A sustained release pheromone formulation is provided in which once it is secured to a branch or other support, the likelihood of falling off is significantly reduced, and which is capable of being quickly attached to a small or large branch. The sustained release pheromone formulation includes a first and second sheet parts which are provided by bending a single polymer sheet so that they are arranged in a face-to-face manner, the sheet parts each having an engaging hole therethrough; a bend part located between the sheet parts; at least one sex pheromone substance carried on at least a part of the sheet parts; and slits each extending from the bend part to the engaging hole in each one of the sheet parts. This formulation can be secured to the rod-shaped support by guiding the rod-shaped support to the engaging holes via the slits and engaging with the holes.
