Scolopostethus decoratus (Hahn, 1833)

(Figs. 12, 13, 31, 32, 49, 50, 71, 72, 87, 88, 101, 107, 114, 121, 128)

Pachymerus decoratus Hahn, 1833: 139.

Material examined. KYRGYZSTAN: Jalal-Abad, Ryzhikova leg., 31 V –9 VI 1909, 1♀; TAJIKISTAN: Novobad [Navobod] nr Stalinabad [Dushanbe], Kiritschenko leg., 19, 20 I, 2, 17 II 1944; 25 VII 1947, 8♀♀, 17♂♂; Stalinabad [Dushanbe], Kiritschenko leg., 16, 19, 29 I, 7 IV 1944, 1♀, 3♂♂; Gulbista Stream, Stalinabad [Dushanbe], Kiritschenko leg., 1 V 1943, 1♀; Gazni, right bank of the Varzob River, Kiritschenko leg., 14 II 1944, 17♀♀, 19♂♂; Penjikent [Panjakent], Zeravshan River valley, Kiritschenko leg., 27 XI, 12 XII 1943, 6♀♀, 4♂♂; floodplain of the Zeravshan River, Penjikent [Panjakent], Kiritschenko leg., 30 XI 1943, 1♀, 2♂♂; Khurmi, right bank of the Zeravshan River [nr Panjakent], Kiritschenko leg., 3 XII 1943, 1♀; Noudzhy [Nadzh], Gissar, valley, Kiritschenko leg., 23 II 1944, 10♀♀, 7♂♂; Parkhar [Farkhor] on the Panj River, Gussakovsky leg., 10 X 1935 1♀; Kabadiyan [Qubodiyon], Gussakovsky leg., 19 VI, 8, 10 VII 1934, 2♀♀, 1♂; TURKMENISTAN: AShgabat, Vlasov leg., 6 XII 1934, 6 II 1935, 1♀, 2♂; Geok Tapa [Geok Tepe], collection of V. Jakovlev, 1♀; UZBEKISTAN: Kitob, South of Bukhara, Gussakovsky leg., 29 V 1932, 1♀; Taschkent, collection of V. Jakovlev, 6♀♀, 5♂♂; Taschkent, Zarudny leg., 19–20 X 1907, 1♂; Termez nr Bukhara, Kiritshenko leg., 17 VI 1912, 1♀; Daul nr Samarkand, D-r. A.N. Kiritshenko leg., X 1911, 4ff.

Diagnosis. Body length 3.5–4.5 mm in female, 3.1–3.5 in male. All antennal segments dark brown to black, rarely with dirty yellow antennal segment I and sometimes base of segment II paler (Figs. 31, 32). Pronotum with darkened humeral angles and usually with two diffuse dark spots at sides of pale midline (Figs. 71, 72). Fore femur dark brown, dirty yellow apically and basally. Mesosternum without acute tubercule (Figs. 87, 88). Apex of corium widely darkened. Membrane whitish with dark brown apex and dark brown veins. Pronotum, scutellum, and hemelytron clothed with short, barely visible, tightly adpressed setae 0.25–0.33 times as long as width of hind tibia at middle with addition of rare erect short setae, giving impression of scarce vestiture (Fig. 101). Only macropterous specimens known (Figs. 12, 13). Lobe on inner margin of dorsal opening of pygophore as in Fig. 114A. Blade of paramere thin, not widened at middle, with rounded apex (Fig. 121).

Measurements given in Appendix 2 (Tables 1–4).

Scolopostethus decoratus is most similar to S. thomsoni in the short vestiture and coloration, but the latter species differs in having longer setae on hemelytron (Fig. 100) and the shape of the paramere with the blade strongly widened at middle and apically tapering in lateral view (Fig. 122). S. affinis, being similar to S. decoratus easily differs by the presence of acute tubercle on the mesosternum (Figs. 85–88), and the blade shape of the paramere (Fig. 120, lateral view).

Distribution. Almost entire Europe, Azores, North Africa, Israel, Caucasus, Iran, Central Asia (Péricart, 1998, 2001). The collection localities from Uzbekistan, Turkmenistan, Kyrgyzstan, and Tajikistan are shown in Fig. 134. In the work of Kiritshenko (1964), some of the records for S. decoratus refer to S. ferganensis sp. n. according to the localities and dates of collection. So, the records «Novobad [Navobod] nr Stalinabad [Dushanbe], Kiritschenko leg., 17 II 1944; Penjikent [Panjakent], valley of the Zeravshan River, Kiritshenko leg., 27 XI, 1943; Khurmi, right bank of the Zeravshan River [nr Panjakent], Kiritschenko leg., 3 XII 1943 » refer to both S. decoratus and S. ferganensis sp. n. The record « Khodzha-Obigarm, southern slope of the Gissar Range, Kiryanova leg., 26, V 1944 » refers only to S. ferganensis sp. n.

Natural History and Bionomics. See: Pfaler (1936), Woodward (1949), Thomas (1955), Eyles (1963, 1964), Putshkov (1969), Stehlík (1998) and others.

Scolopostethus decoratus is relatively xerophilic and inhabits mainly sandy biotopes with heather on wetlands in Western Europe. It is also found on the edges of birch forests (Finland, Ukraine) and even in damp places in Bulgaria (Josifov, 1964). This species feeds on seeds of Erica, Calluna, Betula, Carpinus, Capsella bursapastoris, Utrica dioica (Eyles, 1964; Putshkov, 1969). Stehlík (1998) also indicates the possibility of development of S. decoratus in the litter under cypress trees. S. decoratus mentioned as a facultative predator as well, it attacks Collembola (Woodward, 1949). Feeding on larvae of Orthotylus ericetorum (Miridae) has also been observed, but it is unclear whether this was an attack on living larvae or feeding on dead ones (Thomas, 1955). Eyles (1963) also mentions feeding on small invertebrates as a supplement to plant seeds diet.

The imago usually hibernates; larvae overwinter less often (Pfaler, 1936; Putshkov, 1969; Stehlík & Vavrinova, 1997; Péricart, 1998). Diapause does not occur in some regions of England, (Southwood & Leston, 1959). The oviposition begins in May. The egg development takes about 3 days. In Europe, larvae are found from June to early October. The larval development takes about 80 days (Eyles, 1963). Young adults appear from late July to late autumn. S. decoratus has one generation per year.