Proceedings of the United States National Museum SMITHSONIAN INSTITUTION • WASHINGTON, D.C. Volume 117 1965 Number 3515 REVISION OF DIAPERINI OF AMERICA NORTH OF MEXICO WITH NOTES ON EXTRALIMITAL SPECIES (COLEOPTERA: TENEBRIONIDAE) By Charles A. Triplehorn ^ Introduction In the family Tenebrionidae, the darkling beetles, is a group of genera which centers around the enormous and cosmopolitan genus Platydema. This group has been recognized as a natm-al one for a long period (see history of the group below), and has been referred to variously as a family, a subfamily, and a tribe. For reasons which will become evident later, I propose to regard it as a tribe, Diaperini, in the subfamily Tenebrioninae. Various elements have been shuttled in and out of the Diaperini by different authors and a number of classifications have been pro- posed. Numerous attempts have been made in the past to define the limits of the tribe, but most of these were based solely on the fauna of a particular region and, when expanded to embrace the world fauna, were found to be quite deficient. As usual, the earlier works were based for the most part on the European fauna. For- tunately the Nearctic fauna is comparable to that of the Palaearctic region, so that both fit the system reasonably well. ' Department of Zoology and Entomology, Ohio State University, Columbus, Ohio. 349 350 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 In beginning a study of the North American Tenebrionidae, one's initial impression of the Diaperini is that it forms a taxonomically soimd group. This was my own feeling on the matter when I re- viewed the Ohio species of the family (Triplehorn, 1952). Later, as I began to extend my studies to include the western and southern elements, I soon realized that the group actually was poorly under- stood. Several extraneous components were present, tribal limits were ill-defined, a number of names of vmcertain validity were scat- tered through the literature, several new species needed to be de- scribed, and a certain amount of synonymy was involved among existing species. Moreover, it was evident that despite Champion's excellent work on the Central American fauna, the Nearctic and Neotropical components of the tribe had been compared by him only superficially. Thus, the problem, which resulted in this report, was suggested. It was decided to review critically the limits of the group on a world- wide basis, to attempt to establish its taxonomic position, and to re- vise the North American Diaperini in light of om' present knowledge of the world fauna. A number of impediments are immediately apparent. Most of the types of the North American species are m European museums and are inaccessible if, indeed, they still exist. Representative collections from all faunal areas would be impossible to assemble, study, and compare in the time allocated. Certain areas of the world, notably South America, are so rich in new species that too much time would be expended simply in describing the new species encountered. The scope of the problem has therefore been modified to a revision of the North American components of the tribe, supplemented by re- marks on the Neotropical and Palaearctic species that were available. Virtually no material was seen from other extralimital areas, but the taxonomic treatments of such areas as Australia, West Africa, and the Indo-Malayan region were consulted for information regarding the higher categories. HiSTOKY OF THE GROUP.—Prior to 1800, a number of authors had described species now included in the Diaperini. One needs only to study the synonymy involved in a well-known species, such as the European Diaperis boleti (Linnaeus), to appreciate how confusing these insects were to the early taxonomists. This species was origi- nally described in 1758 as Chrysomela Boleti Linnaeus. Earlier it had been mentioned as a Dermestes without a specific name (Udd- mann, 1753). In succeeding years it was placed in Tenebrio (DeGeer, 1775) and Coccinella (fasciata) Scopoli (1763).^ 2 Synonymy based on Seidlitz (1894, p. 515). DIAPERINI NORTH OF MEXICO—TRIPLEHORN 351 It remained for MuUer (1776, p. 74) to validate the generic name Diaperis of GeofFroy by including under it boleti Linnaeus. The his- tory of the group might perhaps be regarded as beginning at this point. Other species have had a similar history. Among the North Amer- ican species, Neomida bicornis (Fabricius) was originally described (1776) m the genus Hispa; Platydema ellipticum (Fabricius) was placed originally in the genus Tenebrio and later transferred to Mycetophagus (Fabricius, 1801). Platydema jiavipes (Fabricius, 1801) was also placed in Mycetophagus. By 1831, the genus Diaperis had become quite sizable. It was in that year that Laporte and Brulle produced their monumental taxo- nomic treatise on the world Diaperini entitled "Monographic du Genre Diaperis." In this key work, the authors divided the genus Diaperis in its older sense into seven component genera, recognizing and de- scribing as new, Platydema and Oplocephala {=Hoplocephala=Neo- mida), both of which are represented in North America, and Ceropria of the old world tropics, along with Diaperis in its present sense. Three other genera which they originally included have been moved to other widely separated tribes. Redtenbacher (1845, p. 128) was the first to assign a name to this assemblage of genera recognized by Laporte and BruUe. His "Familie Diaperides" contained five genera: Pentaphyllus, Phyletes (=Alphi- tophagus), Platydema, Diaperis, and Oplocephala (=Neomida). The next important contribution was that of Mulsant (1854). He divided the European Latigenes (=Tenebrionidae) into five "Groupes" which more or less correspond to currently recognized subfamilies. His third "Groupe" he caUed "Les Diaperides," and this was divided into seven "Families," among which are a niunber of units which we now recognize as tribes (e.g., Phaleriens, Ulomiens), Mulsant's third "Famille" was called "Les Diaperiens" and is roughly comparable to the tribe Diaperini in its present sense. On the basis of the entire anterior margin of the eyes, he separated the "Penta- phj'Uaires," containing only the genus Pentaphyllus from the remain- der of the "Famille," which he called "Les Diaperaires." In this "Deuxieme Branche" he recognized the following genera: Scaphidema, Philethus (= Alphitophagus) , Diaperis, Platydema, and Oplocephala {= Neomida). It is to the everlasting credit of Mulsant that his concept of the group, proposed at this early date, still stands rela- tively unchanged. His six genera (including Pentaphyllus) are identi- cal, except for nomenclatorial changes, with the six listed by Portevin in 1934 for France. Redtenbacher (1858) divided the Tenebrionidae, as currently understood, into four families of which number 47 is the "Diape- rides." In this family he placed 14 genera, including all of the genera 352 PROCEEDINGS OF THE NATIONAL MUSEUM ^pol. 117 which comprise the Diaperini in its present sense, plus such extra- neous elements as Cossyphus, Oochrotus, Ammobius, Bolitophagus, Erelus, Trachyscelis, Sphindus, and, interestingly enough, Phaleria. The genera now included in the Ulomini were placed in another family ("Tenebrionides"). Lacordaire (1859), treating the group on a worldwide basis, divided the "Tenebrionides" into 46 tribes of which number 29 is called "Diaperides." He followed Mulsant closely, retaining the distinction between the "PentaphyUides" (genus Pentaphyllus) and the "Dia- perides vraies," which included all the genera Mulsant recognized plus several tropical genera which need not concern us here {Cos- monota, Ceropria, Hemicera). This work contains no great inno- vation over that of Mulsant. Jacquelin du Val (1861) divided the 'Tamille des Tenebrionides" into 23 "Groupes." His "Groupe 18, Diaperites" embraced the "Bohtophagites, Ulomites, Gnathoc^rites and Hypophloeites" or, in other words, the Ulomini and Bolitophagini of modern workers, as well as "Diaperites propres." In the diaperines at least, he seems to have been a lumper of higher categories but a splitter at the generic level. His lack of conservatism influenced later workers to include a number of extraneous elements which ultimately made the Diaperini a catch-all for a number of genera which were diflacult to place. By the time of Reitter (1911a), the group was again on a relatively firm taxonomic foundation. He divided the Tenebrionidae into 12 tribes, the Diaperini containmg Scaphidema, Diaperis, Platydema, Arrhenoplita {=Neom,ida), Alpkitophagus, and Pentaphyllus. Around the middle of the 19th century, as the earher North Amer- ican coleopterists began to give serious attention to the Tenebrionidae, they needed only to fit their new finds into an already well-con- structed classification. No sweeping changes have been introduced by any of the American workers who confined their activities in the group to descriptions of new genera and species. The tribe Diaperini as treated by LeConte and Horn (1883) consisted of eight genera divided into three groups. The first group (Diaperes) contained Diaperis, Hoplocephala (=Neomida), Platydema, Phylethus (=Alphi- tophagus), Liodema, and Scaphidema; the second group (Hypophloei) contained Hypophloeus; the third group (Pentaphylli) contained Pentaphyllus. As is frequently the case, the greater number of North American species of Diaperini were described by Em"opean workers. Prominent among these were Laporte and Brulle (1831). Through correspond- ence with A. Villiers of the Musee