Plinachtus melinus, Brailovsky, Harry, 2007

Brailovsky, Harry, 2007, A revision of the tribe Gonocerini from Australia (Hemiptera: Heteroptera: Coreidae: Coreinae), Zootaxa 1530, pp. 1-18 : 15-17

Plinachtus melinus n. sp.

( Figs. 1, 3, 18 , 28 )

Description. Holotype male. Head length 1.52; width across eyes 1.68; interocular space 0.90; interocellar space 0.42; preocular distance 0.96; antennal segment length I, 1.90, II, 2.48, III, 1.74, IV 1.60; pronotum length 2.32; width across humeral angles 3.76; scutellar length 1.32; width 1.36; maximum width of abdomen 3.40; total body length 11.10. Dorsal coloration.— Head and pronotum pale yellowish orange with following areas black to reddish brown: two longitudinal stripes on either side of midline and near eyes, ocellar tubercle, space between antenniferous tubercles and eyes, inner face of postocular tubercle, anterolateral margins of pronotum, humeral projection, a few punctures at posterior lobe of pronotal disk; antennal segments I to III shiny orange, IV dark brown but basally and apically paler; scutellum pale yellowish orange, punctures pale reddish brown, apex pale brown; clavus pale yellowish orange, punctures pale reddish brown; corium pale yellowish orange, punctures pale reddish brown, apical margin and apical angle reddish, anterior 2/3 of costal margin with pale yellow longitudinal stripe, narrow basally and widened apically; hemelytral membrane translucent, basal angle pale brown; connexival segments III to V pale yellow, VI and VII pale yellow with dark brown spot at anterior margins, occupying only inner third; dorsal abdominal segments II to VI shiny yellowish orange, VII dark reddish brown, posterior margin dark brown. Ventral coloration.— Pale yellow with small black discoidal spot on metapleuron; rostral segment I and II pale yellow, III and IV shiny orange (apex of IV dark brown). Structure.— Head.— Pentagonal, elongate, surpassing antenniferous tubercles; antenniferous tubercles unarmed; antennal segment I somewhat triquetral, stouter than others, with small denticles, slightly curved outward; antennal segment II gradually incrassate, segment III narrowly expanded, elliptical, IV fusiform ( Fig. 1); segments II>I>III>IV; rostrum reaching middle third of metasternum. Thorax.— Pronotum.— Humeral angle thick at base, humeral spine tapering, short and acute pointing outward and slightly upward ( Fig. 3). Genital capsule.— Posteroventral edge with medial lobe protruding, prominent, lateral lobes symmetrical, stout, space between them slightly concave to straight ( Fig.18 ).

Female. Head length 1.60; width across eyes 1.84; interocular space 1.02; interocellar space 0.48; preocular distance 1.02; antennal segment length I, 1.92, II, 2.60, III, 1.84, IV 1.66; pronotum length 2.60; width across humeral angles 4.12; scutellar length 1.52; width 1.56; maximum width of abdomen 3.88; total body length 12.18. Coloration similar to male holotype. Connexival segments VIII and IX pale yellow; dorsal abdominal segments II to VII shiny yellowish orange, VIII to IX shiny yellowish orange, laterally pale brown; genital plates pale yellow. Structure.— Genital plates: abdominal sternite VII as in Plinachtus refulgens . Gonocoxae I enlarged anteroposteriorly, in caudal view opened, upper third with inner margin rounded and clearly overlapping, outer margin barely convex; paratergite VIII triangular, spiracle visible; paratergite IX broad, squarish.

Variation. 1. Antennal segment IV pale orange, basal joint and apex pale yellow. 2. Mesopleuron and metapleuron with wide reddish discoidal spot. 3. Coxae, posterior third of femur, basal and apical third of tibiae, and tarsi pale reddish.

Types. Holotype male, AUSTRALIA: Queensland, Biggenden, Mt. Walsh Nat. Pk., Bluff Range 10- VIII-1971, H. Frauca (ANIC). Paratypes. AUSTRALIA: 2 females, N Queensland, Townsville, G. F. Hill (without date) (SAMA); 1 female, Queensland, Townsville, 24-III-1968 (light trap), P. Ferrar (ANIC); 1 female, Queensland, 8 mi NW of Mt. Molloy, 19-IX-1956, M. J. D. White (ANIC); 1 male, NE Queensland, McLeod River, crossing Mt. Carbine, Mt. Spurgeon Rd., 16°28’S 145°09’E, 19-XI-1997, C. J. Burnwell (QMBA).

Comments. This new species is related to P. refulgens Brailovsky in having the head elongate and surpassing the antenniferous tubercles, the later unarmed, and the abdominal sternite VII of female with the plica reduced and occupying the anterior border of the sternite, and the fissura covering most of the total length. Plinachtus melinus n. sp., is a relatively narrower and shorter species, less than 12.50 mm long; its humeral spine tapers into a short acute spine pointing outward and slightly upward ( Fig. 3); its antennal segment I is somewhat triquetral, and segment III is narrowly elliptical and expanded ( Fig. 1); the new species’ costal margin of corium has a pale yellow longitudinal stripe, narrow on the basal third and expanded apically; its rostral segments I and II are pale yellow and III and IV are shiny orange; its metapleuron have a single small black discoidal spot; and its gonocoxae I in caudal view is clearly open. Plinachtus refulgens , is a robust species, longer than 13.00 mm; humeral projection clearly longer, narrowed, acute, and directed upward ( Fig. 4); costal margin of corium without a pale yellow longitudinal stripe; antennal segment I not triquetral, and III cylindrical and not expanded ( Fig. 2); rostral segment I yellow, segment II black to pale brown, basal joint yellow, III to IV black to pale brown; metapleuron with large black discoidal spot; and gonocoxae I in caudal view closed.

Etymology. The species epithet is derived from the Latin adjective, melinus , meaning quince yellow, and referring to the yellow mark on the costal margin of the corium.

Figures

FIGURE 28. Dorsal view of Plinachtus melinus n. sp. (male).

FIGURE 17 – 22. Male genital capsule in caudal view. 17 – 18. Plinachtus spp. 17. Plinachtus refulgens n. sp. 18. Plinachtus melinus n. sp. Figure 19. Cletomorpha mackayensis Distant. 20 – 22. Cletus spp. 20. Cletus similis Blöte. 21. Cletus minutus Blöte. 22. Cletus saucius Stål.