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

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.