Coridromius norfolkensis, Tatarnic and Gerasimos Cassis & Nsw & Nsw, 2013

Tatarnic, Nikolai J. & Cassis, Gerasimos, 2013, Description of eight new species of the traumatically inseminating plant bug genus Coridromius (Heteroptera: Miridae: Orthotylinae: Coridromini), European Journal of Taxonomy 35, pp. 1-24 : 14-17

Coridromius norfolkensis sp. nov.

Fig. 5 A-F

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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.

Etymology

This name was chosen to reflect the species’ endemic distribution on Norfolk Island.

Type material

Holotype

♂, AUSTRALIA: Norfolk Island, Ball Bay, end of Marsh Road, 29.04816° S – 167.98024° E, 69 m, 22 Apr. 2011, N. Tatarnic & A. Namyatova, ex. Schinus terebinthifolius Raddi, 1820 (Anacardiaceae) ( AMNH_PBI 00019666 ) ( AM).

Paratypes

AUSTRALIA: Norfolk Island, Ball Bay, end of Marsh Road, 29.04816°S 167.98024°E, 69 m, 22 Apr. 2011, N. Tatarnic & A. Namyatova, Schinus terebinthifolius (Anacardiaceae) , 10 ♂♂ ( UNSW _ENT 00019667–00019676), 2 ♀♀ ( UNSW _ENT 00019677–00019678) ( AM), Schinus terebinthifolius (Anacardiaceae) , 5 ♂♂ ( UNSW _ENT 00000021–00000025), 1 ♀ ( UNSW _ENT 00000026) ( UNSW); Norfolk Island National Park, Mt Bates, 29.01° S – 167.56° E, 300 m, 07 Apr. 1984, E. D. Edwards, 1 ♂ ( UNSW _ENT 00034129), 1 ♀ ( UNSW _ENT 00034130) ( ANIC) and 08 Apr. 1984, E. D. Edwards, 2 ♂♂ ( UNSW _ENT 00034131, UNSW _ENT 00034132) ( ANIC); Palm Glen entrance to Norfolk Island National Park, 29.02503° S – 167.95194° E, 129 m, 20-21 Apr. 2011, N. Tatarnic & A. Namyatova, Schinus terebinthifolius (Anacardiaceae) , 3 ♂♂ ( UNSW _ENT 00000017–00000019), 1 ♀ ( UNSW _ ENT 00000020) ( UNSW); Corner of Prince Phillip Dr and Red Rd, 29.01804° S – 167.95795° E, 186 m, 22 Apr. 2011, N. Tatarnic & A. Namyatova, Schinus terebinthifolius (Anacardiaceae) , 2 ♂♂ ( UNSW _ENT 00046008–00046009), 1 ♀ ( UNSW _ENT 00046010) ( BPBM), Schinus terebinthifolius (Anacardiaceae) , 1 ♂ ( UNSW _ENT 00000027) ( UNSW).

Description

BODY LENGTH. ♂ (n = 5): 1.84-2.04 mm, ♀ (n = 5): 1.89-2.01 mm.

COLOURATION ( Fig. 5 A-D). Mostly pale brown with cream and darker brown markings. Head: Mostly brownish-yellow with dark brown vittae on frons, posterior of head with transverse orange-brown marking, inner ocular margins and posterior margin of vertex cream, paired minor swellings on vertex white, bordered posteriorly with dark brown transverse markings ( Fig. 5B ). Clypeus cream coloured, basally with median irregular dark brown spot, laterally and apically with irregular brown markings, mandibular and maxillary plates pale ( Fig. 5B ). Buccula cream, basally brown, labrum cream ( Fig. 5A ). Labium cream, brown apically. Antennae: AI pale yellow-brown with or without faint, thin brown apical annulation, AII orange-brown, dark brown at apex, AIII and AIV orange-brown, slightly darker at base ( Fig. 5 A-B, D). Thorax: Pronotal collar yellow-brown with darker brown anterior and posterior margins ( Fig. 5B, D ). Pronotum orange-brown, medially with faint, pale midline, anteriorly with transverse field of dark brown spots either side of midline, medially with paired transverse brown markings, tapering towards lateral margins, faintly browned at humeral angles and along posteromedial margin ( Fig. 5 B- D). Mesoscutum orange-brown with broad, paired black triangular markings on either side of midline ( Fig. 5D ). Scutellum orange-brown with black midline narrowing to apex, basally and laterally with dark brown to black spots, basal corners orange-brown, bordered posteriorly by faint cream markings, apically cream ( Fig. 5D ); in some specimens with prominent paired cream apical markings to either side of midline, occupying much of scutellum ( Fig. 5C ). Propleuron orange-brown with yellowed posterior margin ( Fig. 5A ). Mesopleuron orange-brown dorsally, becoming black ventrally, yellowed along posterodorsal margin and adjacent to mesocoxa ( Fig. 5A ). Metepimeron mostly orange-brown, yellowed along peritreme ( Fig. 5A ). Hemelytra: Mostly orange-brown. Claval commissure dark brown, corium with transverse brown markings medially and vertical brown markings caudally, apex of embolium brown, cuneus dark brown basally, orange-brown towards apex, membrane pale brown with darker veins ( Fig. 5 C-D). Legs: Coxae cream ( Fig. 5A ). Pro- and mesofemora cream with faint to pronounced, subapical brown band, metafemur cream basally, with nine contrasting dark brown stripes on outer surface bordered apically with faintly reddened patch, becoming brown towards ventral surface, apically mostly dark brown, with faintly reddened subapical lateral sulcus ( Fig. 5A ). Pro- and mesotibiae cream basally, quickly becoming darker brown, slightly orange or red towards apex. Metatibia pale orangebrown to darker chocolate brown, pale basally ( Fig. 5A ). Tarsi cream, brown apically. Abdomen: Mostly cream, males with dorsolateral margin with broad brown band, becoming reddened towards apex, anterolateral margin adjacent to metathorax often darkest brown ( Fig. 5A ).

SURFACE AND VESTITURE ( Fig. 5 A-F). Head glossy and shallowly punctate ( Fig. 5B ), pronotum and scutellum shallowly punctate ( Fig. 5D ), propleuron, metepimeron, and hemelytra impunctate ( Fig. 5 D- E). Head with sparse distribution of short, white setae ( Fig. 5B ). Pronotal collar with semierect short white setae. Pronotum, thoracic pleura, abdomen and legs with short, white, decumbent setae. Caudally directed spines of metatibia short and thin ( Fig. 5A ).

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 flat ( Fig. 5B ).

THORAX. Pronotum broad and weakly rounded, lateral margins thinly carinate, posterior margin almost straight, weakly medially cleft, submarginal region of humeral angles weakly excavate ( Fig. 5D ). Proepimeron unilobed ( Fig. 5A ). Posterior margin of metepimeron curved inwards, closely adpressed to and partially obscured by abdomen ( Fig. 5E ). Scutellum weakly swollen ( Fig. 5D ).

HEMELYTRA. Embolium thin, anterolateral margin distinctly flared ( Fig. 5D ).

LEGS. Metafemora incrassate, metatibia rectilinear, paired row of caudally directed spines thin and short ( Fig. 5A ).

ABDOMEN. In female anterolateral margins slightly swollen, particularly on right. Posterior margin of abdominal sternite II mostly vertical, not sharply angular ( Fig. 5E ) in lateral view.

MALE GENITALIA. Right paramere triangular and weakly convex on inner surface, left paramere sickleshaped, groove to accommodate aedeagus open the entire length ( Fig. 5F ). Posterior margin of pygophore biconvex, with shallow folded groove left of centre ( Fig. 5F ).

FEMALE PARAGENITALIA. Paragenital guide formed by faint groove on surface of recurved right metepimeron and shallow ( Fig. 5E ), weakly sclerotized depression on anterolateral margin of abdomen; mating scars sometimes visible in dissected specimens.

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 first 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.

C. norfolkensis sp. nov. is the only Australian species known to exhibit visible external female paragenitalia. In other Australian endemic species ( C. chenopoderis Tatarnic & Cassis, 2008 ; C. monotocopsis Tatarnic & Cassis, 2008 ; C. pilbarensis Tatarnic & Cassis, 2008 ), females exhibit no discernable paragenital modifications, and mating scars are seldom visible.

Figures

Fig. 5. Photographs and scanning electron micrographs of Coridromius norfolkensis sp. nov. A. Lateral view, ♂. B. Head and pronotum, anterior view, ♂. C. Photograph of C. norfolkensis sp. nov. (sex unknown) on Schinus terebinthifolius, showing alternate scutellum colouration. D. Dorsal habitus, ♂. E. Metathorax and anterior of abdomen, lateral view, ♀, arrow indicates site of insemination. F. ♂ genitalia, posterior view. FG = folded groove of pygophore, LP = left paramere, MET = metepimeral lobe, RP = right paramere.