Platystigma pronoti
Creators: name: Machado, Angelo B. M.
name: Soldati Lacerda, Déborah S.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Odonata
Pseudostigmatidae
Platystigma
Platystigma pronoti

description: Platystigma pronoti (Sj ӧstedt, 1918) n. comb.
Figures 12, 18, 33–36
Sj ӧstedt (1918: 31); Davies & Tobin (1984: 57); Garrison & Ellenrieder (2016: 20); Machado (1992: 19); Bridges (1994: 39); Tsuda (2000: 58); Machado, Drummond & Martins (2005: 96); Heckman (2008: 205); Garrison, Ellenrieder & Louton (2010: 391); Schorr & Paulson (2016); Machado & Lacerda (2016: 63).
Material examined. Holotype ♀: Brazil, Espírito Santo (no further information available). Holotype deposited in the NHMS.
Diagnosis. Head with dorsum black and orange-white spots anteriorly and another medially to antennae base. Pronotum dark brown with pair of pale yellow stripes anteriorly and laterally to middle lobe. Border of medial and apex of lateral portions of posterior prothorax lobe pale yellow. Median portion straight, separated from lateral portions by deep incision at each side (Fig. 12); lateral portions with apex rounded (Fig. 12). Mesepisternum (Fig. 18) black with antehumeral grayish-yellow stripe occupying whole extension of sclerite. Mesepimeron dark brown with grayish-yellow stripe not reaching lower part of sclerite. Metapleuron (Fig. 18) whitish yellow with black stripe adjacent to metapleural suture occupying dorsal ¾ of sclerite. Venter of pterothorax whitish yellow, with narrow middle dark stripe occupying its anterior ½. It is impossible to know whether this stripe reaches the posterior part of the venter, because it is damaged. Supplementary tooth of tarsal claws absent. Wings dominantly hyaline with apical area milky-white reaching a row of cells posterior to RP1. Pseudostigma in both wings weakly indicate pale yellow color (Figs. 33, 35). At high saturation, the color of apical area changes; the white color becomes pale blue and the pseudostigma appears very evident, yellow, with six cells in Fw and eight in Hw (Figs. 34, 36). Costal vein becomes orange and RA to RP1 yellow (Figs. 34, 36). Abdomen dominantly brown. Cercus dark, with apex rounded. Ovipositor (stylus lacking) reaching posteriorly about level of hind border of S10.
Measurements (mm): Hw 40. Abdomen 54.
Male: unknown.
Remarks. Mecistogaster pronoti is transferred here to Platystigma based on its small size, absence of supplementary tooth of tarsal claw and presence of pale apical areas on the wings. The species was described by Sj ӧstedt (1918) based on a single female specimen from the state of Espírito Santo, Brazil, and has never been found again. According to Heckman (2008), “ M. pronoti is a rare or unrecognized species.” The holotype of P. pronoti has been recently redescribed and illustrated by Machado & Lacerda (2016), thus allowing its easy identification. The main character separating P. pronoti from the other Platystigma species is the peculiar form of the hind prothoracic lobe, whose median portion is clearly separated from the lateral ones. P. pronoti has been listed as Critically Endangered in Brazil’s, Portarias MMA n o 444/445 (2014) and IUCN (2006) red list, and a strategy for its conservation has been proposed by Machado & Lacerda (2016).
Platystigma quadratum sp. nov.
Figures 13, 19, 24, 32, 41, 50, 51, 60, 61
Material examined. Holotype ♂: Brazil, Acre State, Senador Guiomard, Reserva Catuaba (10° 03' 60"S, 67° 35' 59"W), IX–2003, Mielke & Casagrande leg. (ABMM). Two ♂ paratypes with same data as holotype.
Etymology. From Latin quadratum-a-um, quadrate, an allusion to the shape of its penis segment 3 in ectal view.
Description of the male holotype. Head. Labium whitish yellow, base of mandible and genae bluish yellow, anteclypeus and postclypeus grayish blue, antefrons brownish. Upper part of head black with metallic green luster. Postocular lobe and occipital crest yellow. Rear of head whitish yellow.
Thorax. Prothorax: pronotum black. Anterior lobe with pair of pale oblong transverse spots. Middle lobe with large pale marking dilated posteriorly (Fig. 13). Posterior lobe bordered with yellow (Fig. 13). Propleuron yellow with black markings (Fig. 13). Pterothorax: mesepisternum (Fig. 19) black with middorsal carina yellow, antehumeral yellow stripe reduced to triangular marking at about 1/3 of sclerite. Posthumeral yellow stripe not reaching lower part of sclerite. Mesepimeron black. Metapleuron yellow with black stripe along metapleural suture. Venter with anterior triangular and posterior subcylindrical black spots (Fig. 24).
Wings. Fw hyaline with light brown pseudostigma, with six cells. Hw with large apical area bluish white reaching RP2; pseudostigma blue with eight cells (Fig. 32). At high saturation, bluish white area becomes whitish blue, surrounded by blue and pseudostigma more intensely blue. Venation: Px in Fw 31, in Hw 33, RP 2 in Fw and in Hw originating at Px 11. IR1 originating at Px 16 in Fw, at Px 14 in Hw. RP2 branching from RP at about half distance from subnodus to tip of wing. Petiolation originates distal to CuP by two times length of CuP in Fw and three times in Hw.
Legs. Femora with proximal 1/3 yellow, distally black on extensor surface and yellow on flexural surface. Tibiae with extensor surface yellow and flexural surface black. Tarsi black.
Abdomen. S1–10 dorsally black, laterally yellow. Cerci black.
Structural characters. Median and lateral portions of posterior prothoracic lobe not separated. Posterior border slightly convex (Fig. 13). Cleft of anterior lamina shaped as ogival Gothic arch (Fig. 41). Anterior hamuli with ear-like basal plate. Posterior hamuli with apex curved anteromedially (Fig. 41). Distal portion of batilliform lamina very small, apex sclerotized (Fig. 41). Penis segment 3 in ectal view subquadrate with small tongue-like apical lobe and tuft of spines at anterolateral angle (Fig. 50); in lateral view with medial and distal tuft of spines (Fig. 51). Penis segment 2 with large tuft of spines near commissure (Figs. 50–51). Hind border of S 10 in dorsal view with medial concavity (Fig. 60); in lateral view with distal ½ elevated (Fig. 61). Cerci in lateral view cylindrical, with distal 1/3 tapering and directed ventrally (Fig. 61). In dorsal view, distally convergent (Fig. 60).
Measurements (mm): Hw 47, abdomen 60.
Variations in paratypes. In one of the paratypes the tuft of spines at the anterolateral angle of penis segment 3 is hardly visible.
Female: unknown.
Remarks. P. quadratum shares with P. humaita the penis segment 3 subquadrate, with a small tongue-like apical lobe. It differs from it by having a pale apical area only in Hw (in both wings in P. humaita).
description: Published as part of Machado, Angelo B. M. & Soldati Lacerda, Déborah S., 2017, Revalidation of Platystigma Kennedy, 1920, with a synopsis of the quadratum species group and the description of three new species (Odonata: Pseudostigmatidae), pp. 493-516 in Zootaxa 4242 (3) on pages 501-502, DOI: 10.11646/zootaxa.4242.3.4, http://zenodo.org/record/376925