Separating the grains from the chaff, and all the pests that move with it

Contributed by Melanie Bateman, CABI Switzerland, and Roger Day, CABI Africa

Larger stem borer, threat to food security (image: infonet-biovision)

While responding to a food crisis in Tanzania in the 1970s, evidence indicates that the larger grain borer (Prostephanus truncatus) was inadvertently introduced into Africa through an infested food aid shipment[1]. Following this introduction and a later introduction in West Africa, the larger grain borer has now spread to almost 20 different countries in Africa, causing significant losses to grains in the field and in storage both for food and for planting. Consequently, this fateful incursion has had a significant impact on food security in the continent. Even now, other alien pest species such as beetles, snails, weeds and pathogens[2] are intercepted in shipments of grains worldwide. Should these pests become established in new areas, farmers will be confronted with problems they may be ill equipped to solve.

 In order to address this pathway for pest spread, the Commission on Phytosanitary Measures added the topic of the international movement of grains to its work programme and member countries were asked to agree on the best way to approach the issue. While several countries noted the broad scope and complexity of the topic, many countries urged for the development of an international standard. Jack-Vesper Suglo of Ghana noted that

“the movement of grain is important for food, but it is also a major means of movement of pests. Africa has been the victim of the movement of pests through grain.”

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