Acalypta pallidicoronata, Souma, 2019

Souma, Jun, 2019, A new species and a new record of the genus Acalypta (Hemiptera: Heteroptera: Tingidae) from Japan, Zootaxa 4609 (1), pp. 178-184 : 180-183

Acalypta pallidicoronata , sp. nov.

( Figs. 1 C–D, 1G–H, 2B, 2D, 3B, 3D)

Type series. Holotype: brachypterous ♂, “ JAPAN Tsushima Is. Kamiagata-machi, near Mt. Kônoki-yama , 34.59020N 129.38092E, 6. IX. 2017, T. Ishikawa ” . Paratypes (15 ♂♂ 13 ♀♀, all brachypterous): as holotype (4 ♂♂); as holotype but 8.ix.2017 (1 ♀); as holotype but leg. J. Souma (3 ♂♂ 3 ♀♀); as holotype but 8.ix.2017, leg. J. Souma (8 ♂♂ 9 ♀♀).

Diagnosis. Recognized among other species of Acalypta by a combination of the following characters: body pale fuscous, elliptical in male and ovate in female, approximately 2 mm long from head to apices of hemelytra ( Figs. 1 C–D, 1G–H); antenniferous tubercles obtuse and slightly curved inward; pronotum unicarinate, 0.8 times as long as maximum width across paranota; calli with a faint median transverse furrow; paranotum with 2 rows of areolae throughout its length; anterolateral angle of paranotum rounded, not protruding anteriad, posterolateral angle not protruding posteriad; posterior process of pronotum short, 4 times as wide as its length; posterior margin of hemelytron straight, but slightly curved outward at apex; costal area with 2 rows of areolae in basal part and a single row in remaining parts; subcostal area with 7 rows of areolae at widest part; discoidal area considerably expanded beyond apical fourth of hemelytron, distinctly wider than subcostal area; discoidal-sutural boundary vein gradually obscured in its basal third; pygophore roundly inflated and semicircular, bulged evenly in venter, smooth on surface ( Figs. 2B , 3B); apical margin of female abdomen rounded ( Fig. 2D ); and paramere flat and short, angularly curved inward (Fig. 3D).

Description. Brachypterous male. General color pale fuscous; eyes red; antennae except segment III, calli, abdomen beneath and femora dark brown; body with golden pubescence ( Figs. 1C, G ).

Body ellipsoid, 1.8 times as long as maximum width across hemelytra ( Fig. 1C ). Head with several punctures on vertex; with a pair of very short frontal spines, their apices far remote from tip of tylus; antenniferous tubercles short and obtuse, slightly curved inward; juga deeply and coarsely punctate. Compound eyes prominent laterally, ellipsoidal in dorsal view. Antennae smooth, covered with pubescence; segments I thickest, not close to each other at their base, approximately 1.5 times as long as its width; segment II as long as its width; segment III tapering apicad, narrower than segment IV, slightly longer than head width across eyes; segment IV fusiform, widest a little beyond middle; relative lengths from segments I to IV as 1.6: 1.0: 6.0: 2.9. Bucculae widely open in front, approximately 1/3 as high as its length, with 3 rows of areolae at highest part. Rostrum almost same in length as antennae, slightly extending beyond posterior end of metasternal laminae.

Pronotum ( Fig. 1C ) unicarinate, 0.8 times as long as maximum width across paranota. Hood low and roofshaped ( Fig. 1G ); anterior margin roundly protruding forward, only concealing basal part of vertex. Median carina low but slightly concave at level of calli in lateral view, with a single row of minute areolae arranged throughout its length, but one of these areolae at level of calli conspicuously large. Calli weakly depressed, with faint median transverse furrow. Paranotum transversely expanding laterad, approximately 3.1 times as long as its width, with 2 rows of areolae throughout its length which are of subequal size ( Fig. 1C ); anterolateral angle rounded, not protruding anteriad; lateral margin gently curved outward; posterolateral angle rounded, not protruding posteriad. Posterior process short, 4 times as wide as its length.

Hemelytron narrow, 2.5 times as long as its width, strongly elevated in discoidal area, slightly extended beyond apex of abdomen ( Figs. 1C, G ); posterior margin straight, but slightly curved outward at apex; costal area narrow, slightly reflexed upward, with 2 rows of areolae in basal part and in a single row in remaining parts; subcostal area 3.3 times as wide as costal area at middle of hemelytron, with 6 rows of areolae at widest part; discoidal area very long and wide, considerably expanded beyond apical fourth of hemelytron, distinctly wider than subcostal area, with 6 rows of areolae at widest part; sutural area indistinctly delimited from discoidal area in basal part, with a single row of areolae in middle part and 2 rows in apical part; boundary veins strongly carinate, but discoidal-sutural

Remarks. In keys to the Japanese species of Acalypta ( Takeya 1962, Tomokuni 1972, Yamada & Tomokuni 2012) this new species does not run to any species due to having a combination of the following characters: body ellipsoidal or ovate; pronotum 0.8 times as long as maximum width across paranota; anterolateral angle of paranotum not protruding forward; and discoidal area distinctly wider than subcostal area ( Fig. 1 C–D).

Acalypta pallidicoronata sp. nov. closely matches the original description of A. sauteri (Drake 1942) . Although Tomokuni (1972) pointed out that A. sauteri exhibits considerable intraspecific variation, based on a direct comparison of the type material of the new species with hundreds of specimens of A. sauteri from different localities of Japan, the following characters are recognized to readily differentiate A. pallidicoronata sp. nov. from A. sauteri : general color pale fuscous; pronotum 0.8 times as long as maximum width across paranota; anterolateral angle of paranotum not protruding anteriad; posterolateral angle of paranotum not protruding posteriad; and discoidal area considerably expanded beyond apical fourth of hemelytron, distinctly wider than subcostal area ( Figs. 1 C–D). On the other hand, A. sauteri has the following features: general color dark fuscous; pronotum 0.6 times as long as maximum width across paranota; anterolateral angle of paranotum weakly protruding anteriad, not reaching midlevel of compound eye; posterolateral angle of paranotum protruding posteriad; and discoidal area not expanded beyond apical fourth of hemelytron, as wide as subcostal area at each widest part.

The new species resembles A. hirashimai and A. saundersi Downes, 1927 in the width of the costal area of hemelytron relative to the subcostal area, but is distinguished from them by the following characters: pronotum 0.8 times as long as maximum width across paranota; posterolateral angle of paranotum not protruding backward; posterior process short, 4 times as wide as its length; and costal area with 2 rows of areolae in basal part and a single row in remaining parts ( Figs. 1 C–D).

In general appearance, this new species slightly resembles A. duryi Drake, 1930 , A. miyamotoi and A. tsurugisana , but it is easily distinguished from them by the following characters: pronotum 0.8 times as long as maximum width across paranota; paranotum with 2 rows of areolae throughout its length; anterolateral angle of paranotum not protruding anteriad; discoidal area considerably expanded beyond apical fourth of hemelytron, distinctly wider than subcostal area; and costal area with 2 rows of areolae in basal part and a single row in remaining parts ( Figs. 1 C–D).

Members of Acalypta are divided into two species groups: those of which the pronotum is unicarinate and those of which it is tricarinate. All members of the former group are only known from brachypterous morphs ( Tomokuni 1983). Having an unicarinate pronotum, A. pallidicoronata sp. nov. belongs to the first group; similarly to other members of the group, no macropterous morph is know in this species either.

Distribution. Japan (Tsushima Island).

Etymology. The species epithet is the Latin adjective pallidus (meaning pale) and the Latin noun corona (meaning crown), referring to features of the pale and rounded paranotum.

Host-plant. Undetermined mosses.

Figures

FIGURE 1. A–H. Habitus of Acalypta species from Japan, dorsal and lateral view. A. cooleyi, brachypterous male (A, E) and macropterous female (B, F); A. pallidicoronata sp. nov., brachypterous male (C, G) and female (D, H). Scale bars: 1.0 mm.

FIGURE 2. A–D. Apical part of abdomen, ventral view. A. cooleyi, male (A) and female (C); A. pallidicoronata sp. nov., male (B) and female (D). Scale bars: 0.2 mm.