Synergus laeviventris (Osten-Sacken, 1861) Synophrus laeviventris Osten Sacken, 1861. Proc. Entomol. Soc. Phil. 1: 57. Type material: MCZ. Synergus laeviventris: Osten-Sacken (1865). Proc. Entomol. Soc. Phil. 4: 375. Diagnosis. See Lobato-Vila et al. (2020c: 19). Distribution. USA: Washington D.C. (Osten-Sacken 1861; Burks 1979), Colorado, and Michigan (Gillette 1896). Biology. Reared from galls of Amphibolips confluenta (Harris, 1841) on Q. rubra (Osten-Sacken 1861); from galls of Amphibolips quercusspongifica (Osten-Sacken, 1862), Atrusca quercuscentricola (Osten-Sacken, 1861), as well as from an unnamed gall on Q. falcata described by Osten-Sacken (1861) (Osten-Sacken 1865); and from galls of Disholcaspis rubens (Gillette, 1893) and D. quercusglobulus (Fitch, 1859) (Gillette 1896). Remarks. The type material of Synergus laeviventris was examined and the species was redescribed and illustrated by Lobato-Vila et al. (2020c: 19). The host plant is not mentioned neither for Amphibolips quercusspongifica, Atrusca quercuscentricola, Disholcaspis rubens nor D. quercusglobulus. However, and according to Burks (1979), A. quercusspongifica is associated with oaks of the Lobatae section (Q. coccinea, Q. marilandica, and Q. velutina); Atrusca quercuscentricola, with Q. stellata; Disholcaspis rubens, with some species of oaks from Quercus section (Q. arizonica, Q. x undulata, Q. gambelii, Q. oblongifolia, Q. rugosa, Q. turbinella, and Q. toumeyi); and D. quercusglobulus, with oaks from Quercus section (Q. alba, Q. prinoides, and ‘ Q. prinus ’).

Published as part of Lobato-Vila, Irene & Pujade-Villar, Juli, 2021, The genus Synergus Hartig (Hymenoptera: Cynipidae: Synergini) in the New World: a complete taxonomic revision with a key to species, pp. 1-121 in Zootaxa 4906 (1) on page 58, DOI: 10.11646/zootaxa.4906.1.1, http://zenodo.org/record/4434000