Mycterizon Breddin, 1909

Salini, Santhamma, Gracy, R. G., Akoijam, Romila, Rabbani, Mehaboob K., David, K. Jacob & Roca-Cusachs, Marcos, 2023, Revision of Acesines Stal and Dunnius Distant, resurrection of Mycterizon Breddin (Hemiptera, Heteroptera, Pentatomidae, Pentatominae), and description of a new species from India, ZooKeys 1148, pp. 79-117 : 79

Mycterizon Breddin, 1909 stat. rev.

Mycterizon Breddin, 1909: 279 (original description). Type species: Araducta bella Distant, 1900a: 427, by monotypy. Synonymized with Dunnius by Distant (1918): 145.

Redescription.

Colouration. Body ochraceous, with irregular black markings on pronotum, scutellum and hemelytra; membrane smoky brown, translucent; legs and antennae pale white; apex of labium, small, transverse line below the spiracles on either side of abdomen, small, irregular spots laterad to spiracle on either side of abdomen, anterior and posterior lateral angles of abdominal sternites III-VII, black.

Integument and vestiture. Body on dorsal side with black, coarse punctures confluent to form narrow black transverse streaks especially on pronotum, sometimes forming medium to large, irregular spots; fine punctures on connexivum. Ventral side with punctures more concentrated laterad; punctures fine and less dense medially; femora with dense, coarse punctures and tibiae with fine, black punctures. Genital capsule (ventrally) including posterolateral lobes with fine pale brown punctures; valvifers VIII and laterotergite VIII with sparse, coarse, brown punctures.

Dorsum glabrous, antennomeres I-IV and labium with short, semi-erect, dense golden setae; legs with moderately elongate golden setae; ventral side of abdomen with dense short, golden pubescence. Genital capsule (dorsal rim, posterolateral lobes and the caudal 1/2 of genital capsule on ventral side) with moderately elongate, dense, semi erect, golden setae. Female genitalia (valvifers VIII, valvifers IX, laterotergite VIII and IX) with moderately long, golden semi-erect setae.

Structure. Head above flat, as broad as 1.5 times the head length, lateral margins not reflexed, distinctly concave in front of compound eyes, outline of anterior part of head disc inverted U-shaped, beyond the concavity on lateral margins, in front of compound eyes; dorsum of head disc with transverse impression medially along the imaginary transverse line connecting the anterior margins of compound eyes and another 1+1 short, C-shaped impression adjacent to inner margins of compound eyes. Head length behind compound eyes much shorter and accommodated in the shallow median concavity of anterior margins of pronotum. Mandibular plates nearly twice as wide as width of clypeus, moderately narrowed towards apex, nearly as long as clypeus, not meeting in front of clypeus. Compound eyes protruded and stylate-like. Antennae with five antennomeres, slender; antennomere I cylindrical, shortest and stoutest, nearly reaching apex of head, remaining antennomeres cylindrical and slender. Labium short, reaching mesocoxae.

Pronotum. Anterior margin collar-like, slightly concave medially, anterior pronotal margin including the minute, laterally directed denticle, nearly as wide as head width including compound eyes. Anterolateral margin obliquely straight, not reflexed, smooth; posterior margin concave medially, posterolateral margins obliquely straight, posterolateral angles rounded; humeri rounded. Disc of pronotum strongly convex with anterior 2/3 sloping downwards.

Scutellum. Longer than broad at base; scutellar disc slightly gibbous basally; lateral margins slightly convex in frenal portion; posterior 1/2 of scutellum, beyond frena, broad and nearly U-shaped, with apex broadly rounded.

Hemelytra. Corium with anterodistal angles rounded, extending beyond apex of scutellum. Membrane translucent with seven or eight simple veins, without reticulate venation.

Thoracic pleuron and sternum. Mesosternum with median longitudinal carina uniformly narrow, not extending beyond procoxae; metasternal carina low, less developed. External scent efferent system with peritreme well developed, short, nearly reaching mid-metapleuron, spout-like, obliquely elevated to pleural surface (Fig. 65 ), the distal end of peritreme slightly raised, forming plate-like structure (unlike adjacent to pleuron), reaching middle of metapleural width.

Legs. All femora unarmed, cylindrical and rounded in cross-section. All tibiae with median longitudinal sulcation, rounded beneath. tarsi dorsally regularly rounded, tarsomere II shortest and tarsomere I and III subequal.

Pregenital abdomen. Body moderate size (8-10.45 mm long), oblong, abdomen nearly as wide as width across pronotal humeri and possesses more or less uniform width throughout. Connexivum usually not exposed. Sternites smooth, devoid of furrows or ridges; basal abdominal sternites lacking tubercle or spine or distinct groove; posterolateral angles of sternites III-VII either angulate or sometimes with short, stout, an blunt tooth.

Male genitalia. Genital capsule nearly quadrangular with posterolateral lobes well developed and broadly rounded. Dorsal rim widely and deeply excavated concave with nearly straight middle margin. Ventral rim medially shallowly excavated and broadly concave. Paramere. Sclerotised, crown broad, subquadrate. Phallotheca longer than broad, with thecal process slightly developed; four pairs of conjunctival processes; processes of aedeagus fused mid longitudinally, partially enclosing aedeagus.

Female genitalia. Valvifers VIII transverse, broad and roughly quadrangular, with medial margins nearly straight; valvifers IX single, transverse, broad sclerite; laterotergites IX oblique, elongate; laterotergite VIII subtriangular with smooth caudal margin; spermatheca with proximal end of sclerotised rod, at the middle of lumen of spermathecal dilation, curved upwards; apical receptacle orbicular with three elongate ductules.

Differential diagnosis and remarks.

Breddin (1909) proposed Mycterizon to accommodate Dunnius bellus by understanding the fact that this species is unrelated from members of Dunnius and the need of a separate genus to accommodate the same. However, Distant (1918) synonymised Mycterizon with Dunnius without justifying his action. By studying the external morphology, male and female genitalia of the members of Dunnius , it was found that D. bellus is quite different from members of Dunnius in possession of the specific morphological characters, which are as follows: the shape of head (much broad, nearly 1.5 times as wide as long) and scutellum (broad, posteriorly U-shaped apex), short labium (reaching to mesocoxae), external scent efferent system (spout-shaped peritreme with distal end protruding, elevated from the pleural surface; peritreme extends to middle of metapleuron), presence of a narrow, median, longitudinal ridge on mesosternum (not extending anteriorly beyond procoxae), absence of a cruciform metasternal carina (without a notch or groove at the posterior end) apart from the male genitalia characters such as shape of genital capsule including dorsal rim (slightly concave medially, without denticle on infoldings of ventral rim) and ventral rim (broadly concave) and shape of paramere (broad crown possessing stout finger-like straight process). Therefore, the status of Mycterizon is reinstated from Dunnius Distant (1902) to accommodate Dunnius bellus (Distant, 1902) and thereby the status of Mycterizon bellus (Distant, 1902) Breddin 1909 is reinstated from Dunnius bellus (Distant, 1902).

Figures

Figures 63 - 68. Mycterizon bellus (Distant), stat. rev. 63 habitus (dorsal) 64 habitus (ventral) 65 external scent efferent system (arrow showing the peritreme) 66 close up of posterior end of ventral side of male abdomen 67 close up of posterior end of ventral side of female abdomen (terminalia) 68 genital capsule (dorsal). Scale bars: 1 mm (63, 64); 0.5 mm (65); 0.1 mm (66 - 68).