The long-tailed blue butterfly (Lampides boeticus) is believed to have been accidentally introduced to Hawaii in the 1880s. Accidental or not, it wasn’t a good thing. Its common name, bean butterfly, gives a clue as to the problem. It damages a wide variety of bean and pea plants, both domestic and commercial.
These photos were taken on the Puna Coast Trail in Hawaii Volcanoes National Park. The plant is Vigna marina or beach pea, an indigenous plant that grows well in the harsh, exposed coastal area that the trail passes through.