Provided herein are high-load, solid and liquid pesticidal compositions containing a low-melting active ingredient, which exhibit good physical and chemical stability, and equivalent or improved biological efficacy compared to liquid compositions when used to control pests in crop or non-crop environments. The temperature of the powder mixture is raised to firing temperature at 100\xb0 C. If the amount of level variation exceeds a predetermined value, the other antenna is used by changing over the switch 44.