1. Agrios GN (1988) Plant pathology. (3rd edn). Academic, New York
2. Askew RR (1961) On the biology of the inhabitants of oak galls of the Cynipidae in Britain. Trans Br Soc Entomol 14:237?268
3. Bronner R (1977) Contribution � l'�tude histoquimique des tissus nourriciers des zooc�cidies. Marcellia 40:1?34
4. Bugbee RE (1957) Four new species of the genus Eurytoma from galls on hackberry (Chalcidoidea, Hymenoptera). J Kans Entomol Soc 30:45?50
5. Carroll G (1986) The biology of endophytism in plants with particular reference to woody perennials. In: Fokkema NJ, van den Heuvel J (eds) Microbiology of the phylloplane, Cambridge, University Press, Cambridge, England, pp 205?222