CORIDROMIINI, Tatarnic & Cassis, 2012

Tatarnic, Nikolai J. & Cassis, Gerasimos, 2012, The Halticini of the world (Insecta: Heteroptera: Miridae: Orthotylinae): generic reclassification, phylogeny, and host plant associations, Zoological Journal of the Linnean Society 164 (3), pp. 558-658 : 565-566

CORIDROMIINI NEW TRIBE

Type genus: Coridromius Montrouzier.

Type species: Ocypus variegatus Montrouzier, 1861 (monotypy).

Ocypus Montrouzier, 1861: 67 , junior homonym of Ocypus Leach, 1819 (Coleoptera) .

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 & Gross, 1995: 185 [Australian catalogue (cat.); transferred to Halticini ]; Schuh, 1995: 46 (world cat.; Halticini ); Liu & Zhao, 1999: 55; Miyamoto & Yasunaga, 1999: 33 (descr.); Chérot, Konstantinov & Yasunaga, 2004: 57 (descr.).

Coridromoides Carvalho, 1956: 54 (gen. nov.; type species: Coridromoides carinatus Carvalho, 1956 , by original designation); Tatarnic & Cassis, 2008: 1 (descr.; generic revision).

Diagnosis: Readily distinguished from all other Miridae by the following characters: male with hypodermic genitalia formed by the coupling of the left paramere and the aedeagus; female genitalia extremely reduced, with subgenital plate absent, vulvar region unsclerotized and symmetrical, posterior wall simple and lacking medial area and interramal lobes. Additionally, body short and squat, metafemora greatly swollen and modified for jumping, hemelytra strongly deflected at cuneus.

Diversity and distribution: Coridromius currently includes 33 species found throughout the Old World tropics and subtropics, with the Australian species Coridromius chenopoderis Tatarnic & Cassis introduced to Hawaii, south-western USA, and northern Mexico ( Tatarnic & Cassis, 2008).

Remarks: In our analysis Coridromius does not fall within the Halticini . This is unsurprising, as it lacks many of the characteristics typical of the tribe: elongate bases to both parameres, a spoon-shaped right paramere, mostly black coloration, the aedeagus with a well-developed endosoma (but see Halticus ), the ductus seminis with sclerotized ribbing and sclerotized secondary gonopore, and well-developed sclerotized rings with upturned lateral margins. Indeed, most genitalic characters in Coridromius are unlike those of any Halticini (or any other mirid): the female genitalia are highly reduced with the sclerotized rings completely absent, and in the male the aedeagus and left paramere are coupled to form a piercing intromittent organ.

Coridromius is the only plant bug genus known to practice traumatic insemination, whereby males use hypodermic genitalia to stab females in the abdomen during mating, completely bypassing the female genital tract ( Tatarnic et al., 2006). As a result, females have extremely reduced genitalia, with some species exhibiting various paragenital modifications at the site of insemination, believed to reduce matinginduced costs ( Tatarnic et al., 2006, Tatarnic & Cassis 2010). Because of this, the use of genitalic traits – in particular genital reduction or simplification – should not be taken as evidence of common ancestry.

We believe that Coridromius is sufficiently different from all other Halticini (as well as all other existing tribes within the Orthotylinae ) to justify the erection of its own monotypic tribe. Ultimately its relationship to other tribes of Orthotylinae should not be determined through morphology alone, but will instead necessitate inclusion of other data (i.e. DNA).

A thorough revision of the genus can be found in Tatarnic & Cassis (2008).