73 (3): 457 – 475 23.12.2015 © Senckenberg Gesellschaft für Naturforschung, 2015. From “insect soup” to biodiversity discovery: taxonomic revision of Peloridinannus Wygodzinsky, 1951 (Hemiptera: Schizopteridae), with description of six new species Christiane Weirauch * & Sarah Frankenberg Department of Entomology, University of California, Riverside, 900 University Avenue, 92521 Riverside, CA, USA; Christiane Weirauch [[email protected]]; Sarah Frankenberg [[email protected]] — * Correspond ing author Accepted 05.x.2015. Published online at www.senckenberg.de/arthropod-systematics on 14.xii.2015. Editor in charge: Christian Schmidt. Abstract With only about 320 described species, Dipsocoromorpha is currently one of the smallest and least studied infraorders of Heteroptera (He- miptera). Specimens are small (often 1 – 2 mm), live in cryptic habitats, are collected using specialized techniques, and curated material in natural history collections is scarce. Despite estimates of vast numbers of yet to be described species, species discovery and documentation has slowed compared to peak taxonomic activity in the mid-20th century. We show, using the genus Peloridinannus Wygodzinsky, 1951 (Hemiptera: Schizopteridae) as an example, that curating specimens from bulk samples already housed in natural history collections is an effective way of advancing our understanding of the biodiversity of this charismatic group of true bugs. Peloridinannus Wygodzinsky was described as a monotypic genus, known only from two female specimens from Costa Rica. Based on examination of 59 specimens from Costa Rica, Panama, Ecuador, and Peru, six new species of Peloridinannus are described, Peloridinannus curly sp.n., Peloridinannus larry sp.n., Peloridinannus laxicosta sp.n., Peloridinannus moe sp.n., Peloridinannus sinefenestra sp.n., and Peloridinannus stenomargaritatus sp.n. Further, males are documented for the first time for this genus. The holotype and paratype of Peloridinannus margaritatus Wygodz- insky are shown to belong to different species, and the paratype is transferred to Peloridinannus stenomargaritatus sp.n. Male and female genitalic characters, as well as wing venation and wing structure characters are documented using digital images including scanning and confocal micrographs. This taxonomic revision and morphological documentation will also provide a foundation for any future investiga- tions into the enigmatic taxonomic position of Peloridinannus within the Schizopteridae. Key words Heteroptera, Dipsocoromorpha, Neotropical region, species discovery, taxonomic revision, morphology. 1. Introduction At first glance Schizopteridae (Hemiptera: Dipsocoro- comprise a sclerotized corium and a flexible membrane, morpha) are reminiscent of “little brown beetles”: the are transformed into completely sclerotized and strong- ~ 250 worldwide described species are typically between ly curved elytra, giving the specimens a “coleopteroid” 1 and 2 mm small and feature various shades of brown appearance (WYGODZINSKY 1948; EMSLEY 1969; HILL (EMSLEY 1969; SCHUH & SLATER 1995; WEIRAUCH & ŠTYS 2013). Despite their small size that requires specialized 2014). In addition, females in numerous species possess curation and morphological documentation techniques, elytra where the hemelytra, that in Hemiptera typically Schi zo pteridae feature stunning and still largely undocu- ISSN 1863-7221 (print) | eISSN 1864-8312 (online) 457 Weirauch & Frankenberg: Taxonomic revision of Peloridinannus Wygodzinsky mented morphological diversity, ranging from complex As part of a US National Science Foundation “Ad- male genitalia involving modifications of the pre-genital vancing Revisionary Taxonomy and Systematics” (ARTS) abdomen (WYGODZINSKY 1950) to a variety of unique program grant, the Heteropteran Systematics Lab at the structures on the head and thorax (Corixidea group of University of California, Riverside has been focusing on genera; unpublished data) including the hemelytron (e.g., biodiversity documentation of Schizopteridae and other “wing organs” in Chinannus Wygodzinsky, 1948 [WY- Dipsocoromorpha. The project team to date has retrieved GODZINSKY 1948]). Schizopteridae live in cryptic micro- and sorted to morphospecies more than 18,000 specimens habitats, such as leaf litter and top soil (EMSLEY 1969), of Dipsocoromorpha from residue samples, over 6,000 of with greatest diversity in the wet tropics. The majority which have been identified as Schizopteridae, discover- of known specimens were collected using specialized ing unexpected genus-level diversity and overwhelm- passive collecting techniques rarely employed by hemi- ing numbers of undescribed species. As an example, the pterists, including leaf litter extraction, yellow pan traps, genus Chinannus that contained two species from Costa and Malaise traps. It is therefore not surprising that the Rica and Trinidad (WYGODZINSKY 1948) is now docu- biodiversity of Schizopteridae is poorly documented at mented across the Neotropical region and the number of the species level. described species is about to increase to 28 (A. Knyshov Species discovery in the 21st century often involves et al. unpublished). That taxonomic revision is based on travels to highly endemic areas and remote places. While about 400 specimens, which is a substantial amount of this is an important avenue for the discovery of new taxa, material for Schizopteridae that are typically collected in we argue that species discovery for certain groups of small numbers. During the present project, we examined invertebrates can be accelerated by focusing on already a total of 59 Peloridinannus specimens, 52 of which were existing resources such as bulk or residue samples. These retrieved from residue samples housed at the FMNH. Rel- are samples that were collected often many decades ago ative to the sample size, the number of undescribed spe- using passive trapping techniques including litter extrac- cies discovered amongst these specimens is astonishing. tion, and sorted for certain target taxa. These collections Here, we taxonomically revise the genus Peloridi- provide a virtually untapped biodiversity resource stored nannus, describe six new species, and for the first time in natural history collections around the globe. The bulk document males of the genus. The taxonomy of Schizo- sample collection at the Field Museum of Natural His- pteridae relies heavily on genus- and species-level char- tory (FMNH) http://www.fieldmuseum.org/node/5031 is acters derived from the male genitalia, and therefore the one example. Schizopteridae are small and easily over- discovery of males for this genus is crucial. The known looked, and few systematists focus on this group. Many distribution for species of Peloridinannus now ranges undescribed species are therefore waiting to be discov- from Central America to Southeastern Peru. Peloridi- ered in jars of “insect soup”, i.e. the residues of trap sam- nannus is currently not placed in any of the three sub- ples. families of Schizopteridae, in part resulting from the fact Peloridinannus Wygodzinsky was described as that the genus combines characters that EMSLEY (1969) a monotypic genus based on the female holotype of treated as diagnostic for Hypselosomatinae, Schizopte- Peloridinannus margaritatus Wygodzinsky, 1951 from rinae and Ogeriinae. Clarifying the phylogenetic posi- Costa Rica (WYGODZINSKY 1951). A second, syntopic tion of Peloridinannus is beyond the scope of this paper. (i.e. reported from the same locality and collection Nevertheless, the digital images, scanning electron and event) female specimen was thought to be conspecific confocal micrographs, and line drawings included pro- and designated as the paratype in the same publication. vide the first thorough documentation of morphological Peloridinannus stands out amongst other Schizopteridae characters for this striking genus and will be critical for by distinct wing venation with numerous cells that, in future phylogenetic analyses of morphological characters most species, feature small depressions known as “are- across Schizopteridae. oles” resulting in a superficial resemblance to moss bugs in the family Peloridiidae (Hemiptera: Coleorrhyncha). Other noteworthy features of Peloridinannus mentioned by WYGODZINSKY (1951) are the relatively large size, 2. Material and methods prominent eyes, and a relatively well-developed ovi- positor. The two known specimens were collected from a mid-elevation site in the province of Cartago and are 2.1. Material deposited as slide mounts in the American Museum of Natural History (AMNH). Unfortunately, the collecting Three point-mounted specimens of Peloridinannus spp. method was not recorded on the labels and the paratype and the slide-mounted P. margaritatus holotype and is in poor condition. Other than some brief comments on paratype were loaned from the AMNH and INBio. Two the morphology of this taxon by EMSLEY (1969), who had specimens were hand-collected by one of us (CW) during not examined specimens of Peloridinannus himself, the field work in Southeastern Peru. The majority of speci- genus has not been referred to in the literature since its mens (52) were discovered while sorting ethanol-pre- description and no additional specimens have come to served bulk samples of Dipsocoromorpha at the FMNH. light. As part of the ARTS Dipsocoromorpha project, other dry 458 ARTHROPOD SYSTEMATICS & PHYLOGENY — 73 (3) 2015 (e.g., United States National Museum, Natural History Confocal imaging (Fig.