Technical Details of Pheromone and Lure Production
A standard lure contains the following ingredients:
Pheromone
4. Butylated hydroxy toluene (BHT) 542 µ g
The isomeric purity of the pheromone components has been shown not to be critical down to at least 90%.
Lure Manufacture
The best dispenser is a capped polythene vial (32 % 15 % 2 mm thick) into which the pheromone is impregnated in a small suitable amount of nonpolar, rapidly evaporating solvent. Hexane or 60/80 petroleum spirit are ideal, while ethanol and methanol are not. The release rate characteristics of the particular polythene used are important (see list of suppliers).
To make 1000 lures, mix 500 mg of component (1), 25 mg of component (2), and 16.5 mg of component (3) in 99 mL of solvent. To this is added 542 mg of antioxidant and the components are thoroughly mixed. A reliable dispensing pipette (RePette or Eppendorf are ideal, see suppliers' list) is then used to inject 0.1 mL of the resulting mixture into each lure. Where large numbers of lures are being made, they should be prepared in a fume cupboard or an extremely well ventilated room. The solvent is left to evaporate (only a few minutes at ambient tropical temperatures) before the vials are capped. Ideally, lures are then sealed in aluminum foil and marked with the name of the species, date of manufacture, and batch number. If this is not possible, they should be stored in airtight glass or metal (not plastic) containers. In this form, they can be stored in a domestic refrigerator for a season (indefinitely in the freezer compartment). However, under ambient tropical temperatures, lures should be used within 3 months of manufacture if not kept refrigerated. When the foil seal is broken, lures should be placed in traps within 24 hours, as the pheromone will start to be released immediately.