Oxygen demand of bean bruchids (Acanthoscelides obtectus Say)

Abstract

The common bean (Phaseolus vulgaris L) is an important crop in many countries and its safe storage is crucial in maintaining a sufficient and high quality food supply for the community. A non-chemical storage technique, hermetic storage, is being used to control the bean bruchid (Acanthoscelides obtectus Say), a beetle which can cause large losses to stored beans. Experiments were carried out using hermetically sealed containers of known gas volume at different temperatures (10 and 27°C) and bean moistures (8 and 16% wet basis) to quantify the oxygen requirement of bruchids. Bruchids use between 0.0074 and 0.1043 cm3 bruchid-1day-1, depending on bean temperature and bean moisture content. Days to 100% adult bruchid mortality in hermetic storage, as a function of infestation level, storage volume, temperature and bean moisture content, can be estimated by using these oxygen requirement results. These estimates can be used to design hermetic storage systems to protect beans from damage by bruchids. Key words: Beans, bean bruchids, hermetic storage, insects, oxygen demand, storage losses.