Chimaera ”, a hybrid monster, in reference to the asymmetrical pronotum of the type species, and “ -cryptus ”, a common generic ending in Cryptophagidae . The gender is masculine.

Biology. The single species has been collected in a FIT set in Nothophagus / Araucaria forest.

Distribution. Chile.

Included species (1). Chimaerocryptus johnsoni sp. nov.

Figures

Figs 10–18. Habitus of species of Picrotini. 10 – Bellascelis n. sp. 1 (Australia: Qld); 11 – Bellascelis n. sp. 2 (Australia: NSW); 12 – Chileothortus infuscatus sp. nov.; 13 – Chiliotis sp. 1; 14 – Chiliotis sp. 2; 15 – Chiliotis sp. 3; 16 – Chiliotis sp. 4; 17 – Chiliotis sp. 5; 18 – Chimaerocryptus johnsoni sp. nov. Scale bars = 1 mm.

Figs 77–81. Characters of Picrotini. 77–78 – detail of pronotum. 77 – Chimaerocryptus johnsoni sp. nov.; 78 – Odonotosomatula carltoni sp. nov. 79 – pronotum and base of elytra, Humerocryptus n. sp. 1. 80 – antennal club, Paragnetaria slipinskii sp. nov. 81 – eye, Cryptothelypterus pteropilosus Leschen & Lawrence, 1991. Abbreviations: pp = paralateral plica.