Systematics of the Ceracis furcifer Species-Group (Coleoptera: Ciidae): The Specialized Consumers of the Blood-Red Bracket Fungus Pycnoporus sanguineus

Abstract

The Ceracis furcifer species-group (Coleoptera: Ciidae) originally comprised nine species names: Ceracis cornifer (Mellié, 1849); C. cylindricus (Brèthes, 1922); C. furcifer Mellié, 1849; C. hastifer (Mellié, 1849); C. monocerus Lawrence, 1967; C. ruficornis Pic, 1916; C. simplicicornis (Pic, 1916); C. semipallidus Pic, 1922 and C. unicornis Gorham, 1898. Ceracis semipallidus was synonymised with C. furcifer and then no further changes were made to the composition of the group. Here, we provide a taxonomic revision of the Ceracis furcifer species-group and new data on the geographic distribution and host fungi of the included species. Lectotypes are designated for C. cornifer, C. furcifer, C. hastifer, C. ruficornis, C. semipallidus and C. unicornis. As results we: (i) synonymise C. cylindricus, C. monocerus, C. simplicicornis, C. unicornis with C. cornifer; (ii) confirm the synonymy of C. semipallidus with C. furcifer; (iii) redescribe C. cornifer, C. hastifer, C. furcifer and C. ruficornis; and (iv) provide an identification key for species in the furcifer group. The frontoclypeal horn and body coloration showed great intraspecific variation. We show that species in the furcifer group have distributions wider than previously known and use mainly Pycnoporus sanguineus as host fungus. Species of the furcifer group are the only animals specialized in feeding on basidiomes of P. sanguineus.

Keywords: Neotropical; host fungus; minute tree-fungus beetles; specialization.

Figure 1

Pycnoporus sanguineus (L.) Murrill, host fungus of species of the furcifer group. (A) Basidiomes at a garden in Juiz de Fora, Minas Gerais (MG), Brazil. (B) A male of C. cornifer (Mellié) species on a P. sanguineus basidiome from Serra do Cipó, MG, Brazil. C−D Basidiomes colonized (C) by individuals of Ceracis cornifer (Mellié) from Juiz de Fora (arrows indicating the presence of two) and (D) by individuals of Ceracis furcifer Mellié from Araguaína, Tocantins (TO), Brazil (arrows). Figure 1D, scale bar = 0.5 mm.

Figure 2

Distribution map for species of the furcifer group. The doubtful record of Ceracis hastifer (orange star) is based on individuals from São Roque (São Paulo (SP), Brazil). Note: the distribution of C. cornifer is disjunct. Overlapping symbols represent localities where two species are sympatric: C. cornifer and C. furcifer in Paranhos (Mato Grosso do Sul (MS), Brazil) and Serra do Cipó (MG, Brazil); C. furcifer and C. hastifer in San Luis de Palenque (Casanare, Colombia) and Marabá (Pará (PA), Brazil); and C. ruficornis and C. cornifer in Paraty (Rio de Janeiro (RJ)), Ilha da Vitória (SP) and Peruíbe (SP), Southeast Brazil.

Figure 3

Ceracis cornifer (Mellié). A−E Male lectotype, (A) dorsal, lateral and ventral views, respectively. Frontoclypeal horn subtruncate at apex (black arrow) and laminate in lateral view (red arrow); prosternal process thin but not laminate (white arrow), (B) pronotal punctation, (C) first abdominal ventrite with a sex patch at the centre (white arrow), (D) male terminalia, showing sternite VIII (with a deep concave emargination at middle, black arrow), tegmen (teg), penis (pen, basal edge blunts; black arrows), (E) labels of the lectotype deposited in the Muséum National d’Histoire Naturelle, MNHN (Paris, France), (F) female plesiotype from Viçosa (MG, Brazil). Scale bars: A = 0.5 mm, B = 0.2 mm, C,D = 0.1 mm, F = 0.5 mm.

Figure 4

Ceracis cornifer (Mellié, 1849), SEM under variable pressure and without any sputter-coating of male specimen from Ubá (MG, Brazil). (A) Prosternal process thin but not laminate (white arrow), (B) first abdominal ventrite with a sex patch (white arrow). Scale bars: A = 0.03 mm, B = 0.01 mm.

Figure 5

Male morphs of species of the furcifer group from different localities. A−H Ceracis cornifer (Mellié), (A) lectotype from Brazil, (B) Florida, United States of America, (C) Urubici, SC, Brazil, (D) Juiz de Fora, MG, Brazil, (E,F) Jequeri, MG, Brazil, (G) São Francisco de Paula, RS, Brazil, (H) Tucuman, Argentina. I,J Ceracis furcifer Mellié, (I) Paranhos, MS, Brazil, (J) Colombia. K,L, Ceracis hastifer (Mellié), (K) lectotype from Colombia, (L) Colombia. M,N Ceracis ruficornis Pic, (M) Peruíbe, SP, Brazil, (N) Ilha dos Búzios, SP, Brazil. Scale bar: 0.1 mm.

Figure 6

Colour variation in individuals of Ceracis cornifer (Mellié). (A) Localities in a temperature map (in Celsius degrees): (i) Viçosa, MG (Brazil), (ii) Ilha da Vitória, SP (Brazil), (iii) Peruibe, SP (Brazil), (iv) Urubici, SC (Brazil), (v) São Francisco de Paula, RS (Brazil), (vi) Wanda, Misiones (Argentina), (vii) Paranhos, MS, Brazil. (B) Specimens from the southern tip of the distribution. (C) Coloration black and reddish-brown. (D) Original description of C. simplicicornis Pic (new synonym of C. cornifer proposed here) from Buenos Ayres as “nigro-piceus”.

Figure 7

Ceracis furcifer Mellié. A−C Male lectotype, (A) dorsal, lateral and ventral views, respectively. Horn apex with two conspicuous rounded lobes (black arrow); thin prosternal process (white arrow), (B) pronotal punctation, (C) first abdominal ventrite with a sex patch at centre (white arrow), (D) male terminalia in a topotype, showing sternite VIII with a deep concave emargination at middle (black arrow), tegmen (teg), penis (pen) with the basal edge blunt (black arrows), (E) labels of the lectotype deposited in the Muséum d’Histoire Naturelle, MHNG (Géneve, Switzerland), (F) female plesiotype from Manaus (AM, Brazil). Scale bars: A = 0.5 mm, B−D = 0.1 mm, F = 0.5 mm.

Figure 8

Colour variation in specimens of Ceracis furcifer Mellié. (A) Colour variation among individuals from a single locality (Paranhos, MS, Brazil), arrow showing specimen “half brown, half dark-brown”. (B) A specimen from Mambaí (GO, Brazil) showing an intermediate colour in comparison to specimens shown in A and C. (C) A teneral (right) and homogeneously black individual (left, black arrow) from Araguaína (TO, Brazil). Scale bar: 0.5 mm.

Figure 9

Ceracis hastifer Mellié. A−C Male lectotype, (A) dorsal, lateral and ventral views, respectively. Frontoclypeal ridge strongly produced forming a long and narrow upward directed median horn (black arrow); laminate in lateral view (red arrow); prosternal process thin (white arrow), (B) pronotal punctation, (C) first abdominal ventrite with a sex patch at the centre (white arrow), (D) male terminalia in a paralectotype, showing sternite VIII with a deep concave emargination at the middle of the posterior edge (black arrow); tegmen (teg), penis (pen) with membranous apical and basal portion (arrow), (E) labels of the lectotype deposited in the Muséum d’Histoire Naturelle, MHNG (Géneve, Switzerland), (F) female plesiotype from Peru. Scale bars: A = 0.5 mm, B−D = 0.1 mm, F = 0.5 mm.

Figure 10

Ceracis ruficornis Pic. A−C Male plesiotype, (A) dorsal, lateral and ventral views, respectively. Frontoclypeal ridge strongly produced forming a long horn (black arrow); laminar in lateral view (red arrow); prosternal process thin (white arrow), (B) pronotal punctation, (C) first abdominal ventrite with a sex patch at the centre (white arrow), (D) terminalia of a male from Bertioga, SP, Brazil, showing sternite VIII, with a deep concave emargination at the middle of the posterior edge (arrow), tegmen (teg), penis (pen) with basal edge blunt (arrows), (E) female plesiotype from Praia da Boraceia (SP, Brazil), (F) male lectotype deposited in the Muséum National d’Histoire Naturelle, MNHN (Paris, France). Scale bars: A = 0.5 mm, B−D = 0.1 mm, E,F = 0.5 mm.

Figure 11

Characters for the identification of males of the Ceracis furcifer species-group. See 3.2.5. Identification key above for explanations.