The following notes are based almost entirely upon actual rearing records, the hosts in most cases being insects of economic importance. The greatest attention has been paid to parasites of the small moth-borers of sugar-cane (Diatraea spp.). The systematic work has been done entirely at the British Museum and would have been impossible without the facilities in literature and collections there, and the great help of Mr. D. S. Wilkinson and Dr. C. Ferrière, of the Imperial Institute of Entomology. Types of new species are in the British Museum.