A new species of the genus Sulawesifulvius, S. thailandicus Wolski, Yasunaga & Gorczyca, sp. n., is described from Thailand. The present finding also represents the first distribution record in Indochina for the genus. Color adult habitus images for S. thailandicus and S. schuhi (type species of the genus), male genital drawings of S. thailandicus, and scanning electron micrographs of selected structures of S. schuhi and S. thailandicus are provided.

Miridae , Cylapinae , Sulawesifulvius , description, diagnosis, Oriental Region

Sulawesifulvius Gorczyca, Chérot & Štys, 2004 is a unique cylapine genus established by Gorczyca et al. (2004) to accommodate a single species, S. schuhi Gorczyca, Chérot & Štys, 2004, described from Sulawesi, Indonesia. Recently, Mu and Liu (2014) added the new species S. yinggelingensis Mu & Liu from Hainan (China) and Yeshwanth and Chérot (2015) described a new species, S. indicus Yeshwanth & Chérot, from India, which significantly expanded the distribution range of Sulawesifulvius from the Wallacea to the Oriental Region (Fig. 22).

In this paper, a new species, S. thailandicus, is diagnosed and described based on material recently collected in central Thailand. Habitus photographic images of Sulawesifulvius schuhi (type species of the genus) and S. thailandicus sp. n., male genitalic drawings of S. thailandicus sp. n., and scanning electron micrographs of the selected structures of S. schuhi and S. thailandicus are provided. The present discovery of a new species in Thailand also represents the first distributional record from Indochina for the genus.

Observations were made using an Olympus SZX12 stereomicroscope and an Olympus BX50 optical microscope. Digital images of live individuals were taken by TY with Canon EOS Kiss digital camera body + Olympus OM-System. Scanning electron micrographs were taken using Hitachi S-3400N and Phenom XL Scanning Electron Microscopes. Measurements were taken using an eyepiece (ocular) micrometer; all measurements are given in millimeters.

Dissections of male genitalia were performed using the technique mentioned by Kerzhner and Konstantinov (1999). The terminology of the male genitalic structures follows Konstantinov (2003) for the elements of the genital capsule and parameres and Cassis (2008) in using the term “endosoma” for the male intromittent organ. The study was based on the material deposited in the Insect Collection, Entomology & Zoology Group, Plant Protection Research and Development Office, Department of Agriculture, Bangkok (DOA), T. Yasunaga Collection, Nagasaki, Japan (TYCN); and Department of Zoology, University of Silesia, Poland (US).

Gorczyca et al. (2004) included Sulawesifulvius in the subfamily Cylapinae, based on the presence of the two-segmented tarsus and the claw with a subapical tooth (Fig. 10). The placement of Sulawesifulvius in the tribe FulviinisensuGorczyca (2000, 2006) was based on its horizontally elongated head and short antenna (Figs 1–7, 18–19, 22–24). Our examination revealed that Sulawesifulvius possesses the subdivided labial segment I which is shared by most genera currently placed in Fulviini (Wolski and Henry 2012, 2015; Wolski 2013; Wolski and Gorczyca 2014) but is not present in other tribes of Cylapinae, except for such rhinomirines as Rhinomiris Kirkaldy (Wolski and Henry 2015), Lundbladiola Carvalho, Pararhinomiris Gorczyca, Rhinomiridius Poppius, and Rhinomiriella Gorczyca (Wolski, pers. obs.). Other characters that warrants a placement of Sulawesifulvius within the tribe Fulviini include among others: 1) the dorsal surface with ornamentation composed of dense, tiny tubercles (Figs 7–8; 19–21); 2) the labial segment II subdivided subapically; 3) eyes with dense interocular setae (Figs 7, 19); 4) the metathoracic gland evaporative area narrowly developed, restricted to ventral margin of metepisternum; 5) the two segmented tarsus (Fig. 10); 6) the genital capsule with the dorsal wall long, only weakly shorter than ventral wall, genital opening terminal in orientation (Fig. 12; Gorczyca et al. 2004: fig. 6; Mu and Liu 2014: fig. 5; Yeshwanth and Chérot 2015: fig. 1).

Similar, shagreened surface of the dorsum to that found in Sulawesifulvius is present in many genera of Fulviini (Gorczyca and Wolski 2007: fig. 9; Wolski and Henry 2012: Figs 27–32, 54, 58, 60–61, 73–74; Pluot-Sigwalt and Chérot 2013: Figs 2A–B; Wolski and Gorczyca 2014: fig. 29–31) and is not found in other tribes of Cylapinae except for some rhinomirines (Wolski, pers. obs.).

The subdivision of the labial segment II in the Fulviini was noted among others by van Doesburg (1985: fig. 5) and Namyatova et al. (2016: fig. 10A). This character was also noted for Psallops Usinger and was not found in the representatives of the remaining cylapine tribes (Namyatova et al. 2016).

In Sulawesifulvius the dorsal wall of the genital capsule is long, weakly shorter than ventral wall and the genital opening is terminal in orientation (Fig. 12). Similar shape of the genital capsule was noted for the fulviine genera Peritropis (Moulds and Cassis 2006: fig. 1H; Yeshwanth et al. 2016: Figs 34, 39, 45, 52, 57, 62), Mimofulviella Wolski (Wolski 2008), Euchilofulvius Poppius (Yeshwanth et al. 2016: fig. 10) and Fulvius Stål (Yeshwanth et al. 2016: Figs 16, 21, 34, 39) and is very common among other fulviine genera (Wolski, pers. obs.). In other cylapine tribes the dorsal wall of the genital capsule is shorter than the ventral wall and the genital opening is directed more upwards (Yasunaga 2000: fig. 5; Cassis et al. 2003: Figs 1H, 2E; Cassis and Monteith 2006: fig. 3A; Wolski 2010: Figs 6A, 15A; Wolski and Gorczyca 2012: Figs 79, 83; Yeshwanth et al. 2016: Figs 2, 76).

Sulawesifulvius was diagnosed by Gorczyca et al. (2004), Mu and Liu (2014), and Yeshwanth et al. (2016). The most distinctive characters of Sulawesifulvius, not shared by any other known fulviines, include the antennal segment III longest (Figs 1–3), the cuneus long, curved, nearly enveloping membrane (Figs 1–3, 5, 18, 22, 25), and the enlarged metafemur with subapical depressions laterally (Gorczyca et al. 2004: fig. 2). An additional character that could clearly distinguish Sulawesifulvius from other Fulviini is the characteristic marking on the hemelytron composed of blackish, longitudinal, curved patches occupying apical half of the exocorium, bordering R+M vein and inner half of the basal margin of the cuneus (Figs 1, 2 (arrows); Mu and Liu 2014: 1–2; Yeshwanth and Chérot 2015: Figs 8–9). The shape of the parameres in Sulawesifulvius species (except for S. indicus) is bizarre, not exhibited by any other fulviine (Figs 14–17; Gorczyca et al. 2004: 6–9, Mu and Liu 2014: 7–10). By the oval body (Figs 1–3, 5, 18, 22) and the short pronotum with elevated lateral margins and anterior angle protruding onto eyes (Figs 1–5, 7, 18–19, 22) Sulawesifulvius is most similar to the genus Peritropis Uhler, from which it can be easily distinguished by the characters mentioned above.

We thank Taksin Archawakom (director of SERS: Sakaerat Environmental Research Station, Nakhon Ratchasima, Thailand) and Kazutaka Yamada (Tokushima Prefectural Museum, Tokushima, Japan) who kindly supported our field investigations. We also are grateful to Magdalena Kowalewska-Groszkowska (Museum and Institute of Zoology, Polish Academy of Science, Warsaw, Poland) and Jolanta Brożek (US) for their kind assistance in taking SEM microphotographs. Frédéric Chérot (Service Public de Wallonie, Gembloux, Belgium) and Anna A. Namyatova (University of New South Wales, Sydney, Australia) kindly reviewed the manuscript.