Megalofaciatus Taszakowski, Kim & Herczek, 2021

Taszakowski, Artur, Kim, Junggon, Damken, Claas, Wahab, Rodzay A., Herczek, Aleksander & Jung, Sunghoon, 2021, A remarkable new genus and two new species of the Gigantometopini (Hemiptera Heteroptera, Miridae, Isometopinae) from Brunei, Zootaxa 4970 (1), pp. 171-181 : 172-175

Genus: Megalofaciatus Taszakowski, Kim & Herczek gen. nov.

Type species: Megalofaciatus foliotibialis Taszakowski, Kim & Herczek sp. nov.

Diagnosis. Distinguished by the vertical, flattened head, impunctate but wrinkled, at least two times as high as wide, dorsally protruding over the level of the highest point of pronotum; vertex protruding above eye level, width clearly smaller than eye width; labium reaching first abdominal segment; calli strongly swollen and glossy, with few punctures; pronotum large, anterior and posterior lobes distinctly separated, posterior part strongly convex,

posterior part and pleurites of thorax with large, deep and dense punctures, posterior margin convex; scutellum strongly tumid; hemelytra hyaline, with sparse punctures, sparsely covered with brown setae; midfemur with four and hindfemur with five trichobothria; tarsi three-segmented.

Description. Male. Body elongate ( Fig. 1A ). Head: in frontal view: impunctate but wrinkled, height more than two times width, widest at the level of fovea antennalis, vertex protruding above eye level, frons strongly elongated dorso-ventrally, with a distinct longitudinal furrow at middle, extending from the point slightly below lower edge of eye to half its height, sides of the head concave at the base of the eyes, mandibular plate narrow, descending sharply to the base of the clypeus, maxillar plate not visible from the front, concave, fovea antennalis located significantly below the lower rim of the eyes on the posterior part of the maxillar plate, clypeus short, not protruding beyond the plane of the frons. lateral edges of the head with long, protruding setae ( Figs 1B, C ); in lateral view: short, strongly protruding over pronotal collar, exceeding over the highest point of pronotum; antennae cylindrical, segments I and II thick, segments III and IV thin; labium exceeding hindcoxae, second labial segment longest ( Fig. 1B ). Pronotal collar with a row of punctures; calli glossy, clearly swollen, separated by a shallow groove, with few small and weak punctures; posterior part of pronotum distinctly punctate, pronotal angle carinate, posterior margin convex; scutellum heart-shaped, with small punctures, strongly tumid, baso-medially depressed; thoracic pleura distinctly punctate ( Fig. 1B ); evaporatory area triangular, margins straight; ostiolar peritreme small, strongly convex; legs moderately thick and long; midfemur with four ( Fig. 2A ), hindfemur with five trichobothria ( Fig. 2B, C ); hindtibia strongly modified, leaf-shaped ( Fig. 2F ); tarsi three-segmented ( Fig. 2D ), claws without apical tooth ( Fig. 2E ). Abdomen covered with long setae. Genitalia: genital segment with scythe-shaped parameres; left paramere almost as long as right paramere, the sensory lobe of left paramere thicker than that of right one; sensory lobe of left paramere with several long setae, apical process elongate ( Fig. 3A ); right paramere with knee-shaped sensory lobe ( Fig. 3B ); endosoma sacciform and membranous ( Figs. 3C ).

Female: Unknown.

Remarks. Affiliation of Megalofaciatus to the Gigantometopini is clearly confirmed by the following features: compound eyes relatively small, significantly separated from each other, pronotum elongate and at least in part deeply punctate, calli separated by fossa, pronotal collar demarcated by a row of punctures and inflated scutellum ( Herczek 1993, Yasunaga et al. 2017). Until now, it was believed that Gigantometopini possess five or six trichobothria on both midfemur and hindfemur ( Yasunaga et al. 2017, Taszakowski et al. 2020). However, the described genus is characterised by the presence of four trichobothria on midfemur and five trichobothria on hindfemur. Therefore, it seems that the number of trichobothria on midfemur is more varied in this tribe, ranging from four to six.

The newly described genus is very characteristic and difficult to confuse with other genera of the tribe, from which it is clearly distinguished by the set of features mentioned in the diagnosis. Megalofaciatus is the second largest member of the tribe, with only the single known specimen of Gigantometopus rossi Schwartz & Schuh, 1990 being larger ( Schwartz & Schuh 1990). The most distinctive feature of genus is the shape of the head. Its height is more than two times width, and in the front view, it is clearly concave at the level of the lower edge of the eyes.

Strongly modified, leaf-shaped hindtibia of Megalofaciatus foliotibialis are a completely new and surprising feature at the tribal, subfamily, and even family level.

Etymology. Combined from Latinized from Greek adjective μεγάλε—“big” and Latin word facies—“face”; gender masculine.

Figures

FIGURE 1. Megalofaciatus foliotibialis: dorsal (A) and lateral view (B), head in frontal view (C).

FIGURE 2. Megalofaciatus foliotibialis: femur of the middle leg in ventrolateral view, showing trichobothrial pattern (A), the femur of the hind leg in ventral (B) and ventrolateral views (C), showing trichobothrial pattern, tarsus of the hind leg, dorsolateral view (D), pretarsus of the foreleg, lateral view (E), hind leg (F).

FIGURE 3. Male genitalia of Megalofaciatus foliotibialis: left paramere (A), right paramere (B), aedeagus in dorsal view (C).