Revisional notes on the genus Melucha (Hemiptera, Heteroptera, Coreidae)

Melucha grandicula sp. n. and M. perampla sp. n., (Hemiptera: Heteroptera: Coreidae: Coreinae: Nematopodini) are described from Bolivia, Colombia, Paraguay and Peru. Melucha quadrivittis Stål, 1862, stat. restit., is resurrected from synonymy under M. phyllocnemis (Burmeister, 1835). Melucha ruficornis Breddin, 1903, syn. n., is synonymized under M. lineatella (Fabricius, 1803). An identification key for the known species of Melucha Amyot & Serville, 1843 is given. New distributional records for some previously known species are added.


Introduction
The genus Melucha Amyot & Serville, 1843, is distributed in Mexico, Central America (Guatemala, Costa Rica) and South America (Colombia, French Guiana, Brazil, Paraguay, Bolivia, Peru).It belongs to the tribe Nematopodini of the family Coreidae and is characterized by having: postocular tubercles not evident, forming a smooth curve with eye; antenniferous tubercles wide, not projecting far anteriorly; tylus projecting anteriorly of antenniferous tubercle; antennal segment I longer than length of head, thicker than following segments and curved; segment II cylindrical, III cylindrical or dilated, and IV fusiform; anterolateral and posterolateral borders of pronotal disk smooth or conspicuously nodulose and spinate; mesosternum lacking sulcation; and abdominal spiracles rather large, transversely elliptical, situated nearer to anterior than to lateral margins (O 'Shea 1980).

Material and methods
The following collection acronyms are used for the institutions cited in this paper: Description (female, holotype).Dorsal color.Head and antennal segments I to III shiny orange, segment IV pale yellowish orange; pronotum coarsely punctate, strongly striate, reddish brown, with a single, longitudinal, median dark line, diffuse, with pigment in the punctures; scutellum reddish brown with basal third, lateral borders and apex shiny orange; clavus and corium finely punctate, reddish brown, moderately infuscate; hemelytral membrane amber, translucent, veins darker; connexival segments reddish brown with posterior spines black; dorsal abdominal segments dark orange with irregular dark marks.
Ventral color.Rostral segments (apex of IV dark brown), legs, and anterior and posterior lobe of metathoracic scent gland peritreme shiny to dull orange; pro-and mesopleura coarsely punctate with black elongate mark; hind femur dull orange with dorsal and ventral tubercles and spines black; hind tibiae dark orange with posterior third yellowish orange; middle and hind tarsus yellowish orange.
Legs.Fore and middle femora not incrassate; dorsal surface smooth, ventral surface distally armed; hind femur incrassate its dorsal surface with two rows of tubercles, ventral surface armed with two rows of spines increasing in size distally; fore and middle tibiae sub-cylindrical, unarmed, sulcate; inner and outer surfaces of hind tibiae markedly dilated; outer surface smooth, inner surface with short tubercles on the border.
Scutellum.Differential diagnosis.This species is closely related to M. phyllocnemis and M. quadrivittis, which are also robust and larger than 23.00 mm; the other species in the genus are slender and shorter than 20.00 mm.
Etymology.Named for the comparatively large size of this species, after the Latin adjective "grandiculus, -a, -um" meaning rather large.
Distribution.Known from Colombia and Peru.
Melucha perampla sp.n.Description (female, holotype).Dorsal color.Head yellow; preocular area and two short, diffuse stripes laterally to midline pale brown; antennal segments I to III black, IV yellow; pronotum finely punctate, yellow, pronotal disk with four longitudinal dark brown lines with pigment in the punctures and midline unpigmented; anterolateral spines of pronotum reddish brown; scutellar disk yellow with punctures reddish brown; clavus and corium dark yellow with punctures reddish brown; hemelytral membrane dark amber, veins brown and darker; connexival segments III to V dark brown with anterior third yellow, VI-VII with anterior half yellow and posterior half dark brown, and VIII--IX yellowish orange; upper border of connexivum anteriorly yellow and posteriorly black; posterolateral spines black; dorsal abdominal segments dark yellow with irregular dark brown marks.
Ventral color.Rostral segments (apex of IV dark brown), legs, anterior and posterior lobe of metathoracic scent gland peritreme and abdominal sterna yellow; hind femur yellow with ventral spines and apical border reddish brown to black; hind tibia yellowish orange, posterior third yellow with dark reddish brown transverse mark near posterior third.
Legs.Fore and middle femora not incrassate their dorsal surface smooth, ventral surface distally armed; hind femur incrassate its dorsal surface smooth, ventral surface armed with two rows of spines increasing in size distally; fore and middle tibiae sub-cylindrical, unarmed, sulcate; inner and outer surface of hind tibiae markedly dilated; outer surface smooth, inner surface with short tubercles on the border.
Scutellum.Melucha perampla differs by having the antennal segments I to III black, antennal segment III clearly dilated at inner and outer faces and mesopleura and metapleura without black marks.In the other two species the antennal segments I to III are yellowish orange, antennal segment III is almost cylidrical, not dilated and mesopleura and metapleura have reddish brown to black elongate marks.The dorsal surface of the hind femur of M. quadrivittis is armed with two rows of black nodules and tubercles (Fig. 8) while in M. phyllocnemis and M. perampla those are smooth (Figs. 9,12).
Etymology.Named for the large size of this species, after the Latin adjective "peramplus, -a,-um", meaning very large.
Distribution.Known from Bolivia and Paraguay.
In M. quadrivittis the dorsal surface of hind femur is armed with two rows of black nodules and tubercles; it is distributed from Mexico to Panama (Fig. 8).In M. phyllocnemis the dorsal surface of hind femur is smooth.It is distributed from Colombia to Paraguay, including Bolivia and Brazil (Fig. 9).

Results Melucha grandicula sp. n.
Triangular, wider than long, transversely striate and punctate; apex subacute.Abdomen.Posterior angle of abdominal segments III to VI armed with short but distinct spine.
Triangular, longer than wide, transversely striate, punctate; apex subacute.Abdomen.Posterior angle of abdominal segments III to VII armed with short but distinct spine.Like M. phyllocnemis and M. quadrivittis, the humeral angles of M. perampla sp.nov., are prominent, laterally expanded and apically blunt; the pronotal disk has four longitudinal dark brown lines with the midline unpigmented; total body length over 20 mm.