A new genus and species of the tribe Orthotylini ( Heteroptera : Miridae : Orthotylinae ) from Central Asia

A new genus and new species, Angulonotus grisescens, is described from Kazakhstan and Uzbekistan and its taxonomic placement within the tribe Orthotylini is discussed. Illustrations of male and female genitalia, micrographs of selected characters, photographs of dorsal habitus, hosts and distributional records of this new taxon are provided. Comparisons are made with species of the genus Hyoidea Reuter, 1876.


INTRODUCTION
This paper is part of a series of ongoing efforts to improve our knowledge of the poorly known Central Asian fauna for the plant bug family Miridae.Examination of the extensive material in the collection of the Zoological Institute, Russian Academy of Sciences, revealed one new species from Kazakhstan and Uzbekistan.The new taxon described in this paper belongs to the nominotypical tribe of the subfamily Orthotylinae and cannot be assigned to any known orthotyline genus.
The Orthotylinae is the third most species-rich subfamily of Miridae and currently contains three recognized tribes (Schuh, 1976(Schuh, , 1995;;Schuh & Slater, 1995) although additional tribes, e.g., Austromirini (Carvalho, 1976), are sometimes considered as well.Classification of the largest nominate tribe is rather unsatisfactory.The unusually high variability in external morphology and the structures of the external genitalia raises doubts about the monophyly of the tribe (e.g., Yasunaga, 1999).The most distinctive and reliable feature of Orthotylini sensu lato is the presence of interramal lobes projecting dorsally from the posterior wall of the female genitalia (Slater, 1950;Davis, 1955).Schuh (1974) recognized four informal supra-generic assemblages within the Orthotylini: the Falconia, Orthotylus, Sericophanes and Zanchius groups.The Orthotylus group is by far the largest and can be recognized by the usually well-developed and sclerotized spicules in the vesica (Schuh, 1974).Almost all other characters are very variable and the group is presumably not monophyletic.Nonetheless, the new genus Angulonotus, described in the present paper, undoubtedly belongs to the Orthotylus group in its present concept.
Most Palaearctic representatives of the group differ markedly from the new genus.In particular, the genera Campylotropis Reuter, Cyllecoris Hahn, Dryophilocoris Reuter, Globiceps Lepeletier & Serville, Ulmocyllus Seidenstücker, Cyllecoridea Kerzhner, Cyrtorhinus Fie-ber, Heterotoma Lepeletier & Serville, Mecomma Fieber and Mecommopsis Kerzhner are distinguished by the more or less expressed ant-mimetic habitus, including a shiny dorsal surface and dark coloration with some light maculae.In the genus Aetorhinella Noualhier the eyes are located at a distance from the anterior margin of the pronotum.The genera Brachynotocoris Reuter, Reuteria Puton, and Ulmica Kerzhner differ from the new genus in having a short pronotal disc that covers only half of the mesoscutum.The genera, Heterocordylus Fieber and Excentricus Reuter, can be easily distinguished by the peculiar shape of their antennae.
Careful examination of the remaining Palaearctic genera in the Orthotylus group, namely Blepharidopterus Kolenati, Canariocoris Lindberg, Fieberocapsus Carvalho & Southwood, Pseudoloxops Kirkaldy, Hyoidea Reuter, Hyoidellus Wagner, Hypsitylus Fieber, Parahypsitylus Wagner, Platycranus Fieber and Orthotylus Fieber, indicates that Hyoidea is the most similar and apparently a sister taxon of the new genus described in this paper.This conclusion is corroborated by the presence of a thin pronotal collar and carinate anterolateral angles of the pronotum not observed in other Palaearctic genera in the Orthotylus group and several other characters: body proportions, coloration and structures of male external genitalia (see diagnosis).
Hyoidea was described from the Astrakhan Province of Russia by Reuter (1876) based on a single species, H. notaticeps.Its current distributional range spans the steppe and semidesert zones of the Palaearctic extending from Hungary and Slovakia in the west, through the Ukraine, Caucasus, southern European Russia and Central Asia to Northern China in the east.The second species in the genus, H. horvathi, was described by Montandon (1980) from Algeria.Later Hoberlandt (1963) revised the genus and described two species, H. lindbergi, currently known from Morocco and Tunisia, and H. kerzhneri, which has similar distributional range to H.

MATERIAL AND METHODS
All specimens examined in the course of this study, including types, are located at the Zoological Institute, St. Petersburg, Russia (ZISP).All specimens were assigned a unique specimen identifier (USI) with the contained information digitized in the Planetary Biodiversity Inventory locality database.USI is printed as a matrix code label with an alphanumeric string and mounted on one pin with the insect.USI numbers usually identify particular specimens.The associated information can be obtained from the website of the pbi/heteropteraspeciespage/) and also accessed through the www.discoverlife.orgwebsite.
Geo-reference data for each locality were obtained from gazetteers, atlases and other sources.
Dorsal photographs of the habitus of the bugs were taken using a Nikon SMZ1500 stereomicroscope equipped with Nikon D-70 camera.Photographs of the ovipositor were taken with a Leica DM 4000 microscope equipped with DIC optics.Scan-ning electron micrographs were taken using a Hitachi TM1000 Tabletop Microscope.
All measurements are in millimeters.Measurements are shown in the Table 1 and include body length, clypeus to cuneus length, head and pronotum length and width, inter-ocular distance and length of antennal segments I and II.
The terminology used for male genitalia follows Konstantinov ( 2003) and for females follows Davis (1955).

Diagnosis
Distinguished from other Palaearctic Orthotylus group genera by the following combination of characters: delicate pale body; vestiture composed of pale, long, simple, semierect setae and silvery scalelike setae; eyes located close to pronotum; second antennal segment not incrassate, slender; labium reaching middle coxae; anterolateral angles of pronotum protruding and distinctly carinate; anterior part of pronotum not delimited; mesoscutum almost entirely covered by pronotum; metepisternal scent gland evaporatory area small, without mushroom bodies; cuplike sclerite noticeably protrudes beyond margin of genital segment; parameres not serrate; aedeagus with two comparatively short spicules; dorsal lobe of interramal sclerite distinctly twin-coned; sclerotized rings of dorsal labiate plate small and distinctly ovate.Most similar to Hyoidea in that the anterolateral angles of the pronotum are distinctly carinate (compare Figs 13,14 and 16,17), thin but distinct pronotal collar (Figs 13,16,17) and several large dark spots on the frons and vertex.Angulonotus can be distinguished from Hyoidea spp.by the strongly granulated eyes with large facets (compare
Coloration.Dirty whitish to pale brown (Fig. 11).Head: pale, frons and vertex with a series of large brown and confluent spots radiating from midline, in dark specimens frons and vertex uniformly brown, with whitish midline; mandibular plate uniformly pale, maxillary plate with darkened apex, clypeus pale, somewhat darkened at sides; antenna brown; first and second labial segments yellowish, third and fourth brown.Thorax: anterior margin of pronotum usually with narrow whitish-yellow stripe, at least anterolateral angles and spot at middle whitish, calli brown to dark brown, disc dirty whitish to pale yellow, rarely pale brown, typically with four indistinctly bordered smoky pale brown longitudinal stripes; coloration of mesonotum variable, its exposed part dirty yellow to entirely brown, sometimes with pale midline and two spots at sides; scuto-scutellar suture usually dark brown, scutellum dirty yellow to pale brown, apically whitish, usually with more or less expressed pale midline; propleura yellow, meso-and metapleura brown with yellow margins.Hemelytron: dirty whitish to pale brown, with whitish lateral margin and narrowly darkened inner margin of clavus; somewhat infuscated along cuneal vein, medial fracture, medio-apical area of corium and inner margin of cuneus in pale specimens, almost uniformly pale brown in dark specimens.Legs: femora pale brown, sometimes with minute brown spots on inner surfaces; tibiae pale yellow, tarsi somewhat darker, pale brown to brown.Abdomen: dirty yellow to pale brown, with reddish markings, genital segment usually darker.
Surface and vestiture.Dorsum dull, head and hemelytron smooth, pronotum somewhat rugose; clothed with long, simple, semierect, pale setae and long, slender, scalelike setae (Fig. 18); appendages with comparatively long semierect simple pale setae, first antennal segment with three slightly infuscated mesial spines, tibial spines pale, thin and short, almost equal in length to width of 122 tibia, ventral side of abdomen covered with pale simple setae.
Structure.Head: eyes granulated (Fig. 23), ovate in lateral view, posterior margin slightly concave; facets large and convex; frons convex, vertex almost flat, with two spots of distinct ornamentation corresponding to dark spots (Fig. 25) and weak transverse posterior keel; labium reaching middle coxa; first antennal segment twice as thick as second segment.Thorax: pronotum trapeziform, with straight or slightly concave lateral margins, strongly concave anterior and posterior margins; anterolateral angles distinctly carinate (Figs 16,17); pronotal collar very thin, but distinct at sides (Figs 16,17), almost vanishing at middle; calli distinctly depressed; scutellum slightly convex, with weakly pointed apex; metepisternal scent gland evaporatory areas relatively small, triangular, without mushroom bodies, entirely covered with microtrichia (Fig. 20).Hemelytron: nearly parallel-sided; cuneus twice as long as broad; membrane of forewing relatively long, far extending beyond apex of abdomen, almost 0.15-0.2× as long as body.Legs: femora flattened, tibiae cylindrical; third tarsal segment equal in length to first and second segments combined; pretarsus with long smoothly curved claws and lamellate, apically convergent paraempodia, pulvilli absent (Fig. 21).
Genitalia.Genital segment wide, without spines or distinctive ornamentation, cuplike sclerite noticeably protruding posteriorly beyond margin of genital segment (Figs 32,33); left paramere without serrations or additional processes, L-shaped, with thin, more or less straight and gradually tapering apical process, sensory lobe well developed, with blunt apex ; right paramere more or less cylindrical, slightly bent at middle and with acute apex (Figs 49,50); aedeagus with weakly sclerotized phallotheca, two trifurcate spicules, bases of both spicules wide and enveloping sclerotized portion of ductus seminis (Fig. 55); long spicule broad basally, sharply narrowed at middle, with one smooth and two serrate branches (Fig. 56); short spicule distinctly widened at middle, with two spinelike, straight, weakly serrate branches located almost at a right angle to spicule and gradually curved, strongly serrate apical branch (Fig. 57).

Female
Similar to male, but smaller and more oval (Fig. 12).Coloration.Similar to male but generally paler.
Structure.Similar to male except larger interocular distance and less developed anterolateral angles of pronotum.
Etymology.From the Latin angulus, meaning angular and notos, meaning thorax, referring to the apical angles of the pronotum.The gender is masculine.
Discussion.Angulonotus and Hyoidea share a combination of characters that seems to be unique within the Orthotylini.Pronotal margins in both genera are distinctly carinate anteriorly or even along their entire length, whereas the anterolateral angles of pronotum are noticeably projecting.The pronotal collar is reduced but always clearly demarcated by a suture and, sometimes, by coloration.Both genera have the same type of vestiture composed of long, pale, simple setae and silvery scalelike setae.Also there is some similarity in the shape and color pattern on the head.
Most characters listed in the diagnosis occur separately in otherwise unrelated orthotyline genera, but not in combination as they do in Hyoidea and Angulonotus.For example, the presence of a weak pronotal collar is documented for Ceratocapsini or Sericophanes group sensu Schuh, 1974(e.g., Henry, 2006), lateral pronotal margin is apically carinate in the orthotyline Heterocordylus tumidicornis (Herrich-Schaeffer, 1835), whereas the collar like anterior pronotal margin in conjunction with protruding antero-lateral angles of the pronotum are present in all representatives of the austromirine Lattinovacomplex (Cassis, 2008) and the halticine Compositocoris senecionus (Schwartz et al., 2008).66,67,69,71) and more complex, distinctly asymmetrical vestibular sclerites encircling the vulva (Fig. 63).The peculiar structure of the scent gland evaporatory area seems to be a unique feature of Angulonotus, since it is entirely covered with microtrichia and devoid of peritreme and mushroom bodies.To our knowledge, this type of scent gland structure has so far not been reported in any other orthotyline genus.
Based on a preponderance of morphological evidence, we conclude that neither Hyoidea, nor any other orthotyline genus can adequately accommodate the new taxon.Thus a new monotypic genus is erected for this new taxon.

TABLE 1 .
Measurements of species of Angulonotus and Hyoidea.