Diadegma stellenboschense (Cameron) is a widely distributed parasitoid in South Africa. It attacks potato tuber moth larvae of all ages in foliage and tubers. It was successfully mass-reared under laboratory conditions and its biology studied. The five larval instars are followed by a prepupal stage; development from egg to adult occupied 18 days at 25ï¿½C. Successful development from egg to adult in ligatured hosts indicated that the host hormone system plays no part in normal development of this parasitoid. Observations on oviposition and longevity are reported. Indigenous natural hosts of this parasitoid are unknown at this stage but must clearly occur in abundance.
Recent work by the writer on the predacious Coccinellidae associated with the wheat aphid, Schizaphis graminum (Rond.), has provided an opportunity for reviewing the scope of this pest problem in South Africa and for furnishing background information. The purpose of this short communication is to summarize all available information so as to bring the problem into sharper focus.
Met die oog op die skepping van nuwe oorsese markte vir Suid-Afrikaanse sitrusvrugte is dit noodsaaklik dat 'n geskikte phytosanitï¿½re metode ontwikkel word wat vrugte sal vrywaar van lewendige valskodlingmot larwes. Sulke studies vereis groot getalle eksperimentele materiaal wat alleen verkry kan word deur 'n kunsmatige teï¿½Iprogram.