Mycomystes apicalis ( Lacordaire, 1842 ) Pecci-Maddalena & Skelley & Lopes-Andrade, 2021

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 : 3080-3087

Mycomystes apicalis ( Lacordaire, 1842) , new combination

Figures 7–8 , 13 , 19–27 , 55

Mycotretus apicalis Lacordaire 1842: 181 [description]. Crotch 1876: 448; Gemminger and Harold 1876: 3691; Kuhnt 1909: 74; Kuhnt 1911: 48; Mader 1942: 173; Mader 1951: 214; Blackwelder 1945: 465; Alvarenga 1994: 20; Skelley 1998: 16; Moreira et al. 2010a: 573; Moreira et al. 2010b: 342; McHugh and Chaboo 2015: 278; Pecci-Maddalena and Lopes- Andrade 2017: 162; Pecci-Maddalena and Lopes-Andrade 2020: 585; Pecci-Maddalena et al. 2020: 3.

Mycotretus gemmula Lacordaire, 1842: 181 [description], new synonym. Crotch 1876: 448; Gemminger and Harold 1876: 3693; Kuhnt 1909: 73; Kuhnt 1911: 50; Mader 1942: 173; Mader 1951: 214; Blackwelder 1945: 466; Alvarenga 1994: 26; Skelley 1998: 16; McHugh and Chaboo 2015: 278.

Mycotretus gentilis Lacordaire, 1842: 182 [description], new synonym. Crotch 1876: 448 [synonymy with M. gemmula ]; Gemminger and Harold 1876: 3693; Kuhnt 1909: 73; Kuhnt 1911: 50; Blackwelder 1945: 466; Alvarenga 1994: 26.

Mycotretus nigroterminatus Lacordaire, 1842:180 [description], new synonym. Crotch 1876: 448; Gemminger and Harold 1876: 3694; Kuhnt 1909: 74; Kuhnt 1911: 51; Blackwelder 1945: 467; Guérin 1948: 20; Alvarenga 1994: 30; Skelley 1998: 16.

Mycotretus pulicarius Lacordaire, 1842: 182 [description], new synonym. Crotch 1876: 448 [synonymy with M. gemmula ]; Gemminger and Harold 1876: 3693; Mader 1942: 173; Blackwelder 1945: 466; Alvarenga 1994: 26.

Mycotretus coccinelloides Taschenberg, 1870: 198 [description], new synonym. Gemminger and Harold 1876: 3692; Kuhnt 1909: 74; Kuhnt 1911: 48; Blackwelder 1945: 466; Alvarenga 1994: 22.

Mycotretus corallipennis Crotch 1876: 448 [description], new synonym. Gemminger and Harold 1876: 3692; Kuhnt 1909: 71; Kuhnt 1911: 48; Blackwelder 1945: 466; Alvarenga 1994: 22; Skelley 1998: 16.

Lectotype of Mycotretus apicalis Lacordaire, 1842 , here designated

(MNHN; Figures 19–21 )

‘ Colombie [handwritten]\ Apicalis Lac [handwritten]\ Type [handwritten]\ Ex-Musaeo Mniszech [printed]\ LECTOTYPE [printed] Mycotretus apicalis Lacordaire 1842 [handwritten]’.

Type specimens of the synonymised species.

Mycotretus corallipennis Crotch, 1876 , lectotype, here designated (UMZC; Figure 22 ) ‘Nova Gr [green label, handwritten]\ LECTOTYPE [printed], Mycotretus corallipennis Crotch 1876 [red label, handwritten]’; Mycotretus gemmula Lacordaire, 1842 , lectotype, here designated (MNHN; Figure 23 ). ‘ Colombie [handwritten]\Gemmula Lac [handwritten] Type [handwritten]\Ex-Musaeo Mniszech [printed]\ HOLOTYPE Mycotretus gemmula Lacordaire 1842 [handwritten]’; Mycotretus gentilis Lacordaire, 1842 , lectotype, here designated (MNHN; Figure 24 ). ‘Ex-Musaeo Mniszech [printed]\ Type [handwritten]\Gentilis Lac [handwritten]\ Colombie [handwritten]\ LECTOTYPE [printed] Mycotretus gentilis Lacordaire 1842 [handwritten]’; Mycotretus nigroterminatus Lacordaire, 1842 , lectotype, here designated (MNHN; Figure 25 ). ‘Ex-Musaeo Mniszech [printed]\ Type [handwritten]\Nigroterminatus Lac [handwritten]\ Colombie [handwritten]\ LECTOTYPE [printed] Mycotretus nigroterminatus Lacordaire 1842 [handwritten]’; Mycotretus pulicarius Lacordaire, 1842 , lectotype, here designated (MNHN; Figure 26 ). ‘Ex-Musaeo Mniszech [printed]\ Type [handwritten]\Pulicarius Lac [handwritten]\ Colombie [handwritten]\ LECTOTYPE [printed] Mycotretus pulicarius Lacordaire 1842 [handwritten]’; Mycotretus coccinelloides Taschenberg, 1870 , lectotype, here designated (ZNS; Figure 27 ). LECTOTYPE, Mycotretus coccinelloides TASCHENBERG, 1870 , det. I. Pecci-Maddalena 2017 [printed]\ coccinelloides, Zeitschr. 1870 . Colomb. Wallis [handwritten]”.

Other specimens examined (60)

1 male ( DZUP, dissected) ‘ ColeÇão M . Alvarenga [printed]\ Campos do Jordão , S . Paulo Brasil , I–1969, W . Bokermann [printed]\DZUP 242523 [printed]’; 1 male ( DZUP, dissected) ‘ ColeÇão M . Alvarenga [printed]\ Campos do Jordão , S . Paulo Brasil , I–1969, W . Bokermann [printed]\DZUP 242737 [printed]’; 1 male ( DZUP, dissected) ‘ ColeÇão M . Alvarenga [printed]\ Campos do Jordão , S . Paulo Brasil , I–1969, W . Bokermann [printed]\DZUP 242750 [printed]’; 1 male ( DZUP, dissected) ‘ ColeÇão M . Alvarenga [printed]\ Campos do Jordão , S . Paulo Brasil , I–1969, W . Bokermann [printed]\DZUP 242448 [printed]’; 1 male ( MZSP, dissected) ‘ BRASIL, Itatiáia, Estº R . Janeiro, Col .: DIRINGS [front] FEV 1960 [back] [printed]’; 3 males and 1 female ( CELC, dissected) ‘ VENEZUELA: Mérida, 6 km . S. Azulita , 15 July 1986, R .S. Miller colr’; 27 undissected specimens and 1 female ( FSCA, dissected) (8 nigroterminatus, 10 gemmula, 7 corallipennis, 2 nr. nigricollis, 1 nr. coccoinelloides patterns) ‘ VENEZUELA: Mérida, 6 km . S. Azulita , 15 July 1986, R .S. Miller colr’; 2 males ( FSCA, dissected) ‘ Piletas-Salta , 26 jul-3 ag 44, B . Golbach [handwritten]\ Mycocorallipennis , ex . descr & note [handwritten]\ Mycotretus corallipennis [handwritten], det . P .E . Skelley [printed]’; 12 undissected specimens ( FSCA) ‘ Fazenda Bom Jesus das Araucárias Reserve (PR, Brazil), Cultivo de Pleurotus sp ., P. L. Lopes coll. 18–19 .III .2008 (noon)’; 2 undissected specimens (FSCA) ‘ BRAZIL, Curitiba , Parana, 1–13-1969, C. W. &L.B. O’Brien, Arucaria forest’; 3 undissected specimens ( FSCA) ‘ Brazilia , Petropolis [top] February, F . Sahlberg [underside][handwritten]\ Coll E . Csiki [printed]’; 1 undissected specimen ( FSCA) ‘ Brazilia, Petropolis [front] März, F . Sahlberg [back][handwritten]\ Coll E . Csiki [printed]’; 1 undissected specimen ( FSCA) ‘ Brazilia, Rio Janeiro [top] 1851 . Jan, F. Sahlberg [underside][handwritten]\ Coll E . Csiki [printed]’; 1 undissected specimen ( FSCA) “ Peru [printed] Chanchamyo [handwritten]\[black bordered paper] 364 . 216. [handwritten]; 1 undissected specimen (FSCA) ‘P. Paprzycki , IV-29-1940, Satipo, Peru’ .

Diagnosis

Body oval, TL = 3.48–4.61 mm (4.12 mm, n = 5); clypeus with marginal bead fine and complete across apex; mentum plate variable, from pentagonal to nearly circular in outline; procoxal lines barely visible. Dorsal colouration: head full yellowish to full blackish; thorax with pronotum full blackish or, usually, with two or three yellowish longitudinal, oval, spots; elytra full reddish or reddish and apically blackish. Male genitalia with flagellar head subrectangular or slightly subtriangular. Female with vaginal process shortened, not at the level of gonostyli.

Distribution

Southeast Brazil, Colombia, Peru, Venezuela ( Alvarenga 1994), Argentina ( Figure 55 ).

Nomenclature

The species synonymised here under Mycomystes apicalis are very similar in morphological characters, body colour and shape. We observed that the pronotal colour patterns and the black elytral apical spot change according to the degree of body pigmentation. Unlike M. melanophthalmus , that has distinct colour patterns (see below), the colouration in M. apicalis seems to change continuously expressing many intermediate forms. Two large series of specimens from different countries possessed multiple named synonyms. One collection from Venezuela (Mérida) possessed five named synonyms with intermediate pattern variations. The second from Brazil (Araucárias Reserve, Paraná) on cultivated Pleurotus sp. , possessed at least three named synonyms with intermediate colour patterns. We dissected individuals with all colour patterns shown in the Figure 19–27 and, despite these differences, the external morphological features (dorsal and ventral) and the male and female terminalia have the same morphology.

Remarks

Lacordaire (1842) described Mycotretus pulicarius as a bona species and did not define it as a ‘variety’ of M. gemmula (which was described by him in the same work). Crotch (1876) included M. pulicarius under M. gemmula and only stated that M. pulicarius ‘ has the disc of the thorax black’. After that, possibly based on Crotch’s comments, authors have considered M. pulicarius as a ‘variety’ of M. gemmula (see Mader 1942; Blackwelder 1945; Alvarenga 1994). However, it is not clear whether Crotch considered M. pulicarius as a variety or not.

There were two unlabelled specimens, apparently conspecific with M. corallipennis , close to the lectotype in the UMZC collection. However, we are not sure whether they are syntypes.

Although a mentum with a nearly rounded lateral outline seems to be the most common pattern observed in the examined specimens, one examined individual and the lectotypes of Mycotretus apicalis and Mycotretus gemmula (transferred to Mycomystes ) have a pentagonal mentum. That observation suggests that the ‘mentum outline’ in individuals of M. apicalis would be a continuous character. However, a more complete taxon sampling is necessary to confirm this.

Natural history

Moreira et al. (2010a) reported Mycomystes apicalis causing injury in cultivations of Pleurotus sajor-caju (Pleurotaceae) , an edible fungus species. We have not examined vouchers from this study to confirm their identity. However, we have confirmed M. apicalis and two other species of Mycomystes from cultivated Pleurotus .

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).

Figures 1-12. Generic diagnostic characters of Mycomystes Gorham, 1888: (1) Head of M. peruvianus (Kirsch, 1876), arrow showing the complete clypeal marginal bead. (2) Subgenal braces of M. coccineus (Lacordaire, 1842), arrow showing the inner carina. (3) Partial view of the mouthparts of M. coccineus, big arrows showing the apical maxillary palpomeres and small arrow showing an apical labial palp. (4) Right mandible of M. nigriventris Pecci-Maddalena and Lopes-Andrade,2020, arrow showing the teeth. (5–6) Mentum plate of M. coccineus and M. melanophthalmus (Duponchel, 1825), respectively. (7) Partial view of the pronotum and elytra of M. apicalis (Lacordaire, 1842), arrows showing the basal elytral marginal bead. (8–9) Mesotibia of M. apicalis and M. melanophthalmus, respectively. (10–11) Metendosternite of M. melanophthalmus and of a male of M. coccineus, respectively,arrow in Figure 10 showing the anterior tendon. (12) Abdomen of M. peruvianus, arrows showing the coxal lines. Scale bars: 0.1 mm (2, 4–6, 10–11); 0.25 mm (8–9); 0.5 mm (3, 7).

Figures 13-18. Genitalia of Mycomystes Gorham, 1888: (13–16) Male flagellar head of M. apicalis (Lacordaire, 1842), M. coccineus (Lacordaire, 1842), M. melanophthalmus (Duponchel, 1825), M. nigriventris Pecci-Maddalena and Lopes-Andrade, 2020, respectively. (17–18) Female genitalia of M. nigriventris and M. coccineus, respectively, arrows showing the vaginal process. Scale bars: 0.1 mm (13–17).

Figures 19-27. Specimens of Mycomystes apicalis (Lacordaire, 1842): (19–21) Lectotype (MNHN) of Mycotretus apicalis, here transferred to Mycomystes. (22) Mycotretus corallipennis Crotch, 1876, new synonym, lectotype (UMZC). (23) Mycotretus gemmula Lacordaire, 1842, new synonym, lectotype (MNHN). (24) Mycotretus gentilis Lacordaire, 1842, new synonym, lectotype (MNHN). (25) Mycotretus nigroterminatus Lacordaire, 1842, new synonym, lectotype (MNHN). (26) Mycotretus pulicarius Lacordaire, 1842, new synonym, lectotype (MNHN). (27) Mycotretus coccinelloides Taschenberg, 1870, new synonym, lectotype (ZNS). Scale bars: 1 mm (19, 21–26); 0.5 mm (20).