During the summers of 1927 and 1928, the rearing of the Braconid, Alysia manducator, Panz. (Bull. Ent. Res., xvii, pp. 219–229) for shipment to Australasia as a measure against the sheep-maggot, was continued on a large scale at the laboratory of the Imperial Bureau of Entomology, Farnham Royal, Bucks. In addition a study was made of the Anthomyiid, Hydrotaea dentipes, Fabr., as a possible natural enemy for the buffalo-fly, Lyperosia exigua, de Meij., which has become a serious pest of cattle and buffalos in Northern Australia. Owing to the cold and wet conditions prevailing in 1927, the results were very irregular; but certain general facts regarding the complex of necrophagous maggots, predacious maggots and their respective parasites, gathered during this work, seem worth recording.