Starch extrusion technology was used to produce carriers for ‘contact baits’ that utilise aspects of feeding (or other) behaviour for the purpose of attraction and stimulation of grasshoppers and locusts and achieve uptake of the active ingredient by contact rather than ingestion. A rapid, continuous and efficient production of bait carrier was achieved using a co-rotating, twin-screw food extruder. Extrusion conditions were adjusted to produce a rigid, hard and highly expanded maize-starch extrudate, and laboratory bioassay demonstrated a high degree of acceptance of maize-starch baits by Schistocerca gregaria. Bait formulations that achieve dose transfer by contact rather than ingestion may be particularly appropriate for the formulation of fungal entomopathogens that infect by contact rather than ingestion.
Caudwell, R.W.; Gatehouse, A.G. Formulation of grasshopper and locust entomopathogens in baits using starch extrusion technology. Crop Protection (1996) 15 (1) 33-37. [DOI: 10.1016/0261-2194(95)00098-4]