Hand Warmer-Induced Hypoxia Accelerates Pest Control in Hermetic Storage

Accelerating oxygen depletion during hermetic storage can minimize pest damage and preserve product quality. This study evaluated the effectiveness of hand warmers in accelerating hypoxia to control insect pests inside hermetic containers. We used one, two, or four hand warmers to deplete oxygen in a 4-gallon hermetic jar with 4 kg of cowpea and cowpea bruchids, alongside a non-hermetic control with cowpea bruchids and no hand warmers. Oxygen levels, insect mortality, egg counts, seed moisture content, and germination rates were monitored over 2, 5, or 8 days of storage. Only the four hand warmers treatment reduced oxygen levels below 1% within 12 h and maintained them for up to 168 h. The other treatments did not achieve this level. Insect mortality was higher with more hand warmers and extended storage duration, reaching 100% after 5 and 8 days with four and two hand warmers, respectively. Similarly, increased hand warmers and extended storage durations reduced egg counts and adult emergence. The treatments did not affect the moisture content or germination rates of the stored cowpea seeds. Hand warmers proved effective in accelerating hypoxia during hermetic storage, resulting in high insect mortality and reduced reproduction, without compromising grain quality.