Anastatus (Anastatus) bifasciatus (Geoffroy)

Figs 1, 2

Cynips bifasciatus Geoffroy in Fourcroy 1785: 388 . Described: female.

Diplolepis bifasciata (Geoffroy); Dalla Torre, 1898: 418.

Anastatus bifasciatus (Geoffroy); Nikol’skaya, 1952: 490, fig. 477.

Anastatus (Anastatus) bifasciatus (Geoffroy); Gibson, 1995: 105 (by implication); Narendran, 2009: 78, fig. 12.

Cinips bifasciata Fonscolombe, 1832: 294 . Described: female. Synonymy by Bouček, 1970: 80.

Pteromalus bifasciatus (Fonscolombe); Nees ab Esenbeck, 1834: 426.

Eupelmus bifasciatus (Fonscolombe); Förster, 1860: 122.

Anastatus bifasciatus (Fonscolombe); Ruschka, 1921: 264

Anastatus eurycephalus Masi, 1919: 321–324, figs 26(1–5), 27. Described: female. Synonym of A. bifasciatus (Fonscolombe) by Bolívar y Pieltain, 1935: 280; synonymy by Bouček, 1970: 80.

Cerycium pretense Erdős, 1946: 138–139, figs 4a–b. Described: male. Synonymy by Bouček, 1970: 80.

Cinips bombycum Fonscolombe, 1832: 295 . Described: male. Synonymy by Graham, 1992: 1101.

Diplolepis bombycum; Dalla Torre, 1898: 418.

Eupelmus subaeneus De Stefani, 1898: 251 . Described: female. Synonymy by Bouček, 1970: 80.

Pteromalus oomyzus Rondani, 1872: 202–203 . Described: male (see Bouček 1974: 261). Synonymy by Bouček, 1974: 261, 277.

Misocoris oomyzus; Rondani, 1877: 187, plate II, figs 55–58.

Misocoris oophagus Rondani, 1877: 187, plate II, figs 61–63. Described: male. Synonymy by Bouček, 1974: 262, 277.

Pteromalus ovivorus Rondani, 1872: 203 . Described: female. Synonymy by Bouček, 1974: 262, 277.

Misocoris ovivorus; Rondani, 1877: 187, plate II, figs 59–60.

Cynips gemmarum Fonscolombe, 1832: 296 . Described: male. Synonymy by Bouček, 1970: 80.

Pteromalus gemmarum; Nees ab Esenbeck, 1834: 425.

Diagnosis. FEMALE. Macropterous (Figs 1A, B). Fore wing with hyaline cross band behind marginal vein complete and with entirely white setae (Fig. 1D); infuscate region basal of hyaline band with uniformly dark setae and about 2.5–3.0× wider than cross band (Fig. 1D); basal region with basal cell, mediocubital fold, and cubital and vanal areas bare (Fig. 1F: bac, mcf, cua, vna). Head (Fig. 1E) with scrobal depression distinctly separated from anterior ocellus, by distance at least equal to 2× longitudinal diameter of ocellus (Fig. 1E: osd). Antenna (Fig. 1C) with fl2 slightly longer than pedicel (Fig. 1C, insert), but not all funiculars longer than wide, with at least apical two funiculars quadrate to slightly transverse (Fig. 1C). Mesosoma (Figs 1A, B), including procoxa (Fig. 1B), entirely dark, with concave posteromedial part of mesoscutum similarly dark as rest of mesoscutum (Fig. 1G) though under some angles of light with slight metallic luster; mesotibial apical spur infuscate (Fig. 1I); mesotarsus usually (see further under Remarks) similarly infuscate as mesotibial apical spur and similar in colour to mesotarsal pegs (Fig. 1B). Mesoscutum (Fig. 1G) with convex anterior part of medial lobe extensively mesh-like coriaceous at least anteriorly, at most distinctly reticulate only posteriorly, and with concave posterior part of mesoscutum only very sparsely setose with dark hair-like setae; mesoscutal lateral lobe with bare, minutely mesh-like coriaceous band anterior of posteromedian carina relative to distinctly larger mesh-like coriaceous to coriaceous-imbricate or reticulate sculpture on outer inclined surface (Fig. 1G). Profemur with ventral margin evenly curved, without distinct angulation or tooth apically (Fig. 1H).

MALE. Antenna with scape (Fig. 2E) extensively dark dorsally but yellow ventrolongitudinally; pedicel dark; flagellum (Figs 2B, E) uniformly dark such that multiporous plate sensilla not contrasting in colour with surrounding cuticle, and consisting of five funiculars and clava, with clava (Fig.2E: clv) more than twice as long as combined length of funiculars. Head with frons mostly to entirely mesh-like coriaceous (Fig. 2C), at most slightly roughened in part. Mesopleurosternum uniformly dark (Fig. 2D) or at most with transepisternal line variably distinctly paler. Legs (Fig. 2B) beyond trochanters with all femora and tibiae extensively dark but front leg with knee, inner surface and apex of tibia, and all but apical tarsomere pale; middle leg with knee, tibia apically, and all but apical tarsomere pale, and hind leg with knee and basal three or four tarsomeres pale. Fore wing (Fig. 2F) with costal cell dorsally setose along entire leading margin (Fig. 2G); basal cell at least uniformly setose along basal and mediocubital folds though variably setose within cell and setae often white and inconspicuous; disc with large, quadrangular speculum (Fig. 2F: spc), the ventral surface with only 1 or 2 lines of setae adjacent to parastigma, and comparatively inconspicuously closed posteriorly by line of white setae.

Species concept. Our concept of A. bifasciatus is based on identified specimens from Croatia, Cyprus, France, Greece, Hungary, Iran, Italy and Switzerland in the CNC, including reared material from Stahl et al. (2018a).

Regional records. Reported from mainland China by Chu et al. (1935) and from Taiwan by Yie and Hsu (1967) under the name A. gastropachae, which Noyes (2019) listed, incorrectly, as a junior synonym of A. bifasciatus following Ishii (1938) (see under A. gastropachae). We did not examine voucher material from Chu et al. (1935) or Yie and Hsu (1967), but assuming their identifications of A. gastropachae were correct, then evidence for the presence of A. bifasciatus in China is completely lacking. However, because of past confusion between A. bifasciatus and A. gastropachae as well as between A. bifasciatus and A. japonicus (see below) we treat the name so that all three species can be distinguished reliably if A. bifasciatus is eventually found in China. It is possible that the species occurs at least in the Palaearctic part of China if the records from Japan and South Korea are accurate (see below).

Distribution. Noyes (2019) recorded A. bifasciatus from throughout the Palaearctic region, including Europe and the Middle East, northern Africa, and Japan and Korea in the eastern Palaearctic, as well as Kenya (Afrotropical), India (Oriental), and United States of America (Nearctic). However, as discussed by Hayat (1975: 268), the record of Narayanan et al. (1967) is a misidentification of A. japonicus and subsequent inclusions of A. bifasciatus in the Indian fauna, such as by Narendran (2009), are based on prior literature records rather than validating specimens. Likewise, Nearctic records, such as by Crossman (1925), are based on misidentifications of A. japonicus and it remains to be confirmed whether A. bifasciatus occurs outside the Palaearctic region.

Hosts. Noyes (2019) listed A. bifasciatus as a parasitoid of about 30 species of Hemiptera, Lepidoptera, and Orthoptera plus, as a hyperparasitoid, two species of Braconidae (Hymenoptera) . However, some of the listed host records are undoubtedly based on misidentification of the parasitoid.

This species is currently being investigated for potential augmentative biocontrol of an invasive agricultural pest, Halyomorpha halys (Stål, 1855) ( Hemiptera: Pentatomidae), in Europe (Haye et al. 2014; Stahl et al. 2018a, 2018b). Its extensive putative host range, including Dendrolimus punctatus (Walker, 1855) ( Lepidoptera: Lasiocampidae) and other lepidopteran and hemipteran pest species, suggests potential for biocontrol in China as well.

Remarks. Females of A. bifasciatus are similar to those of A. colemani in sharing a complete fore wing hyaline cross band (Figs 1D, 3F) in combination with similar mesoscutal sculpture and setal patterns (Figs 1G, 3E). However, females of A. colemani have a short but distinct spine-like projection ventrally on the profemur within about its apical third (Fig. 3I: arrow), setae within the fore wing basal region (Fig. 3H), and the concave posteromedial part of the mesoscutum contrasting quite conspicuously in colour to the rest of the mesoscutum because of distinctly brighter metallic luster (Fig. 3E). Females of A. bifasciatus do not have a profemoral tooth (Fig. 1H), have the basal region of the fore wing entirely bare (Fig. 1F), and have the mesoscutum more-or-less uniformly dark with at most slight metallic luster (Fig. 1G). Three females from Iran that we provisionally identify as A. bifasciatus have entirely pale mesotarsi. However, all other examined A. bifasciatus females have infuscate mesotarsi that are similar in colour to the mesotarsal pegs and mesotibia (Fig. 1I). The few A. colemani females examined have at least the basal four mesotarsomeres pale in distinct contrast to the pegs and tibia (Fig. 3J). Females of both species have an infuscate mesotibial apical spur (Figs 1I, 3J).

Unfortunately, males of A. colemani are unknown, but males of A. bifasciatus are distinguished from males of all other treated species by flagellar structure. The clava (Fig. 2E: clv) is greatly elongate compared to other species and there are only five funiculars, which suggests that length of the clava is at least partly a consequence of fusion of the apical two funiculars with the clava. This difference in flagellar structure demonstrates that the redescription of the male of A. bifasciatus by Tachikawa (1959) actually was a misidentification of A. japonicus (see further under this latter species).