| Abstract: |
Pulse grains are a primary plant-protein source for a large share of the population, yet post-harvest storage losses inflicted by bruchid beetles remain a chronic constraint to food and seed security. The present study examined the infested stages of two dominant storage pests, Callosobruchus maculatus (Fabricius) and Callosobruchus chinensis (Linnaeus), across four commonly stored pulses, and quantified the comparative efficacy of botanical, inert-dust and conventional protectants against them. Stage-wise sampling over a ninety-day storage period revealed that the egg and concealed larval stages constituted the bulk of cryptic infestation, while emergence holes signalled the most damaging adult phase. C. maculatus showed a shorter developmental period and a higher intrinsic damage potential on cowpea, whereas C. chinensis was more aggressive on green gram and chickpea. Untreated controls recorded seed weight loss of up to 38.6 percent and germination decline to 41 percent, confirming the magnitude of unmanaged infestation. Among treatments, neem seed kernel powder and diatomaceous earth produced adult mortality above 85 percent, suppressed oviposition by more than 70 percent, and curtailed F1 adult emergence by over 80 percent, while preserving germination above 88 percent. Five data tables establish quantitative relationships linking infestation stage, species, host pulse and treatment outcome, directly supporting the conclusions drawn. |
