Placing a board on the ground, raised about one-inch, is another trap option. It provides a daytime hiding place for these pests that you can then lift to locate and dispose of them. Protect plants by sprinkling diatomaceous earth around the plants. Diatomaceous earth is very sharp and scratches the skin of these soft-bodied critters, resulting in dehydration and death. It must be reapplied after a rain or watering.
Various baits containing metaldehyde are also available.
Read and follow all label directions and precautions before use. This prevents the plant from making seeds and encourages more flowers to form. Cutting back the plants by one third will also stimulate new growth and extend the blooming period. They require strong filtered light, and flower best in full sun during cool weather. Pansy stems and flower stalks may be covered with small, wart-like bumps.