Hi,
here you can download a very interisting paper recently published by M. Pärn, V. Soon, T. Vallisoo, K. Hovi & J. Luig (2015) on the hosts of chrysidids.
The tile is: Host specificity of the tribe Chrysidini (Hymenoptera: Chrysididae) in Estonia ascertained with trap-nesting. European Journal of Entomology 112 (1): 91-99.
Cheers
Paolo