The relationship between Plodia interpunctella (Hb.) (Lepidoptera, Phycitidae) and stored-grain fungi

The development of Plodia interpunctella, in shelled corn (maize) discouraged the growth of stored grain fungi, and slightly raised the moisture content of the infested corn. Mouldy corn, on the other hand, hindered the development of this insect. Fewer larvae reached the adult stage on mouldy corn and only after a prolonged developmental period; the adults produced were smaller in size and produced fewer eggs in their ovaries than those on mould-free corn. The more mouldy the corn the more it became unfavourable for the insect but this depended in part on the fungus species present. The relationship between this insect and the majority of stored grain fungi appeared to be antagonistic. An exceptional relationship was found with Aspergillus halophilicus, in plated cultures, which attracted the adult insect to lay its eggs and on this fungus larvae developed almost as normally as on mould-free corn.