Erotylus melanophthalmus Duponchel, 1825

Pecci-Maddalena, Italo S. C., Skelley, Paul & Lopes-Andrade, Cristiano, 2021, Taxonomic review of Mycomystes Gorham, 1888 (Coleoptera: Erotylidae: Tritomini), Journal of Natural History 54 (47 - 48), pp. 3075-3102 : 3091-3093

Lectotype of Erotylus melanophthalmus Duponchel, 1825 , here designated (MRSN;

Figure 40–41 )

‘ LECTOTYPE [printed] Erotylus melanophthalmus Duponchel 1825 [handwritten] \ Mycotretus melanophthalmus ( Duponchel 1825) [handwritten] det. I. Pecci-Maddalena 2017 [printed]’.

Type specimens of synonymised species.

Lectotype of Erotylus cinctellus Guérin-Méneville, 1841 , here designated ( MNHN; Collection Maurice Sedillot; Figure 45–46 )

‘ Mycotretus cinctellus [handwritten] Coll. Thoms. [printed]\ Brésil [printed]\Type [printed]’. Lectotype of Mycotretus discoidalis Taschenberg, 1870 , here designated (ZNS; Figure 47–48 ). LECTOTYPE, Mycotretus discoidalis TASCHENBERG, 1870 , det. I. Pecci- Maddalena 2017 [printed] discoidalis, Zeitschr. 1870 . Colomb. Wallis [handwritten]”.

Other specimens examined (27)

‘ cinctellus ’ colour pattern: 1 male ( MNRJ, dissected) ‘ ColeÇão M . Alvarenga [printed] \Chapare, Bolivia IV . 1953, A. Martinez [printed]\ Mycotretus cinctellus Guerin . 1841 [handwritten]\M . Alvarenga det . [printed] 1984 [handwritten]’; 1 male ( MNRJ, dissected) ‘ ColeÇão M . Alvarenga [printed]\ Homeotipo [red label, printed]\ Museo La Plata [printed] \11-1941 [handwritten] VILLA P . MONTI BURRUYACU, PROV. TUCUMAN [printed] \ Mycotretus cinctellus Guérin, 1841 [handwritten], M . Alvarenga det . [printed] 1971 [handwritten]\ Mycolybas cinctellus Guér-Comp. Col. Bruch [handwritten]\2018 [printed]\PMFD [?] [handwritten]’; 1 (FSCA) ‘ Buen Amigo, San Luis Monteverde, A.C., Arenal , Prov . Punta , COSTA RICA, 1000–1350 m . May 1994, Z. Fuentes, L N, 2540850_449250 #2926\[barcode label] COSTA RICA INBIO CRI001 894391’; 1 male, 1 female, 2 gender not determined ( FSCA, dissected) ‘Panama: Darién, Cana Biological Station , 530 m, 7°45 ʹ 18’NM, 77°41 ʹ 6”W, 9 June 1996; J . Ashe, R. Brooks , PAN1AB96 086, ex: cluster of gilled mushrooms”, barcode labels, one on each separate specimen ‘SM0047965 KUNHM-ENT’ ‘SM0047972 KUNHM- ENT’, ‘SM0047980 KUNHM-ENT’, ‘SM0047986 KUNHM-ENT’; 1 ( FSCA) ‘ PERU: Tambopata Prov ., 15 km NE Pto . Maldonado , 20 June 1989, 200 m, J .Ashe, R. Leschen, #185, ex: white Agaricales’ ; 1 ( CMNO) ‘ BOLIVIA, Sta . Cruz, Potrerillos de Guenda , 17.40.49S – 63.27 .36 W, 4–7 IV. 1998 /H. & A. Howden’ ; 1 ( FSCA) ‘ BOLIVIA: Dpt . La Paz, Prov . Sud Yungas, Puente Villa , 4300 ʹ, 19–24-V-1989, J . E. Eger , coll .’; 1 ( FSCA) ‘ BOLIVIA: Dept . Santa Cruz, Prov . Ichilo, “Cafetal”, 5.VIII.1990 ’\‘FMHD#90-139, forest, on gilled mushroom, P.Parrillo, No.005, FIELD MUSEUM’; 1 ( FSCA) ‘ BOLIVIA: Santa Cruz, Dpt. 4 km N. Bermejo, 7 February 2012, J. Wappes & A. Bonaso’ \‘Refugio los Volcanes, El 1045–1350 m, 18°06’S, 63°36’W ” . ‘ melanophthalmus ’ colour pattern: 1 female ( MCNZ, dissected) ‘ Derrubadas , RS, Parque Est . do Turvo, 12–17 .I .2002, R . Ott col . [printed]\Col. MCN. [printed] 218001 [handwritten]’; 1 female ( MCNZ, dissected) ‘ Tapes, RS ( Faz. São Miguel ), 17 .XII .2003, Equipe Probio col. [printed]\Col. MCN 225664 [printed]’; 1 male ( MCNZ, dissected) ‘ Tapes, RS ( Faz. São Miguel ), 17 .XII .2003, Equipe Probio col. [printed]\Col. MCN 225721 [printed]’; 1 male ( MCNZ, dissected) ‘ Triunfo , RS (COPESUL), 14–15 .I .1997, L . Moura col . [printed]\Col. MCN [printed] 215755 [handwritten]\M. melanophtalmus [handwritten]’. 1 male, 1 gender not determined ( FSCA, dissected) ‘ Fazenda Bom Jesus das Araucárias Reserve (PR, Brazil), Cultivo de Pleurotus sp ., P. L. Lopes coll. 18–19 .III .2008 (noon)’; 1 female (FSCA, dissected) ‘ VENEZUELA: Mérida, 6 km. S. Azulita , 15 July 1986, R . S. Miller collr’; 2 males, 3 females ( FCSC, dissected) ‘ ARGENTINA: Misiones, Loreto, I-2001, Coll . P . Fidalgo, Malaise trap, subtropical wet forest’ . ‘ discoidalis ’ colour pattern: 1 specimen ( FSCA) ‘ Chancha-mayo [handwritten], Peru [printed]’; 1 male ( FSCA, dissected) ‘ PERU: Dept . Junin, Pampa Hermosa Lodge 1220 m, 2-4-XI-2009, J . Heppner, C. Carrera, E. Huamani’; 1 female ( FSCA, dissected) ‘ ECUADOR: Sucumbios, Sacha Lodge, 0.5°S, 76.5°W, 270 m, 13–23-VI- 1994, Hibbs , ex: malaise’ .

Diagnosis

Body oval, TL = 5.3–5.35 mm (5.32 mm, n = 2); similar to M. ferrugineus from Mexico, but differing especially in the tibiae not forming an outer apical and pointed angle, and the distribution being from Costa Rica to Argentina; clypeus with a marginal bead fine and complete across apex; mentum plate subpentagonal, nearly circular; colour pattern, with exception of antennomeres VIII–XI and apical mandibular teeth, full yellowish to reddish-brown. Genitalia with penile flagellum sclerotised and slightly sinuous; gradually narrowed until apex and approximately 0.95× the length of penis; head of flagellum subtriangular. Vaginal process present, narrowed and elongate to the level of gonostyli.

Distribution

From Central America to Argentina ( Alvarenga 1994, confirmed here) ( Figure 55 ).

Nomenclature

Mycotretus cinctellus and M. discoidalis have almost identical black elytra with yellowbrown lateral and apical margins. They differ in the colour and shape of the scutellar shield, and medial anterior and posterior pronotal margins, which are black and narrow in M. discoidalis and yellowish-brown and comparatively broader in M. cinctellus . On the other hand, in M. melanophthalmus the scutellar shield and elytra are completely yellowish-brown. Despite these colour variations, there are no external morphological differences. Additionally, specimens with these three phenotypes (black and yellowish-brown) were dissected and their male and female terminalia have the same morphology. All these observations, together with similar body shape and congruent geographic distributions support their synonymy here.

Remarks

Unlike synonyms of M. apicalis , the series of specimens only have three colour patterns without intermediate states between them. Apart from few sparse records, these patterns appear to show a definable distribution, as follows: ‘ melanophthalmus ’ in the southeastern and southern Neotropical region; ‘ cinctellus ’ more Andean-Central America; ‘ discoidalis ’ distribution congruent with ‘ cinctellus ’ and also recorded in the westernmost portion of upper Amazon. These colour variations and their relation with genetic and environmental factors (temperature, elevation, and others) may deserve additional study.

The type-locality of M. cinctellus is Bolivia ( Guérin-Méneville 1841: 154). However, the specimen studied by us from the MNHN is labelled ‘Type’ and ‘Brésil’, which were likely added posteriorly. We believe that was an inadvertent mistake, probably a ‘B.’ in the original label erroneously interpreted as ‘Brésil’.

Figures

Figure 55. Geographical distribution of species of Mycomystes Gorham, 1888. Mycomystes apicalis (Lacordaire, 1842), Mycomystes coccineus (Lacordaire, 1842), (Diamond) Mycomystes melanophthalmus (Duponchel, 1825), Mycomystes nigriventris Pecci-Maddalena and Lopes-Andrade, 2020 and Mycomystes peruvianus (Kirsch, 1876).

Figure 40-48. Specimens of Mycomystes melanophthalmus (Duponchel, 1825): (40–41) Lectotype of Erotylus melanophthalmus Duponchel, 1825 (MRSN) and its labels. (42–43) Male from Rio Grande do Sul (South Brazil) (MCNZ). (44) Head of a specimen from the Araucárias Reserve (Paraná, Brazil (FSCA). (45–46) Lectotype of Erotylus (Brachymerus) cinctellus Guérin-Méneville,1841, new synonym (MNHN). (47–48) Lectotype of Mycotretus discoidalis Taschenberg,1870, new synonym (ZNS). Scale bars: 1 mm (40, 45); 0.5 mm (42–43).