Description of eight new species of the traumatically inseminating plant bug genus Coridromius (Heteroptera: Miridae: Orthotylinae: Coridromini)

Eight new species of the plant bug genus Coridromius are described: C. basilanus sp. nov. from the Philippines, C. eremnos sp. nov. from Sabah, Malaysia, C. fomangsu sp. nov. and C. tafo sp. nov. from Ghana, C. norfolkensis sp. nov. from Norfolk Island, Australia, C. mulu sp. nov. from Sarawak, Malaysia, C. macchabeeus sp. nov. from Mauritius, and C. taravao sp. nov. from Tahiti, French Polynesia.


Introduction
The plant bug genus Coridromius Signoret, 1862 (Heteroptera: Miridae) has a paleotropical distribution, and is found from West Africa to the tropical islands of the Pacifi c, with one species recently introduced to the Americas (Tatarnic & Cassis 2008;Carpintero & Guarda 2011). Coridromius is unique among the Miridae in that all species mate via traumatic insemination, whereby males use their hypodermic intromittent organ (formed by coupling of the left paramere with the aedeagus as in bed bugs -see Carayon 1966) to stab females in the abdomen during mating, completely bypassing the female genitalia (Tatarnic et al. 2006). Presumably in response to the costs associated with traumatic insemination (for discussion of related costs in bed bugs, see Morrow & Arnqvist 2003;Reinhardt et al. 2003;Siva-Jothy 2006), females of several species have evolved paragenital structures at the site of insemination (Tatarnic et al. 2006;Tatarnic & Cassis 2008;Tatarnic & Cassis 2010), analogous to the ectospermalege and mesospermalege of bedbugs (Carayon 1966).
First described by Montrouzier (1861) under the name Ocypus, Coridromius has always been problematic taxonomically. Initially placed in the tribe Orthotylini Van Duzee, 1916 (Schuh 1974;Linnavuori 1994), Coridromius was more recently moved to the Halticini (Cassis & Gross 1995;Schuh 1975Schuh ), presumably http://dx.doi.org/10.5852/ejt.2013 www.europeanjournaloftaxonomy.eu 2013 · Tatarnic  based on the lack of interramal lobes on the posterior wall of the female genitalia (the authors did not explicitly justify their decision, though a lack of interramal lobes was said by Schuh (1974) to always distinguish the Halticini). Following a phylogenetic analysis and revision of the Halticini Costa, 1853 , Coridromius has since been removed from this tribe to form its own monogeneric tribe, the Coridromini  Some of the newly presented species are described from single specimens. While such descriptions are generally to be avoided, we are confi dent in our assessment, based on the characters we have documented and our deep knowledge of the genus (we have collectively looked at virtually every museum specimen of Coridromius, and have described or redescribed every known species: see Tatarnic & Cassis 2008).

Material and Methods
This paper reports fi ve new species discovered in existing museum collections as well as three new species (Coridromius mulu sp. nov., C. norfolkensis sp. nov., C. taravao sp. nov.) discovered through recent collecting efforts. Species descriptions and terminological usage follow Tatarnic & Cassis (2008). Acronyms AI through AIV refer to antennal segments. All examined specimens are labelled with matrix code labels, providing each specimen with a "unique specimen identifi er" (USI). These USI codes include a project code followed by a unique eight-digit number (e.g., UNSW_ENT 00000028 is the USI for the holotype of C. taravao sp. nov.). USI codes are listed in the specimens examined, which also include all available collection data as provided on labels, such as collector, date, host plant data, and georeferencing information. All specimen information has been entered into the Planetary Biodiversity Inventory plant bug database (https://research.amnh.org/pbi/), and is available to the public via Discover Life (www.discoverlife.org) and Heteroptera Species Pages (http://research.amnh.org/pbi/ heteropteraspeciespage).
All measurements are in millimetres. Because the hemelytra in Coridromius are strongly declivent at the base of the cuneus, the total body length is recorded as the distance from the clypeus to the cuneal fracture. Habitus images were taken using a Visionary Digital system equipped with an Infi nity Photo-Optical K-2, 3-lens system and a Canon EOS 40D digital camera (www.visionarydigital.com). Images presented are derived from multiple photographs, concatenated using Helicon focus (www.heliconsoft. com). Scanning electron micrographs were taken with a Hitachi TM3000 tabletop microscope.

Diagnosis
Most similar to C. declivipennis Tatarnic & Cassis, 2008 but distinguished by the shape of the ventral apical process of the pygophore, which is reduced to a truncate, rounded tumescence (versus a broad rounded lobe in C. declivipennis: see Tatarnic & Cassis 2008: Fig. 11).

Etymology
Named for the type locality.

Host
Unknown.

Remarks
This is the third species to be described from the Philippines, the others being C. ephippius Cassis, 2008 andC. marmoreus Tatarnic &Cassis, 2008. The characteristic fl aring of the hemelytron distinguishes C. basilanus sp. nov. from its Philippine congeners, as does its predominantly pale orangebrown colouration (C. marmoreus is distinctly speckled in colour, while C. ephippius is considerably darker, with AII apically brown). Coridromius basilanus sp. nov. appears most similar to C. declivipennis, which is known only from Okinawa, Japan (Tatarnic & Cassis 2008).

Diagnosis
Recognized by the following combination of characters: body uniformly black with pale silvery hairlike setae; head black with yellow margins; antennae banded dark brown and pale yellow; proepimeron bilobed.

Etymology
Named for the Greek eremnos, meaning black.    Fig. 2A-B). Almost entirely dark brown/black, with some white and pale yellow markings. Head: Black with pale yellow trim along inner ocular margin and posterior margin ( Fig.  2A-B). Labium with fi rst segment dark brown, the remainder orange-yellow. Antennae: AI dark brown with white apices, AII dark brown with narrow white medial annulation, AIII and AIV dark brown with white basal annulation ( Fig. 2A). Thorax: Pronotal collar, pronotum, mesoscutum and scutellum uniform dark brown/black ( Fig. 2A). Thoracic pleura dark brown/black. Anterior proepimeral lobe white, posterior lobe black. Evaporative area of metathoracic scent gland orange-yellow. Hemelytra: Uniform dark brown/black, membrane brown with dark brown veins. Abdomen: Dark brown/black. Legs: Pro-and mesofemora dark brown with apical ¼ orange-yellow, pro-and mesotibia orange-yellow with faint brown subbasal annulations, metatibia and metafemur uniform dark brown, metafemur without transverse banding. All tarsi yellow with claws brown. SURFACE AND VESTITURE ( Fig. 2A-B). Head, pronotum, thoracic pleura, scutellum, and hemelytra impunctate. Body clothed in long, white, decumbent setae [most setae knocked off the specimen].
HEAD. Approximately 5.6 x as wide as eye in anterior view (Fig. 2B). Frons strongly medially tumescent, merging with two minor swellings adjacent to eyes. Posterior margin of head rounded, weakly carinate. Antennae shorter and stouter than in other species, with AII slightly less than width of head (AII > than head width in others) ( Fig. 2A).

Host
No host plant data.

Distribution
Known only from Sabah.

Remarks
Only one other species, C. nigrus Carvalho, 1987 shares a nearly uniform black colouration. However, these species are readily separated by the proepimeron (unilobed in C. nigrus, bilobed in C. eremnos sp. nov.), and the female paragenitalia, which in C. nigrus is recognised by a well-defi ned swelling of the right abdominal laterotergites II and III, and the posterior margin of abdominal sternite II strongly carinate and fl ared to expose a putative copulatory opening.

Diagnosis
Distinguished from all other species by a combination of the following features: the uniform yelloworange colouration, the unique form of the right paramere, and the callosite region with two broad swellings bordered laterally by deep sulci.

Etymology
Named after the type locality of South Fomangsu Forest Reserve. Antennae clothed in semi-decumbent hairlike setae interspersed with a few more erect, thin, spinelike setae ( Fig. 2C). Pronotum with sparse distribution of short, reddish-brown reclining setae, hemelytra with sparse distribution of short, pale, semi-reclining setae and shorter, reddish-brown setae. Abdomen with slightly more dense coating of longer, semi-erect setae. Femora with thick, reddish-brown, semierect setae, longer on ventral surface. Tibiae with thick, pale semi-erect, setae, metatibia with two rows of thick, caudally directed spines.
HEAD. Approximately 5.6 x as wide as eye ( ABDOMEN. Posterior margin of abdominal sternite II not distinctly angular in lateral view. MALE GENITALIA. Pygophore with mesal longitudinal suture elongate, right side of suture with apical apophysis lying transversely across pygophore margin (Fig. 2F). Left paramere a short, thick, angular scythe slightly twisted along its axis, right paramere cleft, with inner lobe elongate and outer lobe short and rounded (Fig. 2E). FEMALE PARAGENITALIA. Unknown.

Host
No host records.

Distribution
South Fomangsu National Park, Ghana.

Remarks
Coridromius fomangsu is one of three species now known from Ghana (the others being C. tafo sp. nov. described herein, and C. lestoni Tatarnic & Cassis, 2008), and one of fi ve now known from Africa. All three Ghanan species are readily distinguished by size, colouration and male genitalia. In particular, C. fomangsu sp. nov. is the only species in the genus with a right paramere of this form.

Diagnosis
Recognised by the following combination of characters: frons nearly fl at, smooth and shining, pronotum densely punctate with well-demarcated callosite region, and proepimeron unilobed.
ABDOMEN. Posterolateral margin of second abdominal sternite relatively straight. FEMALE PARAGENITALIA. Right second abdominal sternite swollen, posterolateral margin slightly fl ared and carinate, exposing a copulatory groove leading to site of penetration (Fig. 3D).

Host
Unknown.

Distribution
Known only from the type locality.

Remarks
This is one of several species that have been discovered from examination of undetermined material at the Natural History Museum, London. Based on this sole specimen, we cannot comment on whether or not this species is endemic to Mauritius or has a wider distribution.

Diagnosis
Recognized by the following combination of characters: pronotum, scutellum, and thoracic pleura punctate; proepimeron bilobed; mostly tan colouration with dark brown markings on hemelytron adjacent to scutellum; right paramere with thumblike process; posterior margin of pygophore with long mesal longitudinal suture and broad triangular projection; caudal margin of metepimeron infl exed and abutting anterolateral margin of abdomen; and female with right anterolateral margin of abdomen slightly swollen and desclerotized, sometimes with small melanised scars.

Etymology
Named for the national park from which it was collected.  (2013) and posterior margin of head cream to yellow (Fig. 4B). Clypeus pale yellow, gena, mandibular and maxillary plates yellow, buccula pale brown basally with small darker brown marking, white along ventral margin. Labrum brown basally, white at apex. Labium white, brown apically. Antennae: AI pale yellow with broad, dark brown annulation medially, AII mostly pale orange-brown, apically dark brown, subapically with prominent narrow white annulation, sometimes slightly darker below this, AIII and AIV dark brown, white basally ( Fig. 4A-C). Thorax: Pronotal collar yellowed with dark brown markings at lateral margins. Pronotum mostly orange-brown with darkened punctures and faint yellow midline, anterior margin with two small dark brown markings behind eyes, calli and humeral angles faintly darkened, yellow along lateral and caudal margins (Fig. 4A-B). Mesoscutum orange-brown with darker brown punctures. Scutellum pale to orange-brown with darkened punctures and faint white to pale yellow midline, apex and basal corners (Fig. 4A). Processes of proepimeron white, thoracic pleura orange-brown with darker brown punctures, posterior margins pale yellow to white (Fig. 4C). Hemelytra: Mostly orange-brown with dark brown punctures and yellow and dark brown markings. Clavus basally orange-brown, dark brown adjacent to scutellum, yellow to cream coloured along claval commissure, corium orange brown with broad, dark brown marking in line with claval commissure, becoming yellow toward apex, embolium yellow with orange-brown to dark brown medial marking, cuneus yellow-brown to brown, with darker brown punctures, membrane brown with dark brown veins (Fig. 4A). Abdomen: Mostly orange-brown, becoming yellowed along dorsolateral margin, segment II orange-brown (Fig. 4C). Abdomen of some specimens with faint green tint. Legs: predominantly pale cream-colored. Metafemur darker orange-brown dorsally, with faint diagonal brown stripes on outer surface, metatibia with narrow dark brown apical annulation, caudally facing spines dark orange-brown (Fig. 4C). Tibiae faintly darkened apically. SURFACE AND VESTITURE (Fig. 4A-F). Head, pronotum, thoracic pleura, scutellum and hemelytra punctate ( Fig. 4A-E). Body clothed in long, white, decumbent setae ( Fig. 4A-F). Left posterior margin of abdominal sternite VIII of male with a patch of dense, conelike setae (Fig. 4F).

Host
Collected from the male fl owers of an unidentifi ed species of Homalanthus (Euphorbiaceae) (Fig. 4G).

Distribution
Collected outside Deer Cave in Gulung Mulu National Park, Sarawak, Malaysia.

Remarks
This species was found exclusively on the male fl owers of its host plant, an unidentifi ed species of Homalanthus. Coridromius mulu sp. nov. is one of seven species now known from Borneo, most of which are known from a single locality. In this species the site of insemination in females (at the anterior margin of the abdomen) is sometimes marked with small melanised scars. Internal paragenital structures have yet to be examined in this species.

Diagnosis
Recognized by the following combination of characters: anterolateral margins of hemelytra strongly projecting laterally; proepimeron unilobed; posterior margin of metepimeron angled inward and abutting the anterior margin of the abdomen.

SURFACE AND VESTITURE
HEAD. Approximately 6.8 x as wide as eye (Fig. 5B) in anterior view. Frons weakly convex with paired minute tumescences adjacent to eyes, bordered posteriorly by shallow, transverse sulcus (Fig. 5B). When viewed from front posterior margin of head slightly rounded medially but otherwise fl at (Fig. 5B).

Hosts
Presently known only from the invasive weed Schinus terebinthifolius (Fig. 5C), but thought to be originally associated with one of the several species of Euphorbiaceae native to the island.

Distribution
Restricted to Norfolk Island.

Remarks
On a recent trip to Norfolk Island, C. norfolkensis sp. nov. was found in large numbers on the introduced weed Schinus terebinthifolius, known as Brazilian pepper (Anacardiaceae: also called Hawaiian holly). This weedy invasive was fi rst introduced to Norfolk Island in the 1920s, and has now spread throughout the island (Margaret Christian, pers. comm.). A native of South America, it is also a pest in Hawaii, Florida, New Caledonia, Fiji, Tahiti, and Mauritius (Meyer 2000). It is worth noting that the recently discovered species C. taravao sp. nov. from Tahiti (described below) has also been found in large numbers on Brazilian pepper, which is also an invasive weed in French Polynesia. Ironically, while native habitat has been severely degraded by human settlement in both of these oceanic islands, this human introduced weed may end up providing a viable habitat for these and other endemic species.

Diagnosis
Distinguished by the following combination of characters: pronotum with anterior margin steeply declivent and posterior margin cleft, left paramere evenly curved, gutter of left paramere nearly enclosed its entire length, and ventral apical process of pygophore broad.

Host
No host records.

Distribution
Known only from Tafo, Ghana.

Remarks
In 1974, Linnavuori described C. schuhi from a single specimen collected on Mount Tonkoui, Ivory Coast (Linnavuori 1994). Unfortunately, the sole specimen of this species appears to have been lost (Tatarnic & Cassis 2008), and its description lacks suffi cient detail to determine whether or not it is conspecifi c with C. tafo sp. nov. Though the described colouration of C. schuhi differs from that of the sole specimen of C. tafo sp. nov. (the former being much darker), other species of Coridromius are highly variable in their colouring (e.g., C. chenopoderis Tatarnic & Cassis, 2008;C. zetteli Chérot, Konstantinov & Yasunaga, 2004: see Tatarnic & Cassis 2010, and without a larger sample size we cannot ascertain the degree of colour variation across these species. We therefore take the conservative approach in designating C. tafo sp. nov. a distinct species.

Diagnosis
Distinguished by the following combination of characters: relatively small size, overall pale green/brown colour with matte yellow scutellum, frons without vittae, and brown diagonal stripes on metafemur faint or absent, and females with right anterior abdominal laterosternite slightly swollen, blackened and heavily sclerotized. COLOURATION ( Fig. 7A-C). Both sexes usually pale tan-brown with a greenish tint and conspicuous yellow scutellum; females rarely predominantly darker brown. Head: pale brown, frons without vittae, inner ocular margin and posterior margin of head pale yellow (Fig. 7A). Clypeus, mandibular and maxillary plates cream to brown (Fig. 7A). Buccula orange-brown in some specimens, in others basally yellowbrown to pale green, white along ventral margin. Labrum orange-brown. Labium cream basally, becoming brown towards apex. Antennae: mostly orange-brown. AI pale cream, AII orange-brown, Apex of AII, and AIII-AIV darker brown (Fig. 7B-C). Eyes red. Thorax: Pronotal collar cream (Fig. 7A). Pronotum pale tan-brown with irregular black markings before caudal margin in some specimens, caudal margin yellow (Fig. 7C). Scutellum matte yellow (Fig. 7C). Thoracic pleura predominantly orange-brown (Fig.  7B). Hemelytra: mostly pale orange-brown, with a faint green tint on corium, inner margin of clavus and claval commisure blackened, forming a distinctive Y-shaped pattern, membrane hyaline, veins nearly indistinguishable (Fig. 7C). Abdomen: Faintly tinted green in both sexes, in female with fi rst visible segment on right side (paragenital region) embrowned with leading edge dark black (Fig. 7B). Legs: All coxae cream, pro-and mesofemora cream, faintly orange-brown at apex, metafemur mostly cream, sometimes with faint brown diagonal striping on outer surface, apical ¼ orange-brown (Fig. 7B). All tibiae yellow to yellow-brown, apically tinted brown or green in some specimens; tarsi pale, apically embrowned (Fig. 7B). Females almost always coloured identically to males, rare individuals are much TATARNIC N.J. & CASSIS G., Eight new species of Coridromius (Heteroptera) darker, with dorsum predominantly darker brown, scutellum embrowned, hemelytra with faint dark brown chevron immediately above cuneus, abdomen brown and apices of femora embrowned. SURFACE AND VESTITURE (Fig. 7A-C, E). Head shallowly punctate, pronotum fi nely punctate, thoracic pleura, scutellum and hemelytra impunctate. Body with sparse covering of short, hairlike, decumbent setae. Both sexes with patch of elongate setae on right side of abdomen.

Etymology
HEAD. Approximately 5.7 x as wide as eye (Fig. 7A) in anterior view. Frons weakly tumescent medially, vertex with faintly raised tumescences adjacent to eyes, bordered above by shallow depressions, posterior margin of head weakly carinate, when viewed from front weakly convex medially but otherwise fl at (Fig. 7A).
LEGS. Metatibial spines short and thin (Fig. 7B). Abdomen: Posterior margin of abdominal sternite II (fi rst visible sternite) weakly convex in lateral view, females with anterior margin on right side heavily sclerotized and swollen (Fig. 7B). MALE GENITALIA. Posterior margin of pygophore with folded groove to right of centre, right margin of groove with small, triangular apophysis (Fig. 7F). Left paramere approximately 2.5 x length of right paramere, evenly curved with gutter accommodating aedeagus open its entire length, right paramere broad and subtriangular (Fig. 7F). FEMALE PARAGENITALIA. Anterior of right abdominal sternite II (fi rst visible abdominal sternite) weakly swollen and heavily sclerotized; posterior margin of metepimeral lobe defl ected inward and interlocking on right side with anterior swelling of sternite II (Fig. 7B, E). Female site of insemination unknown, thought to be stabbed either along anterior or abdomen adjacent to metacoxa, concealed by metepimeral lobe, or possibly on the other side of the abdomen, in a shallow depression behind the metepimeral lobe.

Distribution
Presently known only from Taravao Plateau and the base of the Belvedere Trail, Rau Ape Aorai, Tahiti Island.

Remarks
The new species was collected, along with the superfi cially similar C. tahitiensis Tatarnic & Cassis, 2008, at the same two localities and from the same host plants. All but a few female C. taravao sp. nov. share the same colouration as male C. tahitiensis, and are often diffi cult to identify without careful examination of the metepimeral lobe (defl ected inwards in C. taravao sp. nov., extended caudally in C. tahitiensis) and the female paragenitalia (in C. taravao sp. nov. as described above, in C. tahitiensis manifested as a large invaginated copulatory sinus between abdominal sternites II and III).

Discussion
Coridromius species exhibit a Wallacean distribution, with distinct, phylogeneticlly supported eastern and western species groups (Tatarnic & Cassis 2010). Species in the eastern group are most easily recognized by their unilobate proepimeron, as well as the generally triangular shape of the right paramere, while those of the western group exhibit a bilobed proepimeron and the right paramere is usually (though not always) club-shaped with a thumb-or spinelike apophysis. The species described herein mostly conform to this trend: the "western species" C. basilanus sp. nov., C. eremnos sp. nov., C. fomangsu sp. nov., C. mulu sp. nov., and C. tafo sp. nov. all display a bilobed proepimeron and (in those species where the male is known) a western type right paramere, whereas the eastern species C. norfolkensis sp. nov. and C. taravao sp. nov. have a unilobed proepimeron and triangular right paramere. This distinction is not perfect however, with the Mauritian species C. macchabeeus sp. nov. displaying a proepimeron that is apparently intermediate between the two types. At fi rst glance the proepimeron appears unilobed, but closer inspection reveals a reduced anterior lobe that is partly obscured by the posterior lobe and the eye (Fig. 3C). Similarly, the right paramere of C. fomangsu sp. nov. from Ghana bears a unique apophysis unseen in other Coridromius. We suspect that further collecting in Africa will yield additional new species, possibly bearing similar morphological departures from the norm. Until we achieve greater representation of African species, we cannot yet say whether these will form one or several subclades distinct from the more thoroughly represented Southeast Asian and Austral Pacifi c species.
Coridromius was originally considered rare in collections (Schuh 1974), and until quite recently was only known from 10 species. With a recent revision of the genus (Tatarnic & Cassis 2008) the number of described species was extended to 33, and in the present paper we add an additional eight. We anticipate that with further, targeted collecting in undersampled regions -particularly in Africa and Southeast Asia -many new species remain to be discovered.