Eurystethus rufodorsatus, Correia & Fernandes & Campos, 2021

Correia, André Oliveira, Fernandes, José Antônio Marin & Campos, Luiz Alexandre, 2021, Three new species of Eurystethus from Brazil (Hemiptera: Heteroptera: Pentatomidae), Zootaxa 4958 (1), pp. 585-594 : 590-592

Eurystethus rufodorsatus sp. nov.

( Figs. 1E, F ; 2E, F ; 3J ; 4 )

Etymology. The name refers to the reddish marks on the dorsal surface. Latin: rufus, red, reddish; dorsum, back, dorsal; adjective.

Holotype female. BRAZIL. Mato Grosso. ♀, [Vera], Vila Vera, 55º 30’’ long., 12º 46’’ lat., X.1973; M. Alvarenga. [lat. -12.629081; long. -55.359544] ( AMNH).

Differential diagnosis. Dorsal surface of body with variegate and dense punctured spots, interspersed with dense reddish marks except on coria, and connexiva that look lighter than the rest of thorax are remarkable characteristics of E. rufodorsatus , unique among all other Eurystethus . Head as long as wide; pronotum with anterolateral margins arcuate and projected, and anterolateral angles anterolaterally directed ( Fig. 2E ) differs E. rufodorsatus from the other new species E. jo and E. multipunctatus , both with head longer than wide, anterolateral margins slightly arcuate, and anterolateral angles laterad.Considering the female genital plates ( Fig. 3J ), valvifers VIII subtrapezoidal, laterotergites VIII with a short fold at inner margins, and laterotergites IX subelliptical, surpassing the mediotergite VIII, are the differences between the females of this species and E. multipunctatus , with valvifers VIII acuminate, laterotergites IX rounded and barely reaching the mediotergite XIII.

Description. Head: Mandibular plates slightly reflexed. Anteocular angles developed, rounded, punctured and shorter than half the width of the eyes ( Fig. 2E ). Interommatidial sensilla short.Area behind the eyes with broad black line extending ventrally till the base of head ( Fig. 2F ). Ventral surface of head with dense punctures heterogeneously distributed, mostly on posterior half. Maxillary plates margins black on posterior half. Antennomeres proportions: I>II<III<IV; V not observed. Antennomere I almost entirely black, except on dorsal side and ventrally at base. Labial segment I laterally black at apex. Intercalary labial unit short, enlarged (sensu Ruckes 1966).

Thorax: Pronotum with anterolateral angles unpunctured ( Fig. 2E ). Transhumeral tubercles developed, conical ( Fig. 2E ). Anterior tubercles of scutellum developed, surpassing the height of transhumeral tubercles in lateral view ( Fig. 2F ). Posterior tubercle slightly developed ( Fig. 2F ). Apex of scutellum reflexed, as high as posterior tubercle in lateral view ( Fig. 2F ). Coria with thin punctures heterogeneously distributed. Lateral portions of thoracic pleura with dense punctured spots, mostly on propleuron. Mesosternum dark. Legs with dense reddish marks. Femora with few black spots heterogeneously distributed near apices. Tibiae reddish on base, yellow on apices. Tarsi yellow.

Abdomen: Connexival segments with reddish and dark brown punctured spots heterogeneously distributed, mostly on anterior and posterior margins. Urosternites with sparse spots. Intersegmental areas and pseudosutures brown, trichobothrial tubercles and spiracles black.

Female ( Fig. 3J ): Sutural angles of valvifers VIII contiguous and black; dense dark spots heterogeneously distributed on disc; sutural margins black, contiguous. Posterior margin of laterotergites VIII rounded; black spots on basal half of disc; laterotergites VIII longer and wider than valvifers VIII; inner margins with a short fold partially covered by valvifers VIII. Laterotergites IX divergent from base, small, almost entirely black, margins yellow.

Measurements. Total length: 9.6 mm; abdominal width: 6.3 mm; head length: 1.8 mm; head width: 1.8 mm; antennomeres length: I, 0.8; II, 0.6; III, 0.9; IV, 0.8 mm; pronotum length: 2.5 mm; pronotum width: 5.7 mm; scutellum length: 4.31 mm; scutellum basal width: 3.41 mm.

Distribution ( Fig. 4 ). BRAZIL. Mato Grosso: Vera.

Comments. Ruckes (1966) distinguished Hispidisoma from the nominotypical subgenus by the setigerous dorsal surface of the body and eyes, the developed anteocular processes of head, the developed anterolateral angles of pronotum, and the conspicuous intercalary unit between the labial segments I and II. When studying specimens of several species of Eurystethus for this work we observed that most of them have variations that fit with both subgenera or do not fit with any, mostly the forms of the intercalary labial unit, the presence and distribution of interommatidial sensilla which could be lost by several methods including during preparation and curation of specimens. For these reasons, we chose not to classify the new species into the subgenera, and we are preparing a review of Eurystethus to properly address this issue.

Figures

FIGURE 1. Dorsal and ventral habitus of the new species of Eurystethus. A–B, Eurystethus jo sp. nov.; C–D, Eurystethus multipunctatus sp. nov.; E–F, Eurystethus rufodorsatus sp. nov.

FIGURE 2. Dorsal view of head and pronotum, and lateral view of the new species of Eurystethus. A–B, E. jo sp. nov.; C–D, E. multipunctatus sp. nov.; E–F, E. rufodorsatus sp. nov. abe—area behind the eyes; ala—anterolateral angle of pronotum; aoa— anteocular angle; aps—apex of scutellum; ats—anterior tubercles of scutellum; ios—interommatidial sensilla; pts—posterior tubercle of scutellum; tht—transhumeral tubercles, from I to VI.

FIGURE 3. Male pygophore and female genital plates of the new species of Eurystethus. A–D, Pygophore of E. jo sp. nov.: A) dorsal, B) ventral, C) posterior and D) posteroventral; E–H, Pygophore of E. multipunctatus sp. nov.: E) dorsal, F) ventral, G) posterior and H) posteroventral; I) Female genital plates of E. multipunctatus sp. nov.; J) Female genital plates of E. rufodorsatus sp. nov. laIX—laterotergites IX; laVIII—laterotergites VIII; pa—parameres; pla—posterolateral angles of pygophore; pvr—process of ventral rim; vfVIII—valvifers VIII; vm—ventral margin of pygophore; X—segment X of pygophore; white arrow—indicates the projections of process of ventral rim in ventral view; red arrow—indicates the dorsal projection at base of posterolateral angle.

FIGURE 4. Distribution map of the new species of Eurystethus in Brazil.