Some Factors Affecting Mortality of Eggs and Newly Emerged Larvae of Ptinus tectus Boieldieu (Col: Ptinidae)

Abstract

When allowed to hatch in groups, egg mortality was caused by the first larvae to emerge. The presence of adult ptinus and of adult Sitophilus granarius also caused mortality. Addition of wheat grains reduced this mortality while adding flour conferred a high level of protection upon the eggs. The morality occurred on hatching or immediately there after. P. tectus and S. granarius are found together in warehouses but their habits are so different that competition appears unlikely. The high level of mortality resulting from this noncompetitive association is discussed in relation to published results on egg mortality in competitive situations.