Chileothortus, 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 : 72-73

Chileothortus gen. nov.

( Fig. 12 )

Type species. Chileothortus infuscatus sp. nov., by present designation.

Diagnosis. This genus is quite similar to Thortus in its relatively glabrous appearance, antennae inserted within deep concavities with the frons very narrow between them, and presence of postcoxal lines on abdominal ventrite 1. Additionally, members of both genera lack pronotal platforms, and have an antennal club comprised of three antennomeres, and all abdominal ventrites are free. However, members of Chileothortus possess an undulating setal pattern on the elytra and have more conical eyes. Members of Thortus are restricted to New Zealand and its outer islands, while Chileothortus occurs only in Chile. Additionally, Chileothortus is the only genus of picrotine that has a weakly carinate elevation that arises between the antennal insertions.

Description. Length 1.46 mm. Body form ( Fig. 12 ) relatively short, fusiform, with decumbent and erect to suberect setae dorsally, setae generally long, somewhat longer setae present at base of elytra and just below margins of pronotal and epipleural carinae; reddish-brown with transverse dark band on the elytra, ventral surfaces paler, mouthparts, femora and tarsi yellow. Head with small, weakly carinate medial elevation extending from between the antennal articulations to level of middle of eye; tempora present; vertex with temporal depression immediately anterior to ridge; band of reticulate sculpture absent. Frontoclypeus projecting laterally anterior to antennal insertions; raised portion of frons between antennal insertions strongly constricted, narrower than antennal club. Transverse ridge above antennal insertions present. Eye well-developed, not contacting antennal cavity; interfacetal setae absent. Antenna inserted into large cavity on head; antennal club consisting of 3 antennomeres, but almost appearing to consist of 2 antennomeres since antennomere 9 is reduced, intermediate in width between antennomeres 8 and 10. Maxillary palpomere 4 longer than 3; palpomere 4 subulate. Gena without antennal groove; genal spines acute. Gular sutures present. Pronotum not explanate, not weakly constricted at base, slightly narrower than elytra, very lightly wider at anterior third; anterior angles not projecting anteriorly (not extending anterior to cervical foramen of prothorax), without a distinct flat glandular surface or platform; lateral carina present and complete, not bearing setigerous tubercles, without glabrous space, width of lateral bead narrower than discal puncture and significantly narrower than antennal funicle; disc with a distinct and relatively deep transverse basal impression, about half width of pronotum; paramedial carinae and paralateral plicae absent; posterolateral angles nearly right and distinct. Prothoracic hypomeron fused to prosternum, suture not evident, but complete groove present, without small rounded impression at posterior end. Prosternum with anterior margin on slightly lower plane as disc; prosternal process with lateral marginal beads present, parallel-sided and surface between them forming a point apically and connected across apex, process not expanded apically, apex subacute; procoxal cavity with anterolateral notch. Scutellar shield clearly visible and transverse. Elytron lacking humeral tooth and subbasal impression; subapical gape present; punctation confused and moderately to sparsely dense; vestiture uniform but apex forming undulate pattern, with postscutellar and subapical setae directed posteriorly. Hind wing vestigial. Mesoventrite with mesoventrital cavity deep and flanked by sharp carinae. Mesanepisternal pit absent. Metaventrite without postcoxal lines; discrimen absent, posterior notch of metaventrite present. Tarsi 5-5- 4 in male; tarsi not slender, tarsomere 5 wider than preceding tarsomeres in lateral view; pro- and mesotarsomere 4 with ventral setae; mesotarsomere 3 unlobed, with few setae; mesotarsomeres 1–4 of equal lengths, mesotarsomere 5 short, about as long as mesotarsomeres 1–3 combined. Abdominal ventrites free, intersegmental crenulations absent; ventrite 1 with intercoxal process acute, with postcoxal lines present, acuminate; medio-basal thickenings of ventrites 3–5 absent; apex of ventrite 5 without crenulations. Remarks. This monotypic genus is known by one male specimen which remains undissected; therefore, the following characters were not observed: apex of the mandible, length of gular sutures, apex of the prosternal process, form of the metendosternite, presence and distribution of abdominal calli, form of the spiracles, and form of the aedeagus. The elytral cuticle is somewhat transparent and it appears that the hind wing is vestigial and the medial ridge on the frons may be a male character.

Etymology. The generic name is in reference to Chile, the country of origin of the genus, and the genus Thortus , with which it shares many characters. The gender is masculine.

Biology. The single species has been collected by Berlese extraction in coastal rain forest.

Distribution. Chile.

Included species (1). Chileothortus infuscatus 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.