Ibalia Latreille, 1802

Noort, Simon van, Buffington, Matthew L. & Forshage, Mattias, 2015, Afrotropical Cynipoidea (Hymenoptera), ZooKeys 493, pp. 1-176 : 130-131

Taxon classification Animalia Hymenoptera Ibaliidae

Ibalia Latreille, 1802

Remarks.

In the Afrotropical region, the Ibaliidae are represented by an introduced Holarctic species. It was introduced to Australia, New Zealand and South Africa (1995-2007) to control Sirex noctilio Fabricius, 1793, a pest in pine plantations ( Pinus radiata D. Don.) ( van Noort and Picker 2011).

Diagnosis.

Readily distinguished from all other Afrotropical Cynipoidea by the sheer size of this wasp. Adults easily reach 1.5 cm; the closest, by size, to this group of wasps are some species of Oberthuerella , especially Oberthuerella lenticularis and Oberthuerella cyclopia . An additional character that readily seperates Ibalia from other cynipoids (and most other Hymenoptera , for that matter), is the extremely laterally flattened mesosoma. In dorsal view, the metasoma of Ibalia is blade-like, housing a long, coiled ovipositor. The large liopterids, mentioned above, all have a distinctly ovate metasoma, never laterally flattened. As in the case of the liopterids, ibaliids have a distinctly horizontally strigate mesoscutum, which is hypothesized to be critical in emerging from their wood-boring hosts ( Ronquist 1999).

Distribution.

Holarctic and transgressing into the northeast Oriental region, introduced elsewhere. Afrotropical records: South Africa ( Hurley et al. 2007).

Biology.

Parasitoids of woodwasps: Sirex , Urocerus and Xeris ( Siricidae ) living in conifers. Males mate with females while they are laying eggs. The female inserts her ovipositor down the tunnel bored in pine trees by the host woodwasp larva, to lay an egg either into the egg of the host or into the young host larva. On hatching the ibaliid wasp larva emerges from the body of the host and feeds externally ( Hurley et al. 2007).

Species richness.

Ibalia leucospoides (Hochenwarth, 1785) ( Ichneumon ) ssp. leucospoides Hochenwarth, 1785 (South Africa; extralimital distribution throughout the Holarctic region and introduced elsewhere)