Green veins

Green-veined White (Pieris napi)

Over the past few weeks, we've begun to see increasing numbers of Green-veined Whites (Pieris napi) in the garden. Some, like this pair, have even been stuck together, busily making more Green-veined Whites. It's not hard to see how they got their common name. From the top, they can look bewilderingly similar to Small Whites (which are known as "Cabbage Whites" in the US), but the green lines on their undersides are gratifyingly distinctive. Unlike the other butterflies I've profiled so far, this one is double-brooded. The offspring of one brood overwinters as pupae (no longer caterpillars, but not yet butterflies), emerging as adults from early April through June. These mate and lay eggs, and a second brood emerges as adults from mid-July into September. This second brood lays the eggs that hatch and develop as far as pupae, which then overwinter. Green-veined Whites are common and widespread across the British Isles, found everywhere except the highest peaks. They're drawn to damp areas with lush vegetation, where the larval food plants — a variety of wild crucifers — can be found. In our garden, the patches of Garlic Mustard likely fit the bill, at least for the first brood. These butterflies are most common in wetlands and damp meadows, along water courses, and in damper hedgerows and wood edges, but they clearly venture beyond those areas. Maybe, once we've put our pond in, they'll even stick around!