A formulation for the control of arthropod pests comprising one or more hydrophobic or non-polar semiochemicals, water, a thickener and a rubber crumb carrier. The formulation may also include additives such as a feeding stimulant or bait, toxicant or insecticide, anti-microbial agent, humectant, volatility suppressant, pigment and an anti-oxidant. The invention also includes a method of preparing a formulation for controlling arthropod pests, said method comprising the steps of (i) admixing a carrier which includes rubber crumb with one or a plurality of hydrophobic or non-polar semiochemicals for a period of time sufficient for the rubber crumb to absorb the semiochemical, wherein the semiochemical is substantially dispersed throughout the rubber crumb; and (ii) combining the rubber crumb mixture of step (i) with water or an aqueous medium comprising a thickener.