Synergus Hartig, 1840

Nieves-Aldrey, Jose Luis & Medianero, Enrique, 2011, Taxonomy of inquilines of oak gall wasps of Panama, with description of eight new species of Synergus Hartig (Hymenoptera, Cynipidae, Synergini), Zootaxa 2774, pp. 1-47 : 4

Synergus Hartig, 1840

Diagnosis. Female antenna 14 segmented, male antenna with 15 or, rarely, 16 segments. Facial striae irradiating from the clypeus reaching the toruli and the compound eyes. Frontal carinae usually present, sometimes weak or even completely absent. Lateral pronotal carine present in most Palaearctic species, usually absent in Neotropical species. Sculpture of the mesoscutum, shape of the notauli and the scutellar foveae quite variable; lateral propodeal carinae subparallel. Radial cell of the forewing usually closed, sometimes obsoletely closed, rarely open. Metatarsal claws with a strong basal tooth, rarely simple. Metasomal terguites 2+3 usually with micropunctures on the posterior margin: sometimes inconspicuous or completely absent.

Synergus is closely related to Saphonecrus and S ynophrus, and doubts remain about the relationship between these three genera. Some basal Synergus species appear to be closely related to Saphonecrus ( Acs et al. 2010) .

Mayr (1872) divided the European Synergus species into sections I and II, a classification that has been followed by most subsequent authors ( Tavares 1920; Eady & Quinlan 1963; Nieves-Aldrey 2001; Pujade-Villar et al. 2003; Melika 2006). However, recent molecular phylogenetic studies strongly indicated that this division was artificial and should not be followed.

Diversity and Distribution. The world fauna of Synergus species were catalogued by Ritchie (1984), who listed 104 species throughout the Holarctic region. Gillette (1896) revised the 24 Nearctic Synergus species known at that time, and an additional 29 species have been described since ( Burks 1979). Ritchie & Shorthouse (1987) revised the species from Guatemala, and new species were described from Nicaragua ( Diaz & Gallardo 1998) and Colombia ( Nieves-Aldrey 2005) The current estimate of the world fauna includes approximately 100 valid species.

Biology. Synergus species attack galls on Quercus spp., with the exceptions of S. castanopsidis (Beutenmueller) , which is known to attack galls of Dryocosmus castanopsidis on Castanopsis spp. in Oregon and California ( Burks 1979; Pujade-Villar & Melika 2005), and an unnamed Synergus species from Japan that has been reared from galls of Dryocosmus kuriphilus Yasumatsu on the chestnut Castanea ( Otake et al. 1982) .

First recorded from Panama.