Phytosanitary Measures Against Larger Grain Borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), in International Trade

The establishment of P. truncatus in Africa has highlighted the inherent weakness of phytosanitary measures against exotic pests. Consideration is given to the need for phytosanitary measures and how patterns of international trade affect phytosanitary control. To prevent the spread of pests such as P. truncatus, large grain shipments can be subject to stringent pest control procedures. However, a significant proportion of grain movement in Africa, both within countries and across borders, occurs informally by both illicit, commercial movement of multiple truckloads of grain and legally by individuals carrying headloads via bush paths or small parcels on public transport. Attempts to locate and inspect the small lots would be impractical. Some recommendations are given on how the spread of P. truncatus in large-scale international trade can be slowed but otherwise it is accepted that in the long-term the prevention of further spread of P. truncatus in Africa is wholly unrealistic.