Rentonium Crowson, 1966

Kolibac, Jiri, 2013, Trogossitidae: A review of the beetle family, with a catalogue and keys, ZooKeys 366, pp. 1-194 : 98

Genus Rentonium Crowson, 1966 Figs 9 , 17 ; Map 10

Rentonium Crowson, R. A. 1966: 121.

Type species.

Rentonium daldiniae Crowson, 1966 [by original designation and monotypy]

Crowson, R. A. 1970: 6. Kolibáč, J. 2005: 81 (redescription). Kolibáč, J. 2006: 111 (phylogeny)

Description.

Body size: 1.3-1.5 mm. Body shape conglobate. Gular sutures wide, subparallel. Frontoclypeal suture absent. Frons: longitudinal groove or depression absent. Cranium ventrally: tufts of long setae at sides absent. Submentum: ctenidium absent. Antennal groove present. Eyes: size large, lateral. Eyes number: two. Epicranial acumination absent. Mandibular apical teeth number: one. Mola reduced but present. Penicillus (at base) absent. Pubescence above mola or cutting edge absent. Ventral furrow absent. Basal notch shallow or absent. Labrum-Cranium not fused. Epipharyngial sclerite absent. Lateral tormal process: projection projection not developed (all remaining). Ligula: ciliate setae absent. Ligula rigid, not retroflexed, weakly emarginate. Hypopharyngeal sclerite H-shaped. Antenna 10-segmented. Antennal club symmetrical, sensorial fields absent. Front coxal cavities externally open, internally closed. Pronotum transverse. Epipleuron thin. Elytral interlocking mechanism absent, carinae reduced. Elytral punctation irregular, scales absent. Wing: radial cell oblong (or reduced), wedge cell absent, cross vein MP3-4 absent, cross vein AA1+2-3+4 absent. Front tibiae: spines along side moderate. Hooked spur absent, apical spurs not hooked or weakly hooked. Claws: denticle absent. Spiculum gastrale present. Tegmen composed of only a single unit.

Larva: Frontal arms V-shaped. Epicranial stem absent. Endocarina present. Hypostomal rods absent. Stemmata number: five. Mandibular apical teeth number: two, horizontally situated. Lacinia mandibulae with several small spines. Mola absent. Maxillary palpi 2-segmented. Labial palpi 1-segmented. Torma: two separate lateral sclerites. Antennal joints 1, 2 transverse. Sensory appendix larger than half of joint 3. Thoracic sclerites pattern (dorsally) 1-2-2. Abdominal segment IX not divided. Tergite IX flat. Urogomphi present, hooked; median process absent.

Biology.

The single known larva described (Crowson speculated that it might be identified as Rentonium daldiniae ) was extracted from a forest litter sample (mainly Nothofagus ) at an elevation of about 500m ( Crowson 1966). An adult Rentonium daldiniae was found in Daldinia sp. fungus growing on a dead tree ( Crowson 1966). Rentonium chilense was collected in Nothofagus forest at around sea level.

Distribution.

New Zealand: Canterbury, Waimate. South Chile: Isla Bertrand.

Species:

Rentonium chilense Crowson, 1970; Chile (RAC)

Crowson, R. A. 1970: 7. Kolibáč, J. 2005: 81 (redescription)

Rentonium daldiniae Crowson, 1966; New Zealand (RAC)

Crowson, R. A. 1966: 121, 123 (supposed larva). Crowson, R. A. 1970: 7. Kolibáč, J. 2005: 81 (redescription). Kolibáč, J. 2006: 109

Figures

Figure 9. A Peltis (syn. Zimioma, Ostoma) grossa B Peltis (syn. Ostoma) ferruginea C Colydiopeltis loebli D Colydiopeltis compactum E Colydiopeltis burckhardti F Parapeltis australicum G Protopeltis viridescens H cf. Globorentonium plaumanni, Brazil (1 - 3: three different specimens from the same locality).

Map 10. A distribution of the tribe Thymalini including Rentonium - group.

Figure 17. A-B " Rentonellum " loebli (A ventral surface B prosternal intercoxal process) C cf. Globorentonium plaumanni, Brazil (C ventral surface D pro- and mesothorax ventrally E head ventrally F detail of mouthparts G protibia with tarsus H mesotibia with tarsus).