Abstract
Laemophloeus minutus (Ol.) has been reared on six food materials of a type with which the genus, Laemophloeus, is commonly associated in the field. Consideration of the length of egg to adult development, together with the mortality, recorded from each medium indicates that Manitoba wheat and whole-meal flour are equally favourable for the development of the species, followed in order of precedence by Plate maize, English wheat and, finally, National (85 per cent. extraction) and Canadian (70–75 per cent. extraction) flour which proved equally unfavourable.The stage of the life-history at which mortality mainly occurred varied with the diet. The high death-rate on English wheat was caused by the inability of newly hatched larvae to enter grains undamaged in the germ region. Mortality on National and Canadian flour occurred chiefly in the fourth instar.There were indications of cannibalism in both larval and adult stages, at any rate when the diet was unfavourable.The germ of wheat was attacked in preference to any other part of the grain. Maize germ was also consumed but whether it was preferred to the same extent as that of wheat was not established.Pupation was mainly, but not exclusively, intergranular in wheat. Normal cocoons were formed in National and Canadian flours but some larvae pupated in loose webbing or in flour free from webbing and freshly emerged adults were observed in unwebbed National and Canadian flour.