These fast-moving, shield-shaped insects are named for their mottled brown coloration. They suck plant juices from the buds, fruit, and stems of many flowers, fruits, and vegetables, causing shoots to blacken and drop or become deformed. When they feed on fruits, they leave sunken, catfaced scars.
Adults overwinter in plant debris, so do a garden cleanup each fall. Plant under floating row covers. Sticky traps may attract the pests; soap sprays will kill those you hit directly. Spined soldier bugs are natural predators.
Chemical controls effective against adults include carbaryl and malathion.