Moncus hoplita, Breddin, 1912

Campos, Luiz Alexandre & Roell, Talita, 2017, Melambyrsus hoplita Breddin rediscovered (Hemiptera: Pentatomidae: Discocephalinae): redescription of genus and species, Zootaxa 4286 (1), pp. 134-138 : 136-138

Melambyrsus hoplita Breddin, 1912

Melambyrsus hoplita Breddin, 1912: 91 –92; Rolston, 1992: 2.

Holotype female ( Figs 1–3 , examined), deposited in the Senckenberg Deutsches Entomologisches Institut at Müncheberg, Germany. Labels ( Fig. 2 A): Cauca, Colomb. ; coll. Breddin; DEI Müncheberg Hemi - 0 0 0 38. Labels added: HOLOTYPE Melambyrsus hoplita Breddin, 1912 .

Type locality. Uncertain. Although in the original description Peru is referred to as the type locality of M. hoplita ( Breddin 1912: 92) , the labels accompanying the specimen indicates Cauca in Colombia as the collection site.

Redescription. Large body, brown; scutellum ample with a yellow spot on the middle of anterior margin. Head with confluent punctures forming wrinkles on vertex, clypeus, and mandibular plates, denser on the base of mandibular plates, absent on apex. Mandibular plates and clypeus subequal in length ( Figs 1 A, 3C). Width of each eye less than half of the interocular width. Ocelli red; antenniferal tubercles visible from above with acute lateral margins. Labium long, reaching the fifth abdominal segment, proportion labium segments: I<II>III>IV.

Pronotum ( Figs 1 A, 3C) with sparse punctures and thin wrinkles near the posterior margin; cicatrices flat, without punctures; anterior margin concave medially; anterolateral margins smooth, concave, and reflexed along the surface; anterolateral margins expanded sub apically in 1+1 acute angles directed anterolaterally and surpassing the lateral margins of eyes; humeral angles not produced.

Scutellum ( Fig. 1 A) apex obtuse, reaching a transversal imaginary line at the posterior angles of abdominal sternite VI. Punctures thin and sparse on disc; one yellow irregular spot on the middle of anterior margin. Corium reaching connexival segment VI, punctures denser than scutellum and pronotum; membrane short, not attaining urotergite VIII. Evaporatorium black, with rare punctures; peritreme copperish brown ( Figs 1 B–C, 2B). Connexivum exposed from segment III to VII. Abdomen ( Figs 1 B–C) thinly punctured, spiracles black.

Measurements. (n=1): head length 2.88, width 3.28; interocular distance 1.86; pronotum length 3.84, width 6.31; scutellum length 6.31, width 4.54; length of antennomeres: I 1.24; length of labium segments: I 1.52, II 2.56; III 2.20, IV 1.92; length of abdomen 7.00, width 8.7; total length 14.04.

Genitalia ( Fig. 2 C–D). Laterotergites VIII wider than long, posterior margins almost straight. Gonocoxites VIII hook-like, narrowing towards the apex, expanded posterolaterally in digitiform projection over the limits between laterotergites VIII and IX, almost reaching the apical limit of laterotergites IX. Gonocoxites IX exposed, with a lozengeshaped median portion strongly sclerotized and bearing a wide, shallow, median depression; gonapophyses IX exposed laterally to gonocoxites IX, sclerotized. Laterotergites IX ample, oval, not reaching the band uniting laterotergites VIII.

Comments. Breddin’s description of the bizarre gonocoxites VIII of Melambyrsus is very detailed, leaving no doubt about the identity of the type specimen: “Basiplatten des 8 (♀) Abdominalsegments groß, einen langen, sichelähnlichen Fortsatz nach der Afteröffnung zu entsendend, der die Inzisur zwischen dem 8 sternit und dem 9 sternit bedeckt, und der das 9 sternit vorn, außen und teilweis auch hinten umfaßt.” ( Breddin, 1912: 91). This can be translated as: the basal plates [= gonocoxites] of the abdominal segment eight (♀) are large, forming a hook-like extension beyond the anal opening, covering the incision between the sternites [= laterotergites] eight and nine, and enfolding laterally and partially behind the ninth sternite.

Melambyrsus has several similar features with those ochlerine genera bearing a somewhat triangular head and large scutellum, identified as the Orbatina Ruckes group in the phylogeny of Ochlerini by Campos & Grazia (2006). Within the Orbatina group only Moncus Stål , Stalius Rolston , and Ochlerus handlirschii Breddin present the scutellum longer than coria as seen in Melambyrsus. Despite the long scutellum, of all the genera in the Orbatina group (i.e. Coranda Rolston, Moncus , Ochlerus, Orbatina , Parastalius Matesco, Grazia & Campos , Schraderiellus Rider , and Stalius ) Melambyrsus and Orbatina show a similar structure of the head, with the mandibular plates more rounded at apex, the gonocoxites VIII posteriorly projected on midline, and gonocoxites IX with a mesial excavation. Melambyrsus can be readily distinguished from Orbatina by the longer scutellum, the head and pronotum subequal in length (in Orbatina the head equals 0.71 of pronotum) ( Fig. 3 C–D), and the round anterior margin of bucculae (angulate in Orbatina) ( Fig. 3 A–B). Melambyrsus is also distinguished from all genera in the Orbatina group by the large laterotergites IX, the projection of gonocoxites VIII between the laterotergites VIII and IX, and the partially exposed gonapophyses IX.

Figures

FIGURE 1. Melambyrsus hoplita Breddin, holotype female. A, dorsal; B, ventral; C, lateral views. Scale bar = 1 mm.

FIGURE 2. Melambyrsus hoplita Breddin, holotype female. A, labels accompanying the specimen. B, left evaporatorium and peritreme, ventrolateral view. C, D, genital plates, lateral and posterior views respectively. Abbreviations: g 9, gonapophyses IX; gc 8, gonocoxites VIII; gc 9, gonocoxites IX; la 8, laterotergites VIII; la 9, laterotergites IX. Scale bars = 1 mm.

FIGURE 3. Comparison between the head and pronotum of Melambyrsus hoplita Breddin and Orbatina fuligina Ruckes. A, B, head, lateral view, M. hoplita holotype female and O. fuligina holotype male respectively. C, D, head and pronotum, dorsal plane of the head, M. hoplita holotype female and O. fuligina allotype female respectively. Abbreviation: b, buccula. Scale bars = 1 mm.