Coridromius Signoret

Tatarnic, N. J. & Cassis, G., 2008, Revision Of The Plant Bug Genus Coridromius Signoret (Insecta: Heteroptera: Miridae), Bulletin of the American Museum of Natural History 2008 (315), pp. 1-95 : 20-25

Coridromius Signoret

Ocypus Montrouzier, 1861: 67 , junior homonym of Ocypus Leach , in Samouelle, 1819: 172 ( Coleoptera ). Type species: Ocypus variegatus Montrouzier, 1861 , by monotypy.

Coridromius Signoret, 1862: 5 (nom. nov. for Ocypus Montrouzier 1861 ).

Neocypus Distant, 1914: 378 (unnecessary nom. nov. for Ocypus Montrouzier, 1861 ). Carvalho, 1987: 61; Linnavuori, 1994: 15; Schuh, 1995: 46; Cassis and Gross, 1995: 185; Liu and Zhao, 1999: 55; Miyamoto and Yasunaga, 1999: 33; Chérot et al., 2004: 57.

Coridromoides Carvalho, 1956: 54 (new genus). Type species: Coridromoides carinatus Carvalho, 1956 , by original designation.

DIAGNOSIS: Coridromius is recognized by the following character states: body compact and stout (figs. 1–5); small, with most species between 2–3 mm in length (table 1); short and broad head with substylate eyes (figs. 4– 6); hemelytra sharply deflected at cuneal fracture; greatly enlarged metafemora, frequently marked with dark brown diagonal banding (figs. 1–3); femora with recessed bothria; aedeagus simple, membranous, without sclerotizations (figs. 12A, 17A); left paramere larger than right and generally scythe-shaped, with gutter running from base to apex, coupled with aedeagus to form piercing intromittent organ (figs. 12A, 17A); right paramere smaller than left, triangulate to club-shaped, sometimes with short and rounded (e.g., figs. 10B–C, 10G–H) or long and sharp (e.g., figs. 7O–P) apical process; female genitalia reduced, with the posterior wall entirely membranous (fig. 20A); female paragenitalia sometimes present (figs., 8C–D, 9C–D, 11C–D, 11G–H, 13A–B, 13D–F, 16C–D, 18F–G, 19B–C, 19G, 20B–C, 21A). Coridromius is readily distinguished from all other Halticini (and all other Miridae ) by its unique male genitalia.

REDESCRIPTION: COLORATION: Variable, but typically brown with various brown, yellow, and cream-colored markings; frequently with dark brown vittae on frons and transverse stripes on outer surface of metafemur (e.g., figs. 1–3). SURFACE AND VESTITURE: Head, pronotum, scutellum, propleuron, metepimeron, and hemelytra impunctate to punctate; broadly covered with short or long simple, white, decumbent setae. STRUCTURE: Head (fig. 6): Transverse, short; eyes substylate; frons tumescent medially, shallowly depressed adjacent to eyes; vertex usually with a pair of slightly raised tubercles adjacent to eyes, bordered posteriorly by shallow foveae; posterior margin of head weakly to strongly medially rounded; mandibular and maxillary plates well defined; gena sometimes swollen; clypeus prominent; buccula arcuate and flared; labium reaching slightly beyond hind coxae. Antenna: AI very short and cylindrical (approximately five times shorter than width of vertex); AII about one-fifth longer than AI and apically clavate; AIII short, about twice as long as AI; AIV about as long as AI (table 1). Thorax: Pronotum broad and convex, anterolateral margins usually somewhat upturned, submarginal region of humeral angles shallowly excavate, collar present and rounded, visible from above, callar region either undifferentiated or weakly defined, lateral margins sometimes carinate; mesoscutum steeply declivent, sometimes visible, scutellum flat or swollen and round- ed, sometimes with rounded lobe at apex (e.g., fig. 1D); proepisternum lobate, with either one (figs. 3C, 13C) or two (figs. 3C, 18A) lobes projecting laterally; metathoracic spiracle prominent; metepimeron platelike, with posterior margin either truncate (e.g., figs. 8E, 11C) or extending partly over abdomen (e.g., figs. 9E–F, 11G–H, 13E–F); metanotum sometimes raised into a vertical transverse plate separating thorax from abdomen, with lateral margins prominent and flared (figs. 9C–D, 16C–D). Metathoracic gland: External efferent system reduced, peritreme elongate, fingerlike, along posteri- or margin of metepisternum, bounded anteriorly by a thin strip of evaporative bodies. Hemelytra: Macropterous; steeply declivent at cuneal fracture; embolium thin and platelike, sometimes flared; cuneus small and triangular. Legs: Metafemur swollen, laterally compressed near apex; caudal margin of hind tibia with two rows of minute spines interspersed with longer spines, sometimes noticeably thickened (fig. 3A). MALE GENITALIA: Pygophore trapeziform, posterior margin typically biconcave, sometimes with fold (figs. 8A, 8H, 14D, 16A, 21C–D), groove (figs. 11E–F, 14G–H, 19H) or mesal suture on left side (figs. 9A, 9H, 11A, 13H, 14F, 16E, 19D, 21A), sometimes with ventral apical process projecting from right side (figs. 9A, 9G–H, 11A, 13H, 14E–F, 16A– B, 16E, 18D, 19D); parameres heavily sclerotized; right paramere always smaller than left, usually either triangular and somewhat elongate (figs. 7B–C, 7E–G, 7L–M, 10J, 12B–C, 12E–F 12K–L, 12O–P, 15B–C, 17B–D, 17M–O, 17Q–R), boot-shaped (figs. 7I–J, 15H–I), or club-shaped with a long, spinelike (figs. 7O–P, 7R–S, 12N–O, 17F–G) or short and more rounded (figs. 10B–D, 10F–H, 15E–F, 17B–D, 17P–Q) apical process; left paramere generally curved and scythelike, sometimes with one to several tight coils (e.g., figs. 7H, 8F, 17H, 17S, 19E– F, 21D), apically acuminate, with cleft gutter running entire length, sometimes completely enclosed until apex (figs. 7Q, 9G–H, 15D, 14E–F); aedeagus simple, flagellate, with membranous to weakly sclerotized phallotheca and phallobase, permanently routed through channel of left paramere (e.g., fig. 17A). FEMALE GENITALIA: Simple and reduced, with posterior wall membranous, interramal lobes absent (e.g., fig. 20A); abdomen sometimes with visible external paragenital modifications.

REMARKS: The genus Coridromius is easily recognized by the unique body shape, extremely swollen hind femora and highly specialized male genitalia. While several species are easily identifiable by coloration and body shape, others are sometimes more difficult to place. For most species the male genitalia can typically be examined in situ, but often one must remove female specimens from points or remove the hemelytra in order to expose possible paragenital modifications, which have always been found on the right side of the abdomen. The following key is intended to be used with both sexes, except in those species that are known by one sex.