This looks like the clavate tortoise beetle adult. The adults and larvae feed more commonly on potato leaves, but they can occasionally feed on tomato, bean and pepper leaves. There are some records of this beetle feeding on spinach, but spinach is not a preferred host. They are most commonly encountered on the ornamental sweet potato plants that are being grown in hanging baskets. These are a type of leaf beetle that have spiny larvae that feed on the foliage of host plants.  The adults of this species can be spectacular when they are in the full sun as they can turn a bright gold color, but when disturbed, they revert back to the brown pattern.  If controls are needed, insecticidal soaps will kill the adults and larvae if the spray contacts the insect. Insecticides containing the botanical azadirachtin (neem extract, not neem oil) or botanical pyrethrum should also be effective. Synthetic pyrethroids are also commonly used in gardens for beetle pests.