Please also refer to the following link for details on this group:
Ibaliidae = Link 1
Ibaliidae. -- The ibaliids are large 7-18 mm long and have the abdomen elongated. They are parasitoids of horntails (Siricidae & Anaxyelidae). Included are some of the largest of the Cynipoidea (15 mm.+ long)., and with the most complex wing venations. They are a rare group that is not often observed or collected. Adults are black or brown in color, with an elongates and compressed abdomen. The gaster is almost sessile. The forewing has brown spots medially and apically. The abdomen is laterally flattened, and the ovipositor is stored in a sheath. With their antennae the adults locate the tunnels made by woodwasps, and eggs are deposited in the host's body cavity..
The distribution is Holarctic, but they have been introduced to New Zealand, Southern Africa and Australia.
Burks, B. D., K. V. Krombein, P. D. Hurd, D. R. Smith & B. D. Burks (eds.) 1979. Superfamily Cynipoidea. Catalog Hymenoptera in America North of Mexico 1: 1045-1107. Smithsonian Inst. Press, Washington, D.C.
Chrystal, R. N. 1930. Oxford Forestry Mem. 11: 1-63.
Kerrich, G. J. 1973. On the taxonomy of some forms of Ibalia Latreille (Hymenoptera: Cynipoidea) associated with conifers. Zool. J. Linn. Soc. 53: 65-79.
Liu, Zhiwei & G. Nordlander. 1994. Review of the family Iballidae (Hymenoptera: Cynipoidea) with keys to genera and species of the world. Entomologica Scandinavica 25(4): 377-92.
Nordlander, G., Z. Liu & F. Ronquist. 1996. Phylogeny and historical bigeography of the cynipoid wasp family Ibaliidae (Hymenoptera). Systematic Entomology 21(2): 151-66.
Ronquist, Fredrik. 1999. Phylogeny and classification and evolution of the Cynipoidea. Zoologica Scripta 28(1-2): 139-64.
Weld, L. H. 1951. Cynipoidea. Private Printing, Ann Arbor, Mich. 351 p.