Notes on some Natural Enemies of Plodia interpunctella and Silvanus surinamensis in Australia

Abstract

During the first half of 1927 the writer visited the chief grape-growing districts of Australia to investigate on behalf of the Empire Marketing Board and the Common-wealth Government the insect infestation of dried fruit. The more immediately practical results of this study were published in November 1928 (E.M.B., 12, 36 pp.). On pages 20–22 of that report the question of natural enemies was briefly considered. The present notes describe certain aspects of the behaviour of these natural enemies, with special reference, in the case of the “ parasites,” to oviposition habits. The literature on Microbracon hebetor, Say (Habrobracon juglandis, Ashm.) has grown enormously in the last few years, and the present section on this insect makes no pretence to deal with the mass of literature upon it, nor to summarise our knowledge of its biology. Among more monographic papers on M. hebetor may be mentioned those of Hase (the subject at first determined in error as Habrobracon brevicornis) and Genieys (chiefly morphological). Showell (Jl. Dept. Agric. South Australia, xxxi, 1928, pp. 1048–1056), has recently published an account of the life-history under Australian conditions ; while Schultze (1924) has described its psychology, with special reference to cleaning-habits and antennal movements. Schultze's work I have not seen.