Research Article |
Corresponding author: Péter Kóbor ( kobor.peter@atk.hu ) Academic editor: Dávid Rédei
© 2022 Péter Kóbor.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kóbor P (2022) A redefinition of Umbrageocoris with new species and new combinations (Heteroptera, Lygaeoidea, Geocoridae). Deutsche Entomologische Zeitschrift 69(2): 139-150. https://doi.org/10.3897/dez.69.85584
|
The geocorine (Hemiptera: Heteroptera: Lygaeoidea: Geocoridae) true bug genus Umbrageocoris Kóbor, 2019 is redefined based on new morphological information from newly acquired specimens. Two new species are described: U. boonei sp. nov. from continental Indomalaya and U. malipatili sp. nov. from Australia; two new combinations are proposed: U. elegantulus (Distant, 1904), comb. nov., and U. woodwardi (Malipatil, 1994), comb. nov. (both transferred from Geocoris Fallén, 1814). Keys, diagnoses, and distribution data to the discussed species are provided. Hypotheses on the origin of Umbrageocoris and its relationship to other geocorine genera in the region are formulated. New country records: U. elegantulus (Papua New Guinea), U. maai maai (Thailand, Laos) and U. woodwardi (Papua New Guinea).
big-eyed bugs, Geocorinae, Hemiptera, key, new placement, species description
Geocoridae, commonly known as big-eyed bugs, are a moderately species-rich lygaeoid family exhibiting highly specialized morphology, yet their taxonomy and systematics are poorly understood (
The recently described Umbrageocoris Kóbor, 2019 currently comprises two species, one of them with two subspecies (
Specimens were borrowed from Bernice P. Bishop Museum, Honolulu, USA (
Label data are cited verbatim. Lines on labels are separated with ‘/’; contents of different labels are separated with ‘//’; remarks are given in square brackets ‘ []’.
Exoskeletal and genital structures were studied with Kern Optics OZL 466 stereoscopic and Keyence VHX 5000 digital microscopes. Photomicrographs were done with Keyence VHX 5000 digital microscope, and Kern Optics OZL 466 stereoscopic microscope mounted with Kern Optics OCD 832 (5 MPix) microscope camera. Morphological terminology was adapted from
Distribution data were recorded in Microsoft Excel program in comma-delimited text format (.csv) and processed with QGIS 3.16 “Hannover software”. WorldClim altitude raster layer (
Umbrageocoris kondorosyi Kóbor, 2019, by monotypy.
General habitus ovoid, moderately elongate. Integument shiny, with sparse, silvery pubescence at least on abdominal venter. Head pentagonal; compound eyes large, reniform, slightly stylate; posterior edge of compound eyes touching anterior edge of pronotum. Ocular sulcus complete but shallow, slightly visible. Integument of vertex impunctate, with a thin longitudinal furrow of various length, at least present on clypeus. Antenniferous tubercles minute, not visible in dorsal view. Antennomere I shortest, graniform; antennomere II longest, cylindrical; antennomeres III and IV subequal in length; antennomere III cylindrical, antennomere IV fusiform. Clypeus with margins subparallel and apex rounded, surpassing the mandibular plates. Bucculae pointed, surpassing mandibular plates; ventral margins converging, forming a Y- or cup-shaped labial trough which continues in a suture of variable length towards base of head (Figs
Umbrageocoris displays a remarkable similarity to the Australian genus Stylogeocoris in general facies [studied species: S. biroi Montandon, 1913 (lectotype,
Umbrageocoris can be distinguished from representatives of genus Geocoris distributed in the region [studied species: G. ochropterus (Fieber, 1844) (lectotype,
Umbrageocoris differs from representatives of Germalus [studied species: G. coloratus Distant, 1918 (syntype,
Representatives of the genus are distributed in continental Indomalaya and in the Indo-Australian Archipelago, from Laos to Northeast Australia (Northern Territories, Queensland, New South Wales).
1 | Labial trough cup-shaped with suture short, at most reaching middle of venter of head (Fig. |
2 |
– | Labial trough Y-shaped with suture surpassing middle of venter of head (Fig. |
4 |
2 | Pronotum with an irregular fuscous marking only at callosities; median furrow of vertex short, not exceeding base of clypeus | U. malipatili sp. nov. |
– | Pronotum with extended dark brownish to blackish markings, anterior and posterior margins with pale ochraceous transversal bands; longitudinal median furrow extending from apex of clypeus to approximately middle of vertex | 3 |
3 | Vertex mostly blackish; transversal band at posterior margin of pronotum only present medially, not reaching humeral angles; dorsal flange of peritreme indented | U. elegantulus (Distant, 1918), comb. nov. |
– | Vertex at most basally blackish; transversal band at posterior margin reaching humeral angles; dorsal flange of peritreme not indented | U. woodwardi (Malipatil, 1994), comb. nov. |
4 | Humeral angles with fuscous spots; pronotum with coarse, relatively sparse punctation, anterior and posterior margin widely impunctate (U. maai ssp.) | 5 |
– | Humeral angles undecorated or if pronotum of dark ground colour then with ochraceous marking; pronotum with relatively dense punctation; anterior and posterior margin narrowly impunctate | 6 |
5 | Pronotum anteriad to callosities with a single row of punctures, surrounding callosities; punctures posteriad to callosities forming transversal bands | U. maai timorensis Kóbor, 2019 |
– | Pronotum anteriad to callosities with more than one row punctures; pronotum posteriad to callosities evenly punctate | U. maai maai Kóbor, 2019 |
6 | Vertex and margins of pronotum dark ochraceous; pronotal callosities separated by multiple punctures | U. boonei sp. nov. |
– | Vertex entirely dark brownish or blackish, pronotum blackish with small, ochraceous spot at each humeral angle; pronotal callosities confluent | U. kondorosyi Kóbor, 2019 |
U. kondorosyi can be distinguished from other species of the genus by the entirely blackish pronotum decorated with small ochraceous spots at humeral angles; irregular brownish spots covering most of the corium; confluent pronotal callosities; and a narrow impunctate band at the posterior edge of pronotum, widened at humeral angles.
Distributed across New Guinea and adjacent islands. The species inhabits mostly rainforests, but records from mangroves and grasslands are available too.
2 m, 2 f (
U. maai maai is similar to U. boonei sp. nov. in general aspect, but the following remarkable differences enable its reliable separation from the latter species: vertex with blackish marking (lacking in U. boonei); decoration of pronotum distinctly delimited, with brownish spots at humeral angles (indistinctly delimited, somewhat blurred, spots at humeral angles lacking in U. boonei, compare Figs
The species is distributed from Thailand to Borneo and Java and has data from the following ecoregions: Northern Khorat Plateau moist deciduous forests, Southeast Indochina dry evergreen forests, Peninsular Malaysian rainforests, Kinabalu montane alpine meadows, Borneo lowland rainforests, Sundaland heath forests, and Eastern Java-Bali rainforests.
The subspecies differs from the nominotypical U. maai maai in having less extended pronotal markings and larger impunctate areas on pronotum (a single transversal line of punctures anteriad to callosities, 3–4 transversal rows posteriad to them).
The species is known from Ermera, Timor (Timor and Wetar deciduous forest ecoregion).
Holotype
, m (
Paratypes
: 2 m (
Colouration : Head ochraceous with dark brownish irregular spot at base of eye stalks posteriorly. Antennomere I ochraceous with apex irregularly brownish; antennomeres II and III entirely dark brownish; antennomere IV dark brownish with apex ochraceous. Labiomeres uniformly ochraceous. Thorax. Pronotum ochraceous with dark brownish punctation, a dark brownish or dark fuscous transversal band across callosities and irregular infuscate spot of various extent posteriad to callosities. Scutellum entirely dark brownish or blackish. Hemelytra semi-hyaline, ochraceous with dark brownish punctation and an irregular infuscate spot at apical half of corium. Thoracic pleurites and sternites dark brownish except ochraceous prosternal collar, supracoxal lobes and peritreme. Abdomen dark brownish, undecorated.
Structure : Head. Eyes slightly stylate; ocular sulcus complete, but slightly visible, rather indistinct in apical half. Ocelli situated near ocular sulci, closer to each other than to compound eyes; ratio of ocellar distance to eye ocellus distance: 1: 1.16. Dorsum of head with median longitudinal furrow extending from apex of clypeus to base of head. Relative lengths of antennomeres: 1.00: 2.40: 1.82: 4.36. Relative lengths of labiomeres: 1.00: 0.57: 0.81: 0.98. Thorax. Pronotum trapeziform with lateral margin not constricted; integument densely and deeply punctate at anterior margin and narrow pronotal callosities; pronotum length to basal width: 1.00: 1.35. Scutellum with integument densely punctate except slightly bulging, complete trifurcate carina; scutellum length to width: 1.00: 1.07. Corium submacropterous, membrane slightly surpassing apex of abdomen; corium punctate along margin of clavus, along Cu and between M-R and costa at apical half; exocorium uniformly narrow at entire length; membrane wrinkled. Thoracic sternites and pleurites densely punctate except narrow prosternal collar, supracoxal lobes and peritreme. Peritreme bulbous, situated ventrolaterally; dorsal flange with distinct peritremal surface; evaporatorium restricted to surroundings of peritreme. Abdomen. Abdominal venter with sparse, decumbent pubescence; integument of abdominal sternites III-VII corrugate dorsolaterally.
Measurements (holotype). Body length: 3.11; head length: 0.62; head width: 1.51; lengths of antennomeres I–IV: 0.14–0.33–0.25–0.60; lengths of labiomeres I–IV: 0.47–0.27–0.38–0.46; pronotum length: 0.83; pronotum width: 1.39; scutellum length: 0.72; scutellum width: 0.79.
U. boonei gen. nov. resembles both subspecies of U. maai in colouration and markings. The new species can be distinguished from other representatives of the genus by lacking an impunctate “collar” on the pronotum and its highly extended trifurcate carina on the scutellum.
The species is known from continental Indomalaya (Laos and Thailand) from the following ecoregions: Kayah-Karen montane rainforests, Luang Prabang montane rainforests, Southern Annamites montane rainforests, Chao Praya freshwater swamp forests, Indochina mangroves.
Holotype
, f (
Colouration : Head ochraceous, posterior part of eye stalks with irregular brownish marking. Eyes reddish, ocelli hyaline. Antennae missing in the single examined specimen. Labiomeres dark ochraceous. Thorax. Pronotum ochraceous with brownish punctation and an infuscate transversal band across pronotal callosities. Scutellum entirely dark brownish. Hemelytra semi-hyaline, ochraceous with brownish punctation and an irregular infuscate spot on the corium. Thoracic pleurites and sternites dark brownish except prosternal collar, supracoxal lobes and peritreme; propleurite with an ochraceous spot dorsally. Abdomen dark brownish both dorsally and ventrally with a whitish longitudinal band at dorsal part of sternites.
Structure : Head. Median furrow of vertex short, hardly surpassing base of clypeus. Antennomeres missing. Labial trough Y-shaped with suture reduced, reaching approximately midline of head. Relative lengths of labiomeres: 1.00: 0.85: 1.32: 1:38. Thorax. Pronotum with dense and deep punctation except anterior margin, pronotal callosities and posterior margin with humeral angles. Pronotal callosities confluent. Pronotum length to basal width: 1.00: 1.76. Scutellum with trifurcate carina apically reduced. Hemelytra submacropterous. Scutellum length to basal width: 1.00: 1.06. Clavus with an incomplete row of punctures at corial margin. Corium punctate along margin of clavus, Cu, between M-R and costa in apical half. Exocorium slightly widened subapically. Membrane short, not surpassing apex of abdomen.
Measurements. Body length: 4.20; head length: 0.53; head width: 1.66; lengths of labiomeres I–IV: 0.36–0.30–0.47–0.49; pronotum length: 0.88; pronotum width: 1.54; scutellum length: 0.88; scutellum width: 0.83.
U. malipatili sp. nov. resembles U. boonei sp. nov. and both subspecies of U. maai in colouration and markings, but its cup-shaped labial trough and the presence of a minute furrow on its clypeus readily distinguishes it from the Indomalayan representatives of the genus.
The single known specimen is from an unknown locality in New South Wales, Australia.
Lectotype
, m (
1 m (
Additions and corrections to the redescription of
U. elegantulus resembles U. woodwardi in general appearance but can be distinguished from the latter species based on the following characters: vertex with extended blackish markings (vertex only marked basally in U. woodwardi); dorsal flange of peritreme indented (Fig.
The species was recorded from the northern parts of Australia in the following ecoregions: Arnhem land tropical savanna, Cape York Peninsula tropical savanna, Queensland tropical rainforests, Brigalow tropical savanna (
This species was described as Geocoris elegantulus (
Dorsal habitus of Umbrageocoris species: 19. U. kondorosyi (holotype,
2 f (
Additions and corrections to the description of
U. woodwardi resembles U. elengantulus in general aspect, but it can be distinguished from the latter species based on the combination of the following characters: vertex with dark marking only basally (with more extensive dark markings in U. elegantulus); dorsal flange of peritreme simple (indented in U. elegantulus).
Most of the published records of the species are from Western Australia, where the species inhabits Brigalow tropical savanna and Eastern Australian temperate forest habitats (
Based on the specimens available as well as the original description and illustrations provided by
Umbrageocoris displays character states shared with at least one of the other three geocorine genera present in the Indomalaya and the Indo-Australian Archipelago, viz., Geocoris, Germalus and Stylogeocoris, but also possesses a number of unique character states, most importantly the shape of the labial trough or the arrangement of suture of abdominal tergites 4/5 and 5/6. The genus was originally described as monotypic with the type species U. kondorosyi (
Members of the genus Umbrageocoris apparently can be divided into an Australian and an extra-Australian lineage based on morphological differences. The Australian species (U. elengantulus, U. malipatili sp. nov. and U. woodwardi) share a shorter median longitudinal furrow on the head, reaching at most the middle of vertex (in non-Australian species this furrow always reaches the base of vertex); a cup-shaped labial trough (Y-shaped in non-Australian species); and a partly reduced hamus of the metathoracic wing (non-Australian species possess an almost complete hamus). Short-winged (brachypterous or coleopterous) and secondarily flightless species occur in all of the Australian species, whilst all known individuals of the non-Australian species are submacropterous. Based on morphological characters, the closest relative of Umbrageocoris appears to be Stylogeocoris, an endemic Australian genus, albeit the relationship between the two genera should be examined in frames of a broader phylogenetic reconstruction. Stylogeocoris is suspected to be an old, isolated faunal element of Australian lygaeoids with an area shaped by the climatic oscillation in the Tertiary (
Medially curved sutures of abdominal tergites 4/5 and 5/6 were proposed as a synapomorphy of the family Geocoridae (Henry 1997). However, the variability of this condition within the subfamilies and genera of the family has not been studied in detail. The present results suggest that this character displays generic level differences in the studied genera. A more extensive study of its taxonomic significance is therefore suggested and planned by the author.
The present work resulted in the redefinition of the genus Umbrageocoris, the description of two new species of the genus, and the revision of the generic placement of two species originally placed into the genus Geocoris. Based on the new morphological information a hypothesis regarding the origin of Umbrageocoris and its relationship to other geocorine taxa in the region was formulated. The comparative study of the sutures of abdominal tergites was proposed as a new exoskeletal character for defining genera in Geocoridae.
The author would like to express his gratitude to curators Jennifer C. Thomas (