Aegidinus guianensis (Westwood, 1845)

Frolov, Andrey V., Akhmetova, Lilia A. & Vaz-de-Mello, Fernando Z., 2019, Contribution to the knowledge of Aegidinus Arrow (Coleoptera: Scarabaeidae: Orphninae): new species and comments on the classification and nomenclature, Journal of Natural History 53 (11), pp. 725-747 : 733-734

Aegidinus guianensis (Westwood, 1845)

( Figure 1 (a–i))

Aegidium guianense Westwood, 1845: 175

= Aegidinus oreibates Colby, 2009: 26 , syn. nov.

= Aegidinus crypticus Colby, 2009: 20 , syn. nov.

Type locality. Guyana, Upper Takutu-Upper Essequibo.

Type material examined

Aegidium guianensis : holotype ( Figure 1 (a)), female at OUMNH labelled ‘ Guiana / Aegidium ? Guianense Westw ./TYPE WESTWOOD Trans. Ent. Soc L.1846.P.175 T. 12. 8. 5. Coll. Hope Oxon./TYPE COL: 488 Aegidium guianensis Westw. HOPE DEPT. OXFORD/ W/WB ’.

Aegidium oreibates : holotype ( Figure 1 (f)), male at CMN labelled ‘ TRINIDAD: ST. GEORGE 8 km N. Arima, Simla Res. Sta., 260 m, 14 – 24.VI.1993 S. & J. Peck, lower mont. rainforest, f.i.t., 93 – 48/ Aegidinus oreibates Colby HOLOTYPE ’. Paratypes: GUYANA. Potaro-Siparuni: one female at CMN labelled ‘ Guyana: Iwokrama F. R. 4°40 ʹ 19N 58° 41 ʹ 04W 100 – 200 m, V-VI.2001 R.Brooks & Z.Falin in FIT/ Aegidinus oreibates J. Colby PARATYPE ’. TRINIDAD AND TOBAGO. One female at IRSNB labelled ‘ ♀ /Coll. R. I. Sc. N. B. Caparo Trinidad A. Heyne, Berlin-Wilm./ Aegidinus oreibates Colby PARATYPE / Paratype / Aegidinus guianense Westw ♀ E. Benderitter, det ’. Arima: one male at CMN labelled ‘ TRINIDAD, 16 km N Arima Andrews Trace, 620m up. montane rainforest FIT, 7 – 24.VI.1993 S&J Peck, 93 – 14/ PARATYPE Aegidinus oreibates J. Colby ’; one male at CMN labelled ‘ TRINIDAD, 8 km N Arima Simla Res. Sta. 260m 24.VI – 8.VII.93, lower montane rainforest FIT S&J Peck, 93 – 57/ Aegidinus oreibates J. Colby PARATYPE ’; one female at CMN labelled ‘ TRINIDAD: ST. GEORGE 8 km N. Arima, Simla Res. Sta., 260 m, 14 – 24. VI.1993 S. & J. Peck, lower mont. rainforest, f.i.t., 93 – 48/ Aegidinus oreibates Colby ALLOTYPE ’; one male and two females at CMN labelled ‘ TRINIDAD: ST. GEORGE 8 km N. Arima, Simla Res. Sta., 260 m, 14 – 24.VI.1993 S. & J. Peck, lower mont. rainforest, f.i.t., 93 – 48/ Aegidinus oreibates Colby PARATYPE ’; two males and one female at CMN labelled ‘ TRINIDAD, 8 km N Arima Simla Res. Sta. 260m 6 – 14.VI.93 trop. forest FIT S&J Peck, 93 – 9/ PARATYPE Aegidinus oreibates J. Colby ’. Couva-Tabaquite-Talparo: one male at CMN labelled ‘ TRINIDAD, 11 km SE Arima, Arena For. Res. 13 – 22.VI.93, 80m rainforest FIT S&J Peck, 93 – 30/ PARATYPE Aegidinus oreibates J. Colby ’; one male at CMN labelled ‘ TRINIDAD, 13 km S Arima 2km N Talparo, Quesnell Farm, rainforest FIT 12 – 22.VI.93, 50m S&J Peck, 93 – 28/ PARATYPE Aegidinus oreibates J. Colby ’. VENEZUELA. Bolívar: one female at CMN labelled ‘ VENEZUELA: BOLIVAR Guri, 14.VI.1996 H.&A. Howden Dry forest L +/ Aegidinus oreibates J. Colby PARATYPE ’.

Additional material examined

VENEZUELA. Bolívar: Guri, dry forest, 14 June 1996, H. Howden and A. Howden leg., one female ( CEMT); Guri, wet forest, 17 June 1996, B.D. Gill leg., one female ( BGCO). TRINIDAD AND TOBAGO. 11 km SE Arima, Arena Forest Reserve, 80 m, rainforest, FIT, 13 – 22 June 1993, S. Peck, J. Peck leg., one male ( BGCO); 8 km N Arima, Simla Research Station, 260 m, lower mountane rainforest FIT, 6 – 14 June 1993, S. Peck, J. Peck leg., one male ( BGCO); 16 km N Arima, Andrews Trace, 620 m, upper montane rainforest, FIT, 24 June – 7 July 1993, S. Peck, J. Peck leg., one male ( BGCO); 8 km N Arima, Simla Research Station, 260 m, lower montane rainforest, FIT, 24 June – 8 July 1993, S. Peck, J. Peck leg., one female ( BGCO). GUYANA. Potaro-Siparuni: Pataro-Siparuni Iwokara Rain Forest, 70 m, human faeces baited, 13 April – 31 May 2009, S. Phelps leg., one female ( OUMNH). SURINAME. Road to Amotopo, km 39, unbaited pitfalls, secondary forest, 29 May – 2 June 1981, J. Huijbregts leg., one female ( RMNHL); Sipaliwini W-bank Suriname River opposite Pingpe 4.041667° N, 55°45 W, FIT in forest, 25 January – 1 February 2012, M.A. Hielkema leg., one female ( RMNHL); road to Amotopo, km 34, primary forest, pitfalls baited with human dung, 28 May – 1 June 1981, J. Huijbregts leg., one female ( RMNHL). FRENCH GUIANA. Mont Grand Matoury, 24 January 2013, SEAG leg., two females ( ZIN); 7 January 2013, SEAG leg., one male ( ZIN); Gourdonville, 1905, E. Le Moult leg., one male and one female ( MNHN). BRAZIL. Roraima: Cariri, Vila Napoleão, 4 May 1972, J. Celso leg., one male ( CEMT); 10 April 1972, J. Celso leg., one female ( CEMT). Pará: Belém, one female ( MNHN) .

Diagnosis

Aegidinus guianensis is most similar to Ae. howdenorum but differs from it in having the ventrolateral lobe of the parameres without a subapical tooth ( Figure 1 (h)). From other Aegidinus species it differs in having the phallobase with a ventroapical plate and symmetrical parameres ( Figure 1 (g,i)).

Remarks

Paulian (1984) and Colby (2009) drew male characters of Ae. guianensis from the type of Ae. steinheili , which was considered a synonym of Ae. guianensis after Arrow (1904). Colby (2009) erroneously considered the female specimen with the label ‘ Cayenne ’, housed in BMNH, to be the holotype of Ae. guianensis and drew the female characters from it. This specimen, in our opinion, belongs to Ae. howeae Colby or Ae. brasiliensis , but it lacks the abdomen and genitalia. Ae. guianensis was described from British Guiana (nowadays Guyana) and the holotype of it is housed in OUMNH ( Figure 1 (a,b)). It agrees with the original description of the species, and its mouthparts were dissected and illustrated by Westwood (1845, pl. XII, fig. 5). The specimen was likely collected by Robert Schomburgk in Pirara on the shores of Lake Amucu (Darren Mann, pers. comm.).

By the shape of the female genitalia and external morphological characters, the type of Ae. guianensis ( Figure 1 (a,d)) cannot be distinguished from Ae. oreibates Colby ( Figure 1 (c,e)), described from a long series mostly from the Guiana Shield and the island of Trinidad. For this reason, we propose that Aegidinus oreibates Colby is a synonym of Aegidium guianense Westwood. Because this long series includes both sexes, the male characters of Ae. guianensis can be reliably based on the males from this series.

Ae. crypticus Colby was described from Guyana from a single male specimen. The difference between Ae. oreibates and Ae. crypticus is, according to the author, that in the latter species the median lobes of the parameres are longer and thinner and the shape of the ventral plate of phallobase at the apex is much rounder ( Colby 2009). However, the detailed photographs of the parameres provided in the original descriptions ( Colby 2009, figs 46 – 49, 59 – 60) show that these characters are not diagnostic: the median lobes of the parameres are of about the same length and width and the ventral plates are equally rounded. The differences between the photographs are due to the slightly different angle of view and because the illustrated parameres of Ae. oreibates are opened while those of Ae. crypticus are close to each other. Therefore, we propose that Aegidinus crypticus Colby is also a synonym of Aegidium guianense Westwood.

Figures

Figure 1. Aegidinus guianensis, holotype, female (a, b, d), female, paratype of Ae. oreibates (c), female from Villa Napoleão, Brazil (e), male, holotype of Ae. oreibates (f), male, paratype of Ae. oreibates (g–i). Habitus in dorsal view (a, c, f), labels (b), female external genitalia (d, e), aedeagus in lateral (h) and ventral view (g), parameres in dorsal view (i).