A revision of the genus Rudolfina Roháček (Sphaeroceridae: Limosininae)

The genus Rudolfina Roháček, 1987 is revised and redefined with the description of the following nine new species, all from the New World: R. bucki sp. nov. (Mexico), R. exuberata sp. nov. (widespread, from USA to Brazil), R. howdeni sp. nov. (Mexico), R. megepandria sp. nov. (Mexico), R. newtoni  sp. nov. (Mexico), R. pauca  sp. nov. (Guatemala, Mexico), R.  pilosa  sp. nov. (Mexico), R. remiforma sp. nov. (Mexico) and R. tumida sp. nov. (Mexico, USA). Rudolfina is compared to closely related genera in the Archiceroptera genus complex, which in turn is recognized as part of a large, mostly Neotropical clade including Robustagramma Marshall & Cui, 2005, Pterogramma Spuler, 1924, Aptilotella Duda, 1924, Bitheca Marshall, 1987, Bromeloecia Spuler, 1924 and Archiceroptera Papp, 1977.


Introduction
The genus Rudolfina Roháček, 1987 was introduced as a new name for the pre-occupied Rudolfia Roháček, 1982, which was originally described for a single Palaearctic species, Limosina rozkosnyi . Three species have since been described: R. digitata Marshall, 1991 andR. cavernicola Marshall &Fitzgerald, 1997 from North America (Marshall 1991;Marshall & Fitzgerald 1997) and R. zhangi Su, 2017 from China (Su et al. 2017). Marshall (1982) also recognized several undescribed species of Rudolfina s. str. from Mexico, but deferred publishing descriptions of those species until adequate material was available to properly treat the Neotropical fauna and to determine the limits between Rudolfina and superficially similar Neotropical species in the Archiceroptera genus complex.   Table 1. Character states used in the phylogenetic analysis of Rudolfina Roháček, 1987. 10. Epandrium -prominence: (0) regular, equal in width to tergite 5; (1) swollen, wider than tergite 5.
16. Cercus -distal seta: (0)  European Journal of Taxonomy 593: 1-48 (2020) Results aBdomen. Sternites and tergites well sclerotized and setose (posterior and lateral margins more densely setose). Male sternite 4 usually simple (rarely densely setose medially). maLe aBdomen. Posterior margin of sternite 5 with lobe on each side of medial emargination (shape and size of emargination and lobes vary among species). Transverse (ventral) portion of sternite 6 narrow; straight or weakly arcuate. Ring sclerite (in the right membrane of segment 7, possibly derived from a spiracle) large and distinct. Epandrium setose, often with larger setae lateral to anal opening, and with right anteroventral corner drawn out into a finger-like process that extends to the hypandrium. Male cercus usually distinct, fused with the epandrium (reduced and obscured beneath the epandrium in a few species; e.g., R. pilosa sp. nov., R. remiforma sp. nov.). Hypandrium (Fig. 3B) Y-shaped with emarginate posteromedial extension; hypandrial arms posteriorly deeply bilobed posteriorly, with lateral lobe articulating with the epandrium and the medial lobe articulating with posterolateral corner of hypandrium. Pregonite distinct, small, near anterior base of postgonite. Postgonite generally simple and slender, with 3-4 setulae on anterior margin but modified in some species; ejaculatory apodeme small and finger-like, with small globular sperm pump, usually close to the basiphallus (easily lost during dissection); basiphallus simple (without an epiphallus); distiphallus with distinct elongate dorsal sclerite; acrophallus with dorsolateral lobes and a single ventral sac (often reduced).
FemaLe aBdomen. Tergite 8 apparently tripartite, with two lateral triangular sclerites and a medial sclerite (reduced in several species). Epiproct bare except for usual pair of small setae and a few scattered setulae, strongly sclerotized, and fused laterally with cerci (except in R. cavernicola). Cercus with single flattened apical seta. Sternite 7 variable. Sternite 8 weak, transverse, covered in small setulae; pair of small, bispinose plates along posterior margin. Hypoproct very narrow, forming horseshoe-shaped band immediately below the cerci. Spermathecae (1 pair + 1 single) generally disc-shaped or lenticular, with thin, long sclerotized ducts.

Related and similar genera
All species of Rudolfina will key out to "Rudolfia" in the key to Nearctic Sphaeroceridae by Marshall & Richards (1987) but they will key out as "Archiceroptera genus complex, in part" at couplet 72 in the key of Marshall & Buck (2010) to Neotropical Sphaeroceridae. This previous treatment reflected uncertainty about the limits between Rudolfina and the many undescribed Neotropical species in the Archiceroptera genus complex. The Archiceroptera complex is part of a larger group of Limosininae (including Aptilotella Duda, 1924, Archiceroptera Papp, 1977, Bitheca Marshall, 1987, Bromeoloecia Spuler, 1924, Pterogramma Spuler, 1924and Robustagramma Marshall & Cui, 2005 characterized by an unusual process extending medially from the lower right margin of the epandrium to the hypandrium. The relationships within this group need further study but the morphological analysis by Paiero (2017) suggests that Rudolfina is closely related to Bromeloecia. Within this group, Rudolfina resembles Archiceroptera in characters of the female epiproct and cercus. However, in Archiceroptera the epiproct is completely desclerotized medially (anteriorly sclerotized in Rudolfina), the cercus is separate from the epiproct and has a partially concave inner margin, and sternite 8 is divided into a pair of elongate lateral sclerites without the paired setulose sclerites found in Rudolfina. Archiceroptera species also differ from Rudolfina in having M 1 extending as a pseudovein to the wing margin, CuA 1 rarely with a distinct stub vein, the male cercus free from the epandrium and with a distinct ventral process, and (in many, but not all species) five or more dorsal mid tibial setae and two or more inclinate orbital setulae.

Biology
Roháček (1987) recorded R. rozkosnyi from dung and occasionally from mud and decaying vegetation, but most of the new species considered here were collected in dung or carrion traps. Larvae remain unknown.

Distribution
Rudolfina has a mostly western Nearctic montane distribution, with high endemism in the southwest and the mountains of Mexico (Sierra Madre del Sur, Sierra Madre Oriental and Sierra Madre de Chiapas). Two widely separated species occur in the Palaearctic region (R. rozkosnyi and R. zhangi) and one species (R. exuberata sp. nov.) is widespread at low elevations from the southern United States to South America. Other than R. exuberata sp. nov., no true species of Rudolfina are known from south of Guatemala. Other Neotropical species previously treated as Rudolfina are discussed below.

Results of the phylogenetic analysis
Twenty-seven most parsimonious trees were generated, summarized here as a strict consensus tree (Fig. 5) and a majority rules consensus tree (Fig. 6). Characters were optimized on one of the equal length trees (Fig. 7) which was selected based on the recovery of several groups supported by putatively higher weight characters. Shared male genitalic morphology supported a close relationship of Rudolfina bucki sp nov. with R. megepandria sp. nov. and R. tumida sp. nov. with [R. rozkosnyi + R. digitata + R. zhangi]. The combined elongation of the epiproct and female cercus suggests that R. newtoni sp. nov. is closely related to [R. exuberata sp. nov. + R. pauca sp. nov. + R. remiforma sp. nov.], although the form of the epiproct in R. newtoni sp. nov. is apparently intermediate between the strongly elongated form found in the R. exuberata clade and the shorter epiproct of other Rudolfina. All trees recovered R. cavernicola as a sister taxon to the remaining species, which form a monophyletic group characterized by the fusion of the female cercus with the posterolateral corner of the epiproct, the elongation of the medial part of tergite 8 and by characters of the male cercus and surstylus. This tree suggests a New World origin for Rudolfina.
Within Rudolfina excluding R. cavernicola, R. rozkosnyi, R. digitata and R. tumida sp. nov. appear to be a basal grade predating the origin of a clade comprising the Mexican-Guatemalan species. These four species all have a laminate lobe on the surstylus, apparently derived from the simple laminate margin of R. cavernicola (absent in other species). The largely Mexican-Guatemalan clade can be recognized by the simple, rounded anterior lobe of the male surstylus and the absence of dorsal swellings on the dorsal sclerite of the distiphallus. The R. exuberata group (including R. exuberata sp. nov., R. remiforma sp. nov. and R. pauca sp. nov.) is characterized by a small elongate male cercus, tulip-shaped epiproct, and reduction of the female cercus. Rudolfina remiforma sp. nov. and R. pauca sp. nov. are known from only a few localities at higher elevations, as is typical of the genus, but the widespread R. exuberata sp. nov. occurs at much lower elevations than its more localized congeners. European Journal of Taxonomy 593: 1-48 (2020)

Key to the New World Rudolfina
Accurate identification of species of Rudolfina is largely dependent on examination of male sternite 5 and genitalic characters of both sexes; dissection may be required. Females of R. tumida sp. nov., R. bucki sp. nov., R. pilosa sp. nov. and R. zhangi are unknown.  Roháček, 1987. Characters and character states refer to those given in Table 1 6. Sternite 5 with small medial triangular lobe (Marshall & Fitzgerald 1997: fig. 5). Surstylus strap-like, with base ~1.5 × as wide as distal margin; anterior margin weakly lamellate (Marshall & Fitzgerald 1997: fig. 2

Female
Unknown.

Remarks
The male abdomen is similar to that of R. megepandria sp. nov., but males can be separated from that species by the shorter cercus and less pronounced epandrium. Marshall & Fitzgerald, 1997 Fig. 21A

Material examined
The original type series from Kremmer's Cave was re-examined along with the following material.

Remarks
This species is newly recorded from Mexico. The illustration of this species that accompanied the original description (Marshall & Fitzgerald 1997: fig. 1) includes what appears to be a large seta coming off the anterior base of the surstylus; this is an unsocketed laminate lobe. Marshall, 1991 Fig. 21A

Material examined
In addition to the original type material, the following material was examined: CANADA  Marshall (1991).

Remarks
Rudolfina digitata, the second species to be described in this originally Palaearctic genus, is widely distributed in western North America and also occurs in a few eastern North American sites, including Mount Washington, New Hampshire. Mount Washington is known to have other species with disjunct western Cordilleran and eastern Appalachian distributions (e.g., Oeneis melissa (Fabricius, 1775) European Journal of Taxonomy 593: 1-48 (2020) (Lepidoptera: Nymphalidae)), and the apparently disjunct population of R. digitata there suggests it may have once had a more extensive range. The other New Hampshire locality is also one of two known localities for the rare monotypic sphaerocerid genus Volumosina Roháček & Marshall, 2017, otherwise known from one old growth forest in Ontario.
The male abdomen is most similar that of the Palaearctic R. zhangi.

Etymology
The specific name, which has been a manuscript name since Marshall (1982), is from the Latin for 'abundant': of the 1933 specimens examined for this study, 1649 were R. exuberata sp. nov.      maLe aBdomen (Fig. 11). Posterior margin of sternite 5 with pair of large medially-projecting blunt teeth on each side of emargination; emargination extending ~¼ length and ~1/8 width of sternite 5; emargination lined with sclerotized strip. Transverse part of sternite 6 weakly arcuate. Epandrium with pair of long lateral setae, 3-4 smaller pairs of setae along lower margin of anal opening and several other small setae scattered over the surface; subanal plate narrow but complete. Surstylus (in lateral view) with small hirsute anterior lobe and elongate clavate posterior lobe (~4.0 × length of anterior lobe); posterior lobe with 4-5 large setae and numerous smaller setae apically, and 2-3 bifurcating setae on inner surface. Cercus elongate, clavate, projecting ventrally. Postgonite elongate, narrowly rounded apically. Dorsal sclerite of distiphallus (Fig. 11F-H) not swollen along length and not extending beyond apex of acrophallus.

Etymology
The specific name, which has been a manuscript name since Marshall (1982), refers to the unusually large epandrium.

Remarks
Rudolfina megepandria sp. nov. is diagnosed by its swollen male epandrium and distinctively shaped sternite 5. It is most closely related to R. bucki sp. nov., which has a less pronounced epandrium and differs in details of the surstylus and cercus.

Remarks
This species is distinguished from other Rudolfina by characters of the surstylus and male sternite 5. The female epiproct is intermediate in shape between the strongly modified epiproct found in the R. exuberata group and the unmodified epiproct of other Rudolfina.

Etymology
The species name is the Latin for 'few'. Compared to the closely related R. exuberata sp. nov., which occurs throughout the Neotropical region and has been collected at over a hundred different sites, R. pauca sp. nov. has been infrequently collected and remains known from only five sites in Mexico and Guatemala.

Remarks
See comments under R. exuberata sp. nov.

Female
Unknown.

Remarks
This species is most similar to R. newtoni sp. nov., which also has a setulose male sternite 4 and sternite 5. These species are easily distinguished by the shape of the male surstylus.
FemaLe aBdomen (Fig. 20). Tergite 7 with posterior margin entire. Medial part of tergite 8 poorly sclerotized or fused with epiproct. Epiproct tulip-shaped, with length of anterior narrowed portion equal or subequal to that of posterior portion. Cercus small, as long as or only slightly longer than flattened apical seta; fused anterolaterally to epiproct. Sternite 7 with posterior margin broadly rounded. Spermathecae lenticular, inner surface with conical projection connecting with duct; paired spermathecae each with duct ~2.0 × length of spermatheca before common duct; single spermathecal duct similar in length. European Journal of Taxonomy 593: 1-48 (2020) weakly arcuate. Epandrium swollen, wider than preceding portion of abdomen (denuded on holotype); subanal plate incomplete. Posterior lobe of surstylus elongate, with apex and posterior margin heavily setose; anterobasal lobe broadly rounded and laminate, with distal triangular projection. Cercus ovoid. Postgonite elongate with apex acute. Dorsal sclerite of distiphallus ( Fig. 21B-C) with several small swellings along length and extending beyond apex of acrophallus.

Fig. 21. Distribution of species of New World Rudolfina
European Journal of Taxonomy 593: 1-48 (2020) Remarks Rudolfina tumida sp. nov. is distinctive for the uniquely swollen epandrium and large surstylus.

Remarks
Leptocera (Acuminiseta) prominens was provisionally treated as Rudolfina by Roháček et al. (2001), who noted that Acuminiseta Duda, 1925 does not occur in the New World. This species does not fit into Rudolfina as defined here, but belongs elsewhere in the Archiceroptera complex and will be treated in a later paper.

Discussion
With the exception of the widespread lowland species R. exuberata sp. nov., Rudolfina is a Holarctic, and largely Nearctic, genus with highest diversity in the highlands of Mexico. The few records from mountains in Mexico and Guatemala are from an area recognized as a transitional zone between the Nearctic and Neotropical regions, which has been referred to as the Mexican Transition Zone by some authors (e.g., Morrone 2014). The pattern of diversity in Rudolfina is consistent with those observed in some bats (Ortega & Arita 1998), copepods (Aglaodiaptomus Light, 1938and Skistodiaptomus Light, 1939see Suarez-Morales et al. 2005), passalids (Gutierrez-Velazquez et al. 2013) and weevils (García-Navarrete & Morrone 2018). There are no records of Rudolfina species other than R. exuberata sp. nov. from lowland Guatemala, or any other Neotropical locality. We have studied tens of thousands of specimens collected from throughout Costa Rica over the past thirty years without finding any specimens other than R. exuberata sp. nov. that fit Rudolfina as currently defined; this reinforces our conclusion that the distribution of Rudolfina is effectively bounded southward by the limits of the Nearctic region. The origins of Rudolfina are likely to be in western North America, where R. cavernicola, the basalmost species, occurs, with the Nearctic and Palaearctic faunas diverging relatively early in Rudolfina's evolutionary history.
Sequence data for the 'barcode' region of cytochrome oxidase I was considered and supported species concepts consistent with the results presented here on the basis of morphology (Paiero 2017), but COI data was available for only three species (R. digitata, R. rozkosnyi and R. exuberata sp. nov.). Other specimens of Rudolfina available at this time were mostly collected in pan traps and were not preserved adequately for genetic study. The number of new species in the University of Guelph insect collection and the apparent novelty of the limited material from other collections suggest that many further new species await discovery. Southern Mexico is especially poorly represented in the current material. We have only a single specimen (R. cavernicola) from the Sierra Madre Occidental range and we have seen no Rudolfina from the Sierra Madre Oriental. Further collecting efforts in Mexico are therefore likely to greatly improve our understanding of Rudolfina.