Aegidium cribratum Bates, 1887

Frolov, Andrey V., Akhmetova, Lilia A. & Vaz-de-Mello, Fernando Z., 2017, Revision of the mainland species of the Neotropical genus Aegidium Westwood (Coleoptera: Scarabaeidae: Orphninae), Journal of Natural History 51 (19 - 20), pp. 1035-1090 : 1082-1085

Aegidium cribratum Bates, 1887

( Figures 17 (a–f and 18(a–c))

Aegidium colombianum var. cribratum Bates 1887: 105

Aegidium colombianum var. cribratum Bates : Arrow 1903: 515, 1912: 31

Aegidium asperatum Preudhomme de Borre : Schmidt 1913: 70; Blackwelder 1944: 217

Aegidium cribratum Bates : Paulian 1984: 74

Aegidium colombianum var. squamatum Bates, 1887: 105 , syn. nov.

Type locality

Panama, Chiriquí, Volcán.

Type material examined

Aegidium cribratum : lectotype, male ( Figure 17 (a,c,d)) at BMNH labeled ‘V. de Chiriqui, 25–4000 ft. Champion ./ Aegidium colombianum v. cribratum Bates / Aegidium cribratum Bates R. Paulian det./B.C.A., Col ., II(2)./ Sp . figured./ LECTOTYPE /LECTOTYPE’. Paralectotypes: PANAMA. Chiriquí: one female at MNHN labeled ‘V. de Chiriqui, 25–4000 ft. Champion ./Ex Musaeo H.W.BATES 1892/MUSEUM PARIS / Aegidium cribratum Bates /G. J. Arrow Vidit 1903./PARALECTOTYPE’; one female at BMNH labeled ‘V. de Chiriqui, 25–4000 ft. Champion ./Sp. figured./ Aegidium colombianum v. cribratum ♀ Bates / Aegidium cribratum Bates R. Paulian det./B.C.A., Col .,II(2)./PARALECTOTYPE’; one female at BMNH labeled ‘V. de Chiriqui, 25–4000 ft. Champion ./ v. cribratum /B.C.A., Col .,II (2)./PARALECTOTYPE’.

Aegidium squamatum : lectotype, male ( Figure 18 (a–c)) at BMNH labeled ‘ Chontales. Janson/ Aegidium squamatum Bates / Aegidium squamatum Bates R. Paulian det./B.C.A.,Col., II(2)./ LECTOTYPE /LECTOTYPE’. Paralectotypes: NICARAGUA. Chontales: one female at BMNH labeled ‘ Chontales Janson / Aegidium squamatum Bates /B.C.A.,Col.,II(2)./ PARALECTOTYPE’; one male at MNHN labeled ‘ Chontales. Janson/ Aegidium squamatum Bates /G. J. Arrow Vidit 1903./H.W.Bates Biol.Cent.Amer./ PARALECTOTYPE /MUSEUM PARIS’.

Additional material examined

BELIZE. Cayo: one male at OUMNH, Chiquibul Forest Reserve, Las Cuevas Research Station , un-baited pitfall, 3–10 August 2001, G.C. McGavin leg. COSTA RICA. Puntarenas: two females at CMN, Monte Verde, FIT, 25 June-2 July 1983, D.H. Lindeman leg. One male at BMNH, Carablanca ; one male at MNC, Cerro Saslaya, 250–300 m, 6–10 May 2011, B. Hernandez leg.; one female at MNC, Cerro Saslaya, 800 m, forest, 7–14 July 1999, B. Hernandez leg.; one male at CMN. GUATEMALA. Alta Verapaz: one male at CMN, Sepacuité, on trail, 26 July 1969, S. Peck and J. Peck leg. Zacapa: one female at BGCO, 3 km S La Union , 1400 m, 4 June 1991, B.D. Gill leg. MEXICO. Chiapas: one female at CEMT, Boca de Chajul, 110 m, semi-evergreen forest, rotten trunk, 3 October 1984, M.A. Morón, C. Fragoso and F.J. Villalobos leg.; one female at CEMT, Chajul, Ocosingo, Biological Station , August 2006, J. Bueno and C. Sormani leg.; one female at HNHM, Chajul, Selva Lacandona, UNAM Biological Station , 150 m, beneath bark, 25 June 1996, S. Mahunka and A. Borhidi leg.; one female at CMN, El Rosario Izapa, Tacaná Volcano, May 1963, Martinez leg.; one female at CMN, Palenque, rainforest FIT, 100 m, 2–30 July 1983, S. Peck, J. Peck and R. Anderson leg.; one male at CEMT, Unión Juárez, San Rafael, 1100 m, coffee plantation, in stem of rotten banana, 25 August 1981, P. Reyes et al. leg. Oaxaca: one female at CMN, Palomares, 25.V.1959, C. Bolivar leg. Veracruz: one male at CNCI, 2.5 miles W Sontecomapan , 33 m, leaf litter, 1–5 June 1966, G.E. Ball and D.R. Whitehead leg.; one female at CMN, 33 km N Catemaco, Los Tuxtlas Biology Station , 22–29 June 1984, D.H. Lindeman leg.; one male and one female at CMN, 33 km N Catemaco, Los Tuxtlas Biology Station , FIT, 22–29 June 1984, D.H. Lindeman leg.; one female at CNCI, Coyame, Catemaco lake , 1–15 July 1963, D.R. Whitehead leg.; one female at CMN, Quezalapan River , 2 mi E of Catemaco Lake, 12 August 1964, J.R. Meyer leg. NICARAGUA. Jinotega: one male and three females at MNC, Cerro Kilambé, 1000 m, August 2001, M. A. Guatemala leg. Matagalpa: one male at MNC, Cerro Musún [?], July 2011, B. Hernandez leg. PANAMA. Chiriquí: one male and two females at BGCO, Cerro Pelota, 4 km N Santa Clara , 1500 m, 15–30 July 1982, B. Gill leg.; one female at BGCO, La Fortuna Dam, 1200 m, 12 September 1982, B. Gill leg.; one male at OUMNH, Lost and Found Eco Lodge, near Valle de la Mina, 1255 m, at light, March 2011, R. Wallace leg.; one male at MNHN, Volcán, 1901, M. de Mathan leg. Panamá: one female at CNCI, Ciricito, 3 March 1930 .

Diagnosis

Aegidium cribratum is most similar to Ae. asperatum and can be separated from it largely by the sparser punctation of the elytra ( Figures 17 (a,b) and 18(a)).

Description

Male ( Figures 17 (a,c–e) and 18(a–c)). Body length 10.5–17.0 mm. Colour uniformly blackish brown.

Anterior margin of frontoclypeus slightly convex in middle, slightly sinuate each side of medial convexity, angulate laterally, without distinct border or slightly upturned. Frontoclypeus punctate with rounded punctures separated by about 1 puncture diameter.

Eyes relatively large: width about 1/7 distance between eyes in dorsal view.

Pronotum with widely rounded lateral margins, slightly wider than elytra, 1.6 times wider than length, 0.55 times length of elytra. Posterior angles widely rounded, indistinct. Anterior margin bordered, border interrupted medially and not reaching anterior angles. Base of pronotum without furrow, punctate with a row of large, rounded, punctures separated by about 1–2 puncture diameters. Pronotal disc deeply excavated, with flattened to slightly convex area mediobasally. Lateral pronotal processes long, horn-shaped in lateral view, slightly protruding past lateral margin outline of pronotum in dorsal view. Medial excavation of pronotum punctate with elongate punctures, lateral processes almost smooth, covered with a few rounded punctutes.

Scutellum narrow subtriangular, about 1/11 length of elytra.

Elytra 1.2 times longer than wide, with humeral and apical umbones. Elytra widest in basal 1/3, tapering apically in dorsal view. Elytral carinae feebly distinct. Elytra covered with relatively elongated punctures.

Macropterous.

Mesotibiae without tuft of setae ventroapically. Inner apical spur of mesotibia shorter than basal mesotarsomere and not curved downwards.

Aedeagus with relatively long (0.55 times length of phallobase), tapering parameres ( Figures 17 (c) and 18(b)). Parameres almost as wide as apical part of phallobase in dorsal view ( Figures 17 (d) and 18(c)). Ventrobasal transverse plate of parameres distinct. Lateral teeth of parameres feebly or not protruding past paramere outline in dorsal view ( Figures 17 (d) and 18(c)). Endophallus without strongly sclerotised sclerites. Cranial part of spiculum gastrale narrow, tapering and rounded apically ( Figure 1 (e)).

Female ( Figure 17 (b)) differs from male in having protibial spur, relatively smaller pronotum without armature and in absence of inner protibial tooth. Body length 10.0– 14.0 mm.

Variation

In addition to body size variation, examined males vary in the shape of the pronotum and its armature. In the examined material there are specimens with shallow excavation on pronotum medially and a small rounded anteromedial tubercle, and intermediate forms between it and specimens with fully developed pronotal armature.

Distribution

Aegidium cribratum is distributed in Central America, from southern Mexico to Panama ( Figure 17 (f)). Records of this species from South America ( Paulian 1984) pertain to Ae. gilli sp. nov. (Caracas) and probably to Ae. asperatum ( Colombia) . Description of Ae. cribratum chileanum Paulian from Chile (without precise locality) was based apparently on mislabeled specimens.

Remarks

Aegidium cribratum and Ae. squamatum were described in the same paper ( Bates 1887) as varieties of Ae. columbianum . Bates wrote that in the later variety ‘the flat scales in the punctures... are very conspicuous, and give a tawny-brown tint to the whole body’ ( Bates 1887: 105). Paulian (1984) treated both varieties as distinct species and separated them, in the key, by the ‘simple or rough’ punctation of the mesepimera in Ae. squamatum and punctation as ‘transverse or longitudinal lines’ in Ae. cribratum . Comparison of the types showed us that the differences in the sculpture mentioned by Paulian are within the limits of interspecific variation found in other Aegidium species. Otherwise the types of Ae. squamatum and Ae. cribratum are similar in all characters including the genitalia, and thus the new synonymy is here proposed. The ‘brown scales’ of Ae. columbianum var squamatum , mentioned by Bates, are in fact the punctures of the upper side of the body contaminated with soil. It should also be noted that the illustrations of the parameres of Ae. cribratum provided by Paulian (1984, figures 38 and 39) do not agree with the parameres of this species and probably belong to Ae. columbianum .

Figures

Figure 1. Aegidium angustum, holotype male (a,b, d, e,f), paratype female (c). Habitus in dorsal view (a, c), labels (b), aedeagus in lateral view (d), parameres in dorsal view (e), spiculum gastrale (f), locality map (g).

Figure 17. Aegidium cribratum, lectotype male (a, c, d), male (e), female (b). Habitus in dorsal view (a, b), aedeagus in lateral view (c), parameres in dorsal view (d), spiculum gastrale (e), locality map (f).

Figure 18. Aegidium cribratum, lectotype of Aegidium colombianum var. squamatum, male. Habitus in dorsal view (a), aedeagus in lateral view (b), parameres in dorsal view (c).