Redescription of two species and proposal of a new synonym in the genus Mycotretus Lacordaire, 1842 (Coleoptera: Erotylidae: Tritomini) 

Abstract

Mycotretus Lacordaire, 1842 is a Neotropical genus of beetles, being the second most speciose genus within Erotylidae. The older descriptions of Mycotretus species are anecdotal and none include information on male and female genitalia, which can have great taxonomic value. Our objective in the present work is to redescribe Mycotretus chilensis Crotch, 1876 and Mycotretus trifasciatus Guérin, 1956 providing the first descriptions of their mouthparts, metendosternite, male and female terminalia, as well as new data on their geographic distribution and host fungi. Additionally, the lectotype of M. chilensis is designated and Mycotretus bicinctus Guérin, 1949 is proposed as a new junior synonym of M. chilensis. Both M. chilensis and M. trifasciatus have great intraspecific variation and are sympatric or syntopic in a few localities. We conclude that morphological differences of the penial flagellum and the metendosternite can be used to diagnose species and may also have phylogenetic signal for Mycotretus species. The present work is our first step in an ongoing taxonomic revision of the genus Mycotretus.

Redescriptions, Lectotype Designations, New Synonyms and New Geographic Records for the “Tiger” Species of Mycotretus Lacordaire, 1842 (Coleoptera: Erotylidae: Tritomini)

“…Dissection, photography and measurement of specimens followed the methods provided by Pecci-Maddalena and Lopes-Andrade [3]. Transcription of labels followed Pecci-Maddalena and Lopes-Andrade [11].…”

“…The Neotropical Mycotretus Lacordaire, 1842 is one of the largest genera in the family Erotylidae, encompassing more than 200 described species widespread in the Neotropical region [1,2,3]. The genus is taxonomically problematic as most species are known only from older descriptions [1,4,5], information about male and female terminalia is scarce [3,6,7], and no taxonomic revision has been provided to date. Data on host fungi of Mycotretus are scarce and records are too few to discuss host fungus specialization.…”

“…Data on host fungi of Mycotretus are scarce and records are too few to discuss host fungus specialization. Most other Erotylinae species of Mycotretus feed on basidiomycete fungi, with host records in the families Pleurotaceae, Polyporaceae and Mycenaceae [3]. There are records of two different species of Mycotretus co-occurring in the same host fungus, for instance in the case of M. chilensis Crotch, 1876 and M. trifasciatus Guérin, 1956 co-occurring in the fungi Mycena sp.…”

“…There are records of two different species of Mycotretus co-occurring in the same host fungus, for instance in the case of M. chilensis Crotch, 1876 and M. trifasciatus Guérin, 1956 co-occurring in the fungi Mycena sp. (Mycenaceae) and Lentinus brumalis (Polyporaceae) [3].…”

“…Dorsal color patterns are extremely variable in Mycotretus , ranging from completely monochromic to species with several spots, bands or stripes, especially on the pronotum and elytra [1,3]. Among Mycotretus there is an assemblage of six valid species—called the “tiger” Mycotretus from now on in the text—recognized by the presence of many pronotal and elytral black spots, usually sparsely distributed in no discernable pattern, as follows: M. tigrinus (Olivier, 1792); M. multimaculatus Taschenberg, 1870; M. centralis Arrow, 1909; M. tigrinoides Mader, 1942; M. tigripennis Mader, 1942; and M. prioteloides Mader, 1942.…”