Infestations by Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) are very difficult to detect by visual inspection. Once signs of infestation are visible much damage has already been done. Pheromone baited traps (natural attractants produced by one insect to attract another of the same species) can detect low-level infestations. These traps are used to expose populations in stores as well as in the field before harvest and in non-crop natural habitats in which the beetle would otherwise be almost impossible to detect.
AgriSense-BCS manufactures two types of trapping system, in collaboration with the Natural Resources Institute (NRI), to monitor P. truncatus. The 'Delta Trap' is used to;
· Confirm presence of pest in both store and field.
· Highlight extent of infestation.
· Target use of insecticides.
· Indicate efficacy of control measures.
The Delta Trap is designed for monitoring external perimeters of stores, in markets or transhipment areas. Catches in these outdoor traps confirm the presence of LGB and allow preventative measures to be taken before the pest infests the crop within.
· Delta Traps are supplied flat and have to be assembled before use. This is a simple procedure and instructions are provided with the product.· Label the trap with its position and date of placement.
· Suspend the trap from a suitable support e.g. a tree or maize plant. The traps should he between one and three metres above ground level.
· Delta Traps should be used at the rate of one per hectare area. Traps placed closer than 100 metres apart are likely to interfere with one another.
If present, Prostephanus truncatus should be caught in a Delta Trap within 2-3 days.
