Isometopus siamensis Yasunaga & Yamada, n. sp.
Creators: name: Yasunaga, Tomohide
name: Yamada, Kazutaka
name: Artchawakom, Taksin
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Miridae
Isometopus
Isometopus siamensis

description: Isometopus siamensis Yasunaga & Yamada, n. sp.
(Figs. 1–3)
Diagnosis. Readily recognized by the generally shiny blackish basic coloration, large compound eye, infuscate antennal segment I, and form of the parameres. Sexual dimorphism is minor (Fig. 1). The present new species is most closely related to a continental Chinese I. puberus Ren, 1991, from which it can be distinguished by the above mentioned characters. Isometopus siamensis is at first sight confusable with certain species of the Anthocoridae, e.g. Wollastoniella parvicuneis Yasunaga or W. rotunda Yasunaga & Miyamoto (see Yamada et al., 2010), but any isometopine always has the closed membrane cell as in other mirid bugs (Fig. 2 A).
Description. Body generally blackish chestnut brown, rounded oval; dorsal surface shining, densely punctate, with uniformly distributed, pale, simple, reclining setae (Fig. 1). Antenna mainly yellow, with densely distributed, long, erect setae, especially on thickened segment II; segment I fuscous; segments III and IV filiform. Labium shiny chestnut-brown, long, reaching apex of metacoxa. Pronotum short, about 1/3 as long as wide, with finely and narrowly upturned anterior margin; thoracic pleura wholly fuscous; apex of scutellum attaining near base of membrane. Hemelytron shiny dark brown; cuneus somewhat paler in dried specimens; membrane sombre brown, with narrow, single-celled venation. All coxae and femora shiny chestnut-brown; metafemur tumid, lamellate; apex of each femur, and all tibiae and tarsi yellowish-brown; tarsus 2-segmented (Fig. 3 B). Abdomen shiny chocolate-brown. Male genitalia (Figs. 2 C, 3C–E): Parameres hairless, long, slender; left paramere with elongate base; endosoma almost entirely membranous.
Measurements (3/ Ƥ). Total body length 1.71/ 1.86; head width across compound eyes 0.74/ 0.74; head height 0.38/ 0.37; vertex width 0.25/ 0.25; lengths of antennal segment I-IV 0.12, 0.45, 0.25, 0.17/ 0.11, 0.42, 0.25, 0.16; labial length 0.88/ 0.89; mesal pronotal length 0.37/ 0.38; basal pronotal width 1.10/ 1.10; width across hemelytron 1.30/ 1.30; lengths of metafemur, tibia and tarsus 0.55, 0.63, 0.15/ 0.49, 0.74, 0.20.
Etymology. Named for its occurrence in Siamese country, or Thailand.
Distribution. Thailand (Nakhon Ratchasima Prov.).
Biology. Unknown; all known specimens were collected by a light trap. As documented by Wheeler (2001) and Yasunaga (2001, 2005), the isometopines are known particularly to inhabit barks of various trees and are presumably diurnal. Within the Isometopinae, the present new species is unusual, having a phototactic habit.
Holotype. 3, THAILAND: Nakhon Ratchasima Prov.: SERS, 14˚30 27″N, 101˚5539″E, 410 m alt., light trap, 3 Jun 2012, T. Yasunaga (AMNH _PBI 00379601) (SUT).
Paratype. 1Ƥ, same data as for holotype except for date 2 Jun 2012 (00379602) (TYCN).
description: Published as part of Yasunaga, Tomohide, Yamada, Kazutaka & Artchawakom, Taksin, 2013, A new species of Isometopus Fieber, the first record of Isometopinae (Heteroptera: Miridae) from Thailand, pp. 197-200 in Zootaxa 3599 (2) on pages 197-199, DOI: 10.5281/zenodo.217673