First record of the plant bug genus Paramiridius Miyamoto & Yasunaga (Heteroptera, Miridae, Mirinae) from Indochina, with descriptions of two new species from Laos

Abstract The mirine plant bug genus Paramiridius, previously known only from a single Taiwanese species, is reported from Indochinese Laos for the first time and redefined. Two additional species, Paramiridius indochinensis and Paramiridius laomontanus, are described as new to science. The female genitalic structures of the genus are documented for the first time. Habitus illustrations, figures of male genitalia, and key are provided for all three known Paramiridius species.


Introduction
The mirine plant bug genus Paramiridius was proposed by Miyamoto and Yasunaga (1992) to accommodate a single species known only from Taiwan, P. tigrinus Miyamoto & Yasunaga. The genus is readily recognized by the moderate to rather large body with the conventional mirine shape and typical color pattern (yellow or yellowish green dorsum with dark stripes and maculae). However, no subsequent information has been available since the original description.
During recent field investigations undertaken by Seoul National University, 21 specimens, we perceived as belonging to Paramiridius, were collected. Upon closer examination, we can confirm that these Lao specimens represent two undescribed species of Paramiridius, herein we describe them as new to science. The present discovery also represents a range extension of the genus in Indochina. Paramiridius is redefined and diagnosed, and a key to all known species is provided. The female genitalic structures are examined and figured for the first time.

Materials and methods
All type specimens are deposited in the collection of Insect Biosystematics Laboratory, Research Institute for Agriculture and Life Science, Seoul National University, Korea (SNU). Digital images used in this paper were captured using a Diagnostic Instruments Insight Camera 14.2 Color Mosaic, with a SPOT Insight System. Specimens were dissected and observed under a Leica S8APO stereoscopic microscope.
All measurements (mean and range) are in millimeters. Terminology of the male and female genitalia primarily follows Yasunaga and Schwartz (2007), but some additional terms, such as 'lateral lobal sclerite' and 'median lobal sclerite' (Fig. 3), are used to indicate the taxonomic characters properly.

Diagnosis.
Paramiridius can be distinguished from other known mirine genera by the following combination of characters: moderate to rather large size; sparsely distributed vestiture; weakly shining, matte dorsum with noticeable dark pattern (yellow with dark stripes and maculae as in Fig. 1); generally slender antenna; six or eight dark stripes on pronotum; always wholly darkened mesoscutum; endosoma with a spicule, two (lateral and median) lobal sclerites; apically situated secondary gonopore; posterior wall of bursae with distinct interramal lobe and rather narrowed interramal sclerite; and thickrimmed sclerotized ring with a developed dorsal labiate plate. For further diagnostic characters, see Miyamoto and Yasunaga (1992). Distribution. Indochina (Laos), Taiwan. Biology. Unknown; almost all available specimens were collected using UV light traps. Two females of P. laomontanus were found on Castanea sp. (Fagaceae).
Discussion. The original authors (Miyamoto and Yasunaga 1992) mentioned Paramiridius is similar in some external characters to two western Palearctic genera, Miris Fabricus and Miridius Fieber. Nonetheless, the relationships with these genera are now considered only superficial, on the basis of completely different structures exhibited in the male genitalia.
The present work suggests Paramiridius is more probably related to Lygocoris Reuter, based on sharing the following characters: apically tuberculate phallotheca; presence of a single spicule and apically situated secondary gonopore on endosoma; and similar shape of female sclerotized rings and posterior wall. However, Paramiridius is readily distinguished from Lygocoris by the unique dark pattern on the dorsum which is nearly matte and glabrous, the different shape of the parameres, and the posterior wall of bursae lacking a lateral lobe (for principal diagnostic characters of Lygocoris, see Yasunaga 1991).
There are quite a few mirines superficially similar to Paramiridius. To demonstrate more reliable systematic position of the genus, further comprehensive revision is required, including the acquisition of DNA sequence data for representatives of all related genera, a long-run task far beyond the scope of this study. Diagnosis. Recognized by the characters given in the key, and the tapered hypophysis of the right paramere (Fig. 2), the developed, curved endosomal spicule (Fig. 3), and the wide, squared interramal lobe (Fig. 2). Most closely related to P. tigrinus, from which this new species can be distinguished by the preceeding diagnostic characters. Description. Coloration: Body generally yellow; dorsum with black-striped patterns (Fig. 1). Head yellow, medially black; eye margin black. Antenna almost entirely dark brown without pale portions. Labium shiny yellowish brown; segment IV darkened. Pronotum yellow, with three pairs of black stripes (each pair fused together posteriorly); and with narrowly yellow posterior margin. Mesoscutum wholly black. Scutellum medially black; lateral part and apex yellow. Hemelytron widely blackish brown, with three pairs of yellow stripes each along claval vein, claval suture and R+M vein (Fig. 1); posterior half of clavus, anterior quarter to half part of corium, anterior two-third of embolium and entire cuneus yellow. Coxa pale yellow; leg yellow; each femur with more or less darkened apical part; each tibia yellow, with a dark, subbasal annulation and darkened apex; all tarsi brown.

Key to
Structure and vestiture: As in generic description provided by Miyamoto and Yasunaga (1992). Body elongate, parallel-sided; dorsal vestiture generally short, simple, and only sparsely distributed. Head vertical; vertex apparently wider than an eye in dorsal view. Labium reaching middle part of metacoxa.
Measurements ♂/♀: Diagnosis. Recognized by the characters in the key, and the modified shape of the parameres (Fig. 2), and the well-developed lateral lobe and short spicule on the endosoma (Fig. 3). By these characters, P. laomontanus can be readily distinguished from other congeners.
Description. Coloration: Body yellow, often tinged with green, with black maculae and stripes. Head yellow, with paired, symmetrical, dark maculae on vertex; frons with a black stripe medially; clypeus darkened basally. Antenna dark brown to black; extreme bases of segments II and III white. Labium dark brown, except for yellowish segment II. Pronotum greenish yellow, with three pairs of black stripes not reaching pale posterior margin of pronotum. Mesoscutum and scutellum yellow, with symmetrical, dark patterns. Hemelytron pale green or greenish yellow, with variable black patterns as in Fig. 1; inner margin of clavus, and apical half of embolium blackish brown. Coxa pale yellowish brown, with a dark spot basally; leg yellowish brown; proand mesofemur with dark brown spots; apex of each femur more or less darkened; all tibiae and tarsi dark brown.

Diagnosis.
Recognized by the characters mentioned in the key, and the broader yellow posterior margin of the pronotum, the slender, blunt-tipped hypophysis of the right paramere, and the straight endosomal spicule (See Miyamoto and Yasunaga 1992). Distribution. Taiwan.