Study of an infestation by Laemophloeus sp. (Coleoptera Cucujidae) in bulk wheat

Physical and biological data are presented from an infestation by Laemophloeus sp. (unidentified but very near to L. minutus Oliv.) in bulk wheat contained in open-topped silo bins. Much of the life history of this species is spent within the grains of wheat under the conditions of this infestation. It follows that the density of population of this species in whole wheat can be estimatedonly by breeding out or by determining the carbon dioxide output of the grain. Some larvae are free-living for part of their lives. No regular relation has been found between the number of larvae free-living at any time and the number of insects remaining within the grains. The proportion of the total population which is free-living is least when the total population is greatest. There is some evidence that the grain contained a light infestation of Laemophloeus , fairly evenly distributed, before it was loaded into the silo bin. It is supposed that this was the source of the infestation studied. Factors which might be responsible for the uneven development of the population are discussed.