Acalanthis Erichson, 1844

Kolibac, Jiri, 2013, Trogossitidae: A review of the beetle family, with a catalogue and keys, ZooKeys 366, pp. 1-194 : 15-16

Genus Acalanthis Erichson, 1844 Figs 1 , 3 , 13 ; Map 3

Acalanthis Erichson, W. F. 1844: 446.

Type species.

Acalanthis quadrisignata Erichson, 1844 [by monotypy]

Léveillé, A. 1910: 4. Arias, E. et al. 2009: 39. Crowson, R. A. 1964a: 299 (larva, described as Phanodesta ). Crowson, R. A. 1970: 13. Kolibáč, J. 2005: 40. Kolibáč, J. 2006: 106 (larva; see Crowson 1964a)

Remarks.

An antennal apex I figured ( Kolibáč 2005: 89, Pl. 1-Fig. 5) was associated with Acalanthis quadrisignata in error, as correctly noted by Arias et al. (2009). The drawing probably belongs to Calanthosoma flavomaculata .

Description.

Body size: 6.0-9.0 mm. Body shape elongate. Gular sutures narrow, subparallel at apex. Frontoclypeal suture absent. Frons: longitudinal groove or depression absent. Cranium ventrally: tufts of long setae at sides present. Submentum: ctenidium absent. Antennal groove present. Eyes: size moderate Eyes number: two. Epicranial acumination moderate. Lacinial hooks: two. Galea: shape sub-clavate. Galea: ciliate setae absent. Mediostipes-Lacinia partially fused. Palpifer: outer edge even. Mandibular apical teeth number: two, horizontally situated. Mola reduced but present. Penicillus (at base) present (fine, often membranous). Pubescence above mola or cutting edge present. Ventral furrow present. Basal notch moderate. Labrum-Cranium not fused. Epipharyngial sclerite present. Lateral tormal process: projection curved downwards, processes not connected ( Airora ). Ligula: ciliate setae absent. Ligula rigid, weakly retroflex, deeply emarginate. Hypopharyngeal sclerite H-shaped. Antenna 10-segmented, Antennal club asymmetrical, sensorial fields present. Front coxal cavities externally closed, internally open. Pronotum cordate. Prepectus absent. Middle coxal cavities closed. Elytra: long hairs present. Epipleuron moderate. Elytral interlocking mechanism present, carinae reduced. Elytral punctation regular, scales absent. Wing: radial cell triangular, wedge cell present, cross vein MP3-4 present, cross vein AA1+2-3+4 absent. Front tibiae: spines along side moderate. Hooked spur present. Claws: denticle absent. Parasternites number along ventrites III-VII: one. Spiculum gastrale absent. Tegmen composed of three parts. Coxitae undivided.

Larva: Frontal arms V-shaped. Epicranial stem reduced. Endocarina present. Antennal joints 1 and 2 elongate. Thoracic sclerites pattern (dorsally) 1-2-2. Tergite IX depressed. Urogomphi present, hooked; median process absent.

Biology.

Predatory. Crowson (1964a) remarked " numerous insect fragments in gut " of an assumed Phanodesta larva but, as he noted later ( 1970: 1), the larva probably belongs to some species of Acalanthis . Its brief description in his key ( 1964a: 299) in fact agrees perfectly with the larval characters of Egoliini . The adult gut contents of Acalanthis quadrisignata included insect fragments ( Crowson 1964a). Elizabeth Arias and colleagues ( Arias et al. 2009) caught numerous Acalanthis specimens by canopy fogging and beating vegetation in forests, yielding a range of species including some Nothophagus , Araucaria , Schinus , and Rhaphitamnus .

Distribution.

Temperate forests of central Chile and Argentina ( Arias et al. 2009).

Species:

Acalanthis mirabilis Reitter, 1876; Chile (AL, varA)

Léveillé, A. 1910: 4. Arias, E. et al. 2009: 40

Acalanthis quadrisignata Erichson, 1844; Chile (AL, varA)

Léveillé, A. 1910: 4. Arias, E. et al. 2009: 39. Kolibáč, J. 1999b: 12. Kolibáč, J. 2005: 40 (redescription)

Acalanthis semimetallica Fairmaire, 1861 ( Clerus ); Chile (AL, varA)

Léveillé, A. 1910: 4. Arias, E. et al. 2009: 41

Figures

Figure 1. Adult morphology: A Alindria sp. from Laos, ventral surface B Leipaspis lauricola, labium C Airora cylindrica, antennal club D Corticotomus cylindricus, mandible dorsally E Airora cylindrica, mandible ventrally F Acalanthis quadrisignata, labium G Acalanthis quadrisignata, maxilla H Acalanthis quadrisignata, wing I Peltonyxa deyrollei, tegmen composed of 3 parts J Airora cylindrica, tegmen composed of 2 parts.

Figure 3. A Calitys scabra B Larinotus umblicatus C Acalanthis quadrisignata D Calanthosoma flavomaculata E Calanthosoma (syn. Marnia) sipolisi F Egolia variegata G Necrobiopsis tasmanicus.

Map 3. A distribution of the tribe Egoliini.

Figure 13. A-B Calitys scabra (A head and pronotum B elytral apex with interlocking mechanism) C-D Acalanthis quadrisignata (C apex of protibia with hooked spur and lateral spines D sculpture of frons with punctures conjoined into wrinkles) E-H Gymnocheilis sp., Cameroon (E head F protibia G elytral apex H detail of scales).