Aprostocetus Westwood 1833

Li, Xiangxiang, Xu, Zhihong, Zhu, Chaodong, Zhao, Jinnian & He, Yuyou, 2014, A new phytophagous eulophid wasp (Hymenoptera: Chalcidoidea: Eulophidae) that feeds within leaf buds and cones of Pinus massoniana, Zootaxa 3753 (4), pp. 391-397 : 392-393

Aprostocetus Westwood 1833

Aprostocetus Westwood, 1833: 444 . Type species: Aprostocetus caudatus Westwood

Asyntomosphyrum Girault, 1913: 71 . Type species: Asyntomosphyrum pax Girault. Synonymized by Bouček, 1988: 676.

Blattotetrastichus Girault, 1917: 257 . Type species: Entedon hagenowii Ratzeburg. Synonymized by Graham, 1961: 36.

Duotrastichus Girault, 1913: 257 . Type species: Duotrastichus monticola Girault. Synonymized by Bouček, 1988: 677.

Epentastichus Girault, 1913: 205 , 229. Type species: Epitetrastichus speciosissimus Girault. Synonymized by Bouček, 1988: 676.

Gyrolachnus Erdös, 1954: 365 . Type species: Gyrolachnus longulus Erdös. Synonymized by Graham, 1961: 44.

Hadrothrix Cameron, 1913: 175 . Type species: Hadrothrix purpurea Cameron. Synonymized by Graham, 1987: 129.

For more complete lists of synonymies see Graham (1961, 1987), Bouček (1988), LaSalle (1994) and Noyes (2012).

Description. Body metallic or non-metallic, with or without pale markings.

Head with malar sulcus present, usually straight or only slightly curved, occasionally foveate below eye. Eyes and ocelli fully developed. Mandible tridentate with outer tooth acute, middle and inner teeth progressively more obtuse. Female antenna with scape and pedicel having weakly engraved or obsolescent reticulation; anelli discoid to laminar, usually 4, rarely 3 or 2; funicle usually with 3, rarely 4, segments; clava most often with 3 segments but sometimes 2 owing to obsolescence of the second suture, very rarely solid. Male antenna with sculpture of scape and pedicel as in female; funicle with 4 segments, segments often with a whorl of elongate setae, clava with 3 segments.

Mesosoma with pronotum usually short or very short (rarely moderately long), without a transverse carina. Mid lobe of mesoscutum nearly always with 1 row of adnotaular setae on each side (rarely with 2 or 3 rows), the anterior setae usually shorter than posterior setae. Setae of pronotum and mesoscutum not all equal in length. Scutellum nearly always at least slightly broader than long; normally with 2 pairs of setae which are almost always nearer to submedian than to sublateral lines; submedian lines usually distinct (occasionally weak, rarely absent); sublateral lines neither broad nor deep. Propodeum with reticulation varying from obsolescent to slightly raised, never very strong; median carina present; plicae and paraspiracular carinae absent; spiracles in most species moderate-sized and suboval, very close to metanotum (occasionally very small and subcircular or very rarely large), the outer part of their rim nearly always partly covered by a raised flap of the callus. Legs with hind coxa lacking dorsolateral longitudinal carina; first segment of mid and hind tarsi at least as long as second (sometimes very slightly shorter) in most species. Wings nearly always macropterous (rarely shortened or almost rudimentary); costal cell with a row of setae on lower surface; submarginal vein usually with 2 or more dorsal setae (rarely only 1 seta); parastigma hardly ever marked off from marginal vein by a decolourized area; postmarginal vein absent to at most half as long as stigmal vein.

Gaster not strongly sclerotized, collapsing to a greater or lesser degree on air-drying; ovipositor sheaths usually projecting at least slightly (in rare cases even longer than the body), but occasionally not projecting; cercus most often with one seta slightly to very distinctly longer than the other and usually more or less sinuate or kinked near middle. Anterior margin of female hypopygium trilobed.

Remarks. Species of Aprostocetus can be separated from other genera of Tetrastichinae by the characters given in keys by Graham (1987, 1991) and LaSalle (1994). The description given above illustrates the great deal of morphological variation that is found within Aprostocetus , but as a general rule species can be recognized by having the following combination of characters: submarginal vein with 3 or more dorsal setae, one of the cercal setae distinctly longer than the remaining setae and sinuate, propodeal spiracle partially covered by a raised lobe or flap on the callus, malar sulcus straight or only slightly curved, and mesosternum usually flat just anterior to trochantinal lobes.

For notes on the Chinese species see Graham (1987), Sheng & Zhao (1995), Yang (1996), Wu et al. (2001), Zhu & Huang (2001, 2002), Yang et al. (2003), Xu & Huang (2004), Weng et al. (2007). At present there is no key to Chinese species of Aprostocetus .

Biological notes. With a very wide host range, but most often inhabiting plant galls made by insects, such as Diptera (Cecidomyiidae) or sometimes Hymenoptera (Cynipoidea) ,occasionally Coleoptera or Coccoidea, and rarely gall-inhabiting Acari ( Graham 1987). Only a single species of Aprostocetus has been definitely shown to be a gall inducer: A. colliguayae (Philippi) which induces galls on Colliguaja odorifera Molina (Euphorbiaceae) in Chile ( Martinez et al. 1992; La Salle 2005).

Distribution. Worldwide.