This is the time of year when it is possible to see these rather exotic looking caterpillars. They were introduced to control the invasive plant, Leafy Spurge. Here, they are feeding on another non-native spurge, Cypress Spurge. We saw caterpillars in all instars, from tiny barely visible ones that look nothing like these, to very large ones (3 inches+). They also come in a variety of colours though the pattern remains the same.