Acanthia marginata: Wolff 1804: 132, new species, description and figures.

Acalypta marginata: Horváth 1906: 26, new combination, description; Putshkov 1974Horváth 1906: 169, monograph, description and figures; Golub 1982: 201, distribution and biology; Péricart 1983: 111, monograph, description and figures; Golub 1988: 140, key to species and figures; Péricart and Golub 1996: 8, catalogue; Rédei et al. 2004: 75, biology; Rintala and Rinne 2011: 74, monograph, description and figures; Aukema et al. 2013: 58, catalogue; Cho et al. 2020: 738, distribution and biology.

Acalypta marginata can be differentiated from other species of Acalypta by a combination of the following characteristics: both macropterous and brachypterous morphs known; body fuscous, elongate in brachypterous morph (Fig. 1a, b) and oblong in macropterous morph; antenniferous tubercles obtuse, slightly curved inwards; basal part of antennal segment III not thickened; rostrum reaching posterior margin of metasternum (Fig. 1c); pronotum tricarinate, 0.8 times as long as maximum width across paranota; hood concealing basal eighth of vertex; pronotal carinae laminate; calli coarsely punctate; paranotum with 2 rows of areolae at widest part; anterolateral angle of paranotum rounded, not protruding anteriad; posterolateral angle of paranotum not protruding posteriad; posterior process 2.2 times as wide as its length; posterior margin of hemelytron in brachypterous morph weakly sinuate; gap between both hemelytra in brachypterous morph distinctly narrower than discoidal area at widest part of each; costal area with a single row of areolae throughout its length; subcostal area with 3–5 rows of areolae at widest part; discoidal area with 3–5 rows at widest part, expanded beyond apical fourth of hemelytron in brachypterous morph, as wide as subcostal area at widest parts of each; and basal third of discoidal-sutural boundary vein carinate.

a

b

c

Figure 1.

Habitus images of Acalypta marginata from Hokkaido, Japan.

a: brachypterous male, dorsal view. Scale bar 1.0 mm.  
b: brachypterous male, lateral view. Scale bar 1.0 mm.  
c: rostrum, ventral view. Scale bar 0.2 mm.  

Japan (Hokkaido) (Fig. 2), Armenia(?), Austria, Azerbaijan, Belgium, Bosnia Herzegovina, Bulgaria, Byelorussia, Croatia, Czech Republic, Finland, France, Germany, Hungary, Italy, Latvia, Luxembourg, Moldavia, Mongolia, Netherlands, Norway, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine (Péricart and Golub 1996, Aukema et al. 2013, Cho et al. 2020).

Figure 2.  

Collection sites for Acalypta marginata from Hokkaido, Japan.

The host plant for Acalypta marginata in Japan is unknown. In other distribution areas, A. marginata is found on Rhytidiadelphus sp. (Hylocomiaceae); it is also found on herbaceous plants (Putshkov 1974, Péricart 1983, Rédei et al. 2004, Rintala and Rinne 2011).

Acalypta marginata is found in grasslands in Japan. In other distribution areas, A. marginata is known to be found in dry and sunny environments, such as grassy ground; however, it is sometimes collected from humid and shaded environments, such as the forest floor (cf. Putshkov 1974, Rédei et al. 2004).

In Japan, adults have been collected only in July and the overwintering stage is unknown. In other distribution areas, adults are found in almost all seasons and the overwintering stage is known to be the adult or elder nymph (Putshkov 1974, Péricart 1983, Rédei et al. 2004, Rintala and Rinne 2011).

The above-recorded specimens match well with the photographs of the non-types (Rintala and Rinne 2011), descriptions (Wolff 1804, Péricart and Golub 1996) and keys (Putshkov 1974, Golub 1988) of Acalypta marginata described from Hungary, based on the brachypterous morph.

Acalypta marginata is very similar to A. nigrina Fallén, 1807 in the shape of the antenniferous tubercles and the pronotum; however, the former is distinguished from the latter by the following characteristics: body fuscous and elongate in brachypterous morph (Fig. 1a, b). In contrast, A. nigrina has the following features: body dark grey and ovate in brachypterous morph.