A comprehensive survey of the Tabora region of Tanzania was undertaken to observe the distribution of Prostephanus truncatus (the greater grain borer), a pest of stored maize. The pest was found in grain stores in 46 villages from a total of 56 examined, in all four districts of the region, being absent only in eastern lgunga, a sorghum-growing area, and in the southern part of the Taoora district. The pest was found in the Shinyanga region and in markets in the Mwanza region and at stores at Kilosa in the Morogoro region. After 4-6 months storage, maize samples collected from the villages in the Tabora region exhibited as much as 34% weight loss. Damage on this scale in a period of very dry weather, in very dry maize (average 11.2% moisture content) is extraordinarily high and demonstrates the destructive nature of this pest. Without doubt the pest will cause both a serious and widespread grain shortage in the region later and a dearth of seed grain for the coming growing season. Besides attacking maize, the pest also heavily damaged cassava and, to a lesser extent, other commodities such as groundnuts. Wooden implements and storage structures were also damaged. From the survey it is concluded that P. truncatus has become very well established in West Central Tanzania and is of major importance as a pest of stored produce. The outbreak must be seen to be of grave significance to the region. Unless effective measures to control and contain it are rigidly enforced the pest will spread throughout the rest of the country. The beetle poses a very real threat throughout East and Central Africa. Insecticide trials were established to assess the effectiveness of different treatments for the control of this pest in farm storage. These trials will continue. This account of the investigation was prepared whilst the team was in Tanzania. It was presented together with specific recommendations for the control and containment of the infestation at a final meeting between the team and the Ministry of Agriculture. The Tanzanian authorities have already taken steps to inform the international community through the FAO. They also agreed that the scientific results of the investigation could be made generally available
