Hawai‘i Herald Columnist
Hawai‘i has only two native butterflies, or pulelehua – Vanessa tameamea (Kamehameha butterfly, Lepelepe-o-Hina) and Udara blackburni (Blackburn’s blue butterfly). These pulelehua are endemic, meaning they can only be found in Hawai‘i.
The Kamehameha butterfly became Hawai‘i’s official state insect in 2009 thanks to efforts by local elementary school students. Historically, these butterflies were found on all the main Hawaiian Islands, but their numbers are decreasing and are no longer common to see. Researchers at the University of Hawai‘i at Mānoa and the Department of Land and Natural Resources developed the Pulelehua Project to better understand the population size and map locations by using citizen science in collaboration with research surveys.
Kamehameha butterflies have orange and black top surface forewings with three white and light orange accents in the black area. The under surface of the hind wings are brown with pale tan splotches and with no eyespots. There are several non-native black and orange butterflies that can be mistaken for the Kamehameha butterfly in Hawai‘i, such as red admiral or painted lady butterflies. The difference is these butterflies usually have additional white spots on the top surface of the forewings. The gulf fritillary is another butterfly that is commonly mistaken for the Kamehameha butterfly. The gulf fritillary is mostly orange with black spots and the under surface has silvery spots. For picture comparisons of these different butterflies, please refer to the links below.
The Kamehameha butterfly lays many tiny solitary eggs on or under the leaf that hatch within a week. After hatching, the green caterpillars with black heads create a protective shelter by cutting a “C” shape along the leaf margin to create a flap under the leaf. The flap is secured in place with silk they produce. The caterpillars go through five instars (life stages) within 30 days. During this process it develops distinctive spines along the body and the head turns from black to brown or green. After reaching the last instar, it will form a chrysalis and emerge as a butterfly 12 days later. It takes approximately 45 days from the egg to become a butterfly.
The preferred host plant for the caterpillar is māmaki (Pipturus albidus), which is in the nettle family (Urticaceae). It is an excellent plant for tea and tends to grow in wetter areas with some shade. The adults feed on tree sap and flower nectar. Keep in mind that if you are interested in attracting butterflies, you will need the appropriate food source for both the adults (butterflies) and keiki (caterpillars).
Researchers are still trying to determine what threats are causing the decline of the Kamehameha butterflies. Predation by non-native birds is believed to be one of them as they eat the caterpillars before they are able to turn into butterflies. Ants may also be a predator of caterpillars. In addition to predator threats, the loss of habitat and food sources are threats to the population.
How you can help? The Pulelehua Project is asking the public who sees a Kamehameha butterfly, caterpillar, egg, or chrysalis to submit their photos and observations on iNaturalist.org. The data will be used to map the distribution of the Kamehameha butterfly and help determine why the population is being impacted. Further resources are: (Pulelehua Project) cms.ctahr.hawaii.edu/pulelehua/; (module 11 Native Butterflies of Hawai‘i – Identification, Natural History and Conservation, YouTube) youtube.com/watch?v=HsmZX_I-s_U.