Redescription and generic placement of Neopamera mumfordi (Van Duzee, 1935) and Remaudiereana castanea (Van Duzee, 1935) (Hemiptera: Heteroptera: Lygaeoidea: Rhyparochromidae)

A new genus, Neocnemodus gen. nov., is erected to accommodate Neopamera mumfordi (Van Duzee) from the Marquesas Islands; the species is redescribed and illustrated, and its relationships with the genera Cnemodus Herrich-Schaeffer and Andercnemodus Brailovsky & Cervantes-Peredo are analysed. Another Marquesas Island myodochine species, Remaudiereana castanea (Van Duzee), is redescribed, illustrated, and its generic placement discussed.


Introduction
The worldwide distributed Myodochini is among the most diverse of the 14 tribes of Rhyparochromidae (Dellapé & Henry 2010). The tribe is more diverse in the Neotropical Region, where about one half of the genera occur. Only six genera are known from the Pacific Oceanic islands: Remaudiereana Hoberlandt, Pamerarma Malipatil, Paromius Fieber, Gyndes Stål, Pseudopachybrachius Malipatil, and Horridipamera Malipatil (Harrington 1980). Van Duzee (1932) described Ptochiomera caeca in "New Hemiptera Heteroptera from the Marquesas," and stated that at first he considered it a brachypterous form of Ptochiomera castanea, which he described in the same paper: "At first I was inclined to consider this a brachypterous form of castanea." Van Duzee (1935) proposed Ptochiomera mumfordi as a replacement name for P. caeca, as this was preoccupied. Scudder (1970) transferred both species to Pachybrachius Hahn without any explanation. Harrington (1980) raised from synonymy the genus Remaudiereana Hoberlandt (synonymized with Pachybrachius by Malipatil, 1978) and included 18 species, including P. castanea. In the same paper, the related P. mumfordi was transferred from Pachybrachius to the newly described genus Neopamera, and thus P. mumfordi was the only non-American species. Neopamera has been lately proven to be a highly polyphyletic genus (Dellapé 2005(Dellapé , 2008.
In this contribution we provide an illustrated redescription of the species N. mumfordi, with the view to provide detailed justification for its placement in a new monotypic genus Neocnemodus gen. nov. A description of the genus, along with notes on its comparison with other related genera, Cnemodus Herrich-Schaeffer and Andercnemodus Brailovsky & Cervantes-Peredo, is provided.
Additionally, a redescription and illustrations of another Marquesas Island species, Remaudiereana castanea, and a discussion on its systematic position is given.

Materials and methods
Composite automontage images of all habitus and other details of the body and genitalia characters were obtained with a M205C Leica microscope and camera using the Leica Application Suite software (version 3.4.0).
The specimens studied belong to the Bishop Museum, Honololu, USA (BPBM). Measurements are in millimetres.
Diagnosis: This genus can be distinguished from other genera with species exhibiting coleopteroid forms and lacking ocelli, such as Cnemodus and Andercnemodus, by its rather broad V-shaped pronotal collar, the strongly punctate body, and the scalloping of abdominal sterna; and from the former genus by the reduced evaporative area and the forefemoral spines reduced and arranged in single inner row; and from Andercnemodus by the enclosed mesepimeron, and the non-crenate corial margin.

Description:
Head (Figs. 1-3) lacking ocelli; bucculae gradually narrowed posterior and joined in a broad "V" at about 1/3 from base of head ( Fig. 4), then as fine indistinct carina extending to base of head.

Discussion:
In the key to the genera of Myodochini by Harrington (1980), this genus, because it lacks ocelli, runs to couplet 6 with Cnemodus (with two Nearctic species), and also resembles the recently described monotypic Andercnemodus (Mexico) (Brailovsky & Cervantes-Peredo 2011). These three genera share a combination of characters which are related to brachypterous, possibly flightless, morphs: absence of ocelli, and the reduction of the hemelytra and the membrane to variable degree; and a V-shaped buccula. Additionally, this genus shares with Andercnemodus the reduced profemoral armature, with only a few minute spines on its distal ½ length, and the reduced evaporative area of the metathoracic scent gland; and with Cnemodus in its enclosed mesepimeron and the non-crenate margin of the corium.
According to Harrington (1980), the strongly punctate pronotum, hemelytra, and thoracic pleura, and the scalloping of abdominal sterna, are indicative of a primitive taxon.
The above mentioned characters together with the peculiar median broad V-shaped pronotal collar (only Paromius exhibits a similar condition); the flattened pronotum, and the keeled sterna, enable distinguishing this genus from the others.
Since many of the generic diagnostic characters in Myodochini are based on males, the female holotype, the only known specimen available, does not allow us to make a robust generic characterization. Only future studies, when more specimens, particularly of males, become available, will be able to provide a detailed analysis of the relationships of these myodochine taxa.

Comments:
The female holotype is the only specimen known. Distribution. Known only from Marquesas Islands.

Comments about the systematic placement of Remaudiereana castanea (Van Duzee)
The specimen lacks the large spine at the midlength on the curved male protibiae, mentioned as diagnostic to the genus by Harrington (1980). Traditionally the presence or absence of spines on the protibiae of males was considered a distinctive character at the generic level, although intrageneric variation was reported in the genera Ashlockobius Slater & Slater (Dellapé, 2003;Dellapé & Montemayor, 2011) and Paisana Dellapé (Dellapé 2008). Malipatil (1978) noted an intraspecific variation for R. puberula with a male protibiae straight and unarmed, occasionally shallowly curved in the middle, and armed with 1-4 tuberculate, minute, irregularly spaced spines on the distal half. Despite lack of a large spine at midlength on the curved male protibiae, mentioned as diagnostic to the genus by Harrington (1980), this species was placed in Remaudiereana by Harrington (1980). The morphology of the male genitalia is very similar to R. puberula (China), as illustrated by Malipatil (1978). The similarities in the morphology of male genitalia in several species of Remaudiereana Hoberlandt that have male foretibia either armed with one spine or unarmed, suggest that this character is variable within the genus (Malipatil, 1978).
The almost glabrous body surface of R. castanea is the most conspicuous character to separate it from R. puberula, which exhibits abundant pilosity.