Siricid woodwasps and their associated parasitoids in the southwestern United States (Hymenoptera: Siricidae).
A survey of dead or dying conifers in Arizona, Colorado and New Mexico in 1971 revealed seven of the ten species of Siricids known to be present in those States, and also ten species of Hymenoptera that were known to be parasitic; details of emergence from Abies concolor, A. lasiocarpa, Picea engelmanni and Pinus ponderosa are given in graphs and a table. Sirex juvencus californicus (Ashm.) was associated with Pinus, and was probably parasitised by Rhyssa hoferi Rohw. and Ibalia ruficollis Cam.; S. longicauda Middlekauff, Urocerus californicus Nort. and Xeris morrisoni (Cress.) were associated only with Abies spp.; S. cyaneus F. emerged from both Abies and Picea; and X. spectrum (L.) emerged from all the tree species. The remaining parasite species could be traced to tree but not to host species.