Loved by monarchs - queens and butterflies alike. That's the claim to fame of these lavender or white gems of the crown flower. Pua kalaunu was a favorite of Queen Lili‘uokalani; a quilt patterned with the flower adorns her bed at Washington Place, as the long-lasting lei adorned her neck. Crown flower is also the host plant for the monarch butterfly, whose caterpillars gobble up the thick and wooly leaves. Known to botanists as Calotropis gigantea, this large shrub and member of the milkweed family first arrived in Hawaii in 1871. It produces a white, sappy milk that contains calcium oxalate and a cardiac glycoside, two reasons why the crown flower made #5 on the "Top Ten Inquiries About Plants to the Hawaii Poison Hotline."
Lei makers often soak the flowers in cold water to remove any sap, and bathe their hands in lotion before working with the flowers. Goggles may be worn to prevent the tearing and swelling that results from squirting flowers. A good sixty to seventy flowers are needed to craft a typical lei, so you may want to plant your own Calotropis gigantea. The plants are hardy, love the sun, and can grow in a variety of soils. Propagate by plunking a branch into water for a couple of weeks. After it roots, outplant and water well once a week. With luck, it might become the crowning glory of your yard.
These past few weeks, I have had the pleasure of witnessing the amazing metamorphosis of the vine hawk moth. It all began one night when a biggish blob fell from a shelf in my house, on which I had a Pentas (Pentas lanceolata) plant growing in a pot inside a large basket. Thinking it was a gecko, I moseyed on over to inspect it closer, when I realized it was a hefty and interesting-looking caterpillar. After a brief photo shoot of the critter, I went about trying to figure out what it was, so that I could rear it and watch into transform into a beautiful... something. I knew that caterpillars have specific plants on which they can feed, called "host plants," and that I couldn't just throw any old leafy green at it and hope that it would eat. Sure enough, I was able to whittle the search down, and it appeared that I had a vine hawk moth, Hippotion rosetta (hip-POE-tee-on roe-ZET-tuh), which has colonized Hawaii just recently, in the last fifteen years or so.
Identification can be tricky because the larvae of some caterpillars can change in appearance as they get larger and molt their cuticle; this typically occurs four or five times in most larvae of butterflies and moths. An interesting thing I learned from the Enchanted Learning website is that: "after the molt, while the new skin is still soft, they swallow a lot of air, which expands their body. Then, when the cuticle hardens, they let the air out and have room for growth." The "Insects of Hawaii" website gave information on what my caterpillar ate, and Pentas was one of the plants on which it dines, thus explaining the sad looking state of the plant on my shelf. I placed the caterpillar in a big mason jar with a screen lid and supplied the hungry larva with lots of Pentas leaves. In the morning, I was happy to see that it had eaten many of them, reassuring me that the identification was likely accurate. But later that day I found that it had stopped eating... and moving for that matter. Oh dear! Had I done something wrong? Was it alive? I gave it another day, and still nothing.
A few days later, my conscience was relieved: the caterpillar had pupated. All moths and butterflies undergo complete metamorphosis, a four-staged life cycle that includes the egg, the larva (caterpillar), the pupa, and the adult. My soon-to-be-moth was in that critical stage that seems like suspended animation, but in truth, it was undergoing a most dramatic transformation. A tough pupal skin had encased the caterpillar body. During this time there was little movement, though it would wriggle a bit if I moved it. Inside, the caterpillar body was being broken down, and cells called histoblasts were using the byproducts to build new tissue in the form of a moth. After a few weeks, the most miraculous event occurred: as I went to check on it, I noticed that the pupal casing had broken open. There, resting on the screen of the jar was a most beautiful looking moth, the vine hawk moth, hungry and fluttering its wings in anticipation of food. This moth species enjoys the nectar from Lantana camara, Duranta erecta and Ixora, all plants that are commonly found in Hawaii gardens and landscapes. After sharing it with some students, the moth was released to find its nectar plants, and to begin the cycle once again.
If you need anything, just give a hala. Seriously. This was one useful plant to early Hawaiians. The spiky leaves were (and still are) lovingly gathered, cleaned, dethorned, flattened and softened in preparation for weaving. The lauhala was literally woven into Hawaiian culture. Hats, mattresses, pillows, mats, ceilings, baskets, sandals, house thatching, sails, and fans were some of the items expertly crafted. The firm wood of the male tree made it suitable for use in the construction of hale. Medicines were derived from the aerial roots, leaf buds and fruits. Kapa was painted using the fibers on the ends of dried fruits. Beautiful lei were made with the hinano, the male flowers, as well as from the keys of the female fruit. Since the word "hala" also means faults, sins, errors, to pass (as time), lei made from the hala may be given at the end of a venture or to mark the passing of difficult times that have now "slipped away," making way for a new beginning.
Pu hala, Pandanus tectorius, is found around the Pacific. It is considered a canoe plant, but it is also likely that it found its own way to Hawaii, the buoyant fruits bobbing along on ocean currents and finding their way to tropical shores, where they take root. As with other plants that thrive in coastal regions, it is salt, drought, and wind tolerant. The common name, screwpine, comes from the leaves spiraling at the end of the branches. Numerous aerial roots support and anchor the tree, which is needed due to extensive spread (20 to 40 feet), but their resemblance to "legs" gives the tree the nickname "walking tree." The trees are either male or female, the male producing beautiful white bracts that wrap around small and fragrant flowers. The talc-like pollen was considered an aphrodisiac, and was used to scent kapa. Female flowers clusters develop into large globes of many wedges, called keys or phalanges, each of which hold around two seeds. Hala trees are found in cultivation and in the wild, though, like the weavers of lauhala, not as numerous as they once were.
When you spot your first Kolea this August, stop to consider the journey it has just completed. Unable to soar or rest on the water, this remarkable bird has just pumped its wings up and down for perhaps three thousand miles in its epic non-stop journey from the arctic tundra to the very patch of land you find it. It is likely the very same patch it patrolled during its previous winters here. Take a moment to marvel.
The eggs have been laid, incubated, hatched, and now the juveniles have been left to fatten up so that they, too, can make the journey in October. Scientists don't know how they accomplish this amazing feat of navigation, particularly since they have never made the flight before. And if, after that long journey, the young arriving in the fall cannot establish their own territory, it may mean an additional leg of the journey further south. Though they are shorebirds, kolea occupy a variety of territories, as long as they are open and have low vegetation: golf courses, parks, fields, and marshes will do. Once settled, they will spend the winter poking around for moths, caterpillars, cockroaches, and the like. They patrol their territories with both caution and a bit of daring, strutting quickly, then abruptly stopping and watching, rarely intimidated enough to fly off. In the spring, their diet will expand to include berries, seeds and leaves prior to their return trip in late April to May. Just before they embark on that return journey, they'll sport a gorgeous summer breeding plumage: a dark underbelly and face piped with a racing stripe of white. I for one am inspired by the fortitude of this delicate little bird.
The endangered Hawaiian stilt, or Ae'o (Himantopus mexicanus knudseni) is a beautiful sight to behold in Hawaii's wetlands and marshes with it's dark upper body offset by white underneath and up through the neck and near the bill. It has red eyes, with a variable white dot above. The legs are pink, and, um yeah, they're pretty long. It shares it genus Himantopus with four other species that look quite similar. According to the Cornell Lab of Ornithology, birds of this genus "have the second-longest legs in proportion to their bodies of any bird, exceeded only by flamingos." Ae'o are well adapted to their environs: the long legs help them to gracefully and slowly navigate the shifting surface of the wetlands, and the legs can bend backward to bring the body nearer to the ground. The slender bill is suitable for probing the muddy waters for aquatic invertebrates, or for having a go at small fish. A long and flexible neck helps with the hunting techniques as well.
They are quiet while hunting, but can emit a sharp call in flight, or when defending their nests, which are often shallow depressions dug in the ground. Three or four eggs are typically laid, and both male and female will share in the incubating and brooding of their young. Ae'o are known to be fierce defenders of their nests, and will dive bomb intruders, or feign a broken wing to divert the intruder's attention from the nest (I haven't seen the Ae'o do this, but I have seen killdeer put on the broken wing act, and it is pretty convincing). Young stay with their parents for several months. Places to see Ae'o here on Oahu include Hamakua Marsh and at Kahuku Point on the James Campbell National Wildlife Refuge.
Over the past few months, I have watched as more and more of these little hangy-things have grown in number on one of my plant containers in the backyard. They're different from the hangy-things in the laundry room, which are smoother and thinner, and probably belong to a case-bearing moth. No, these are spikier and more grassy. So a trip to the library and a bit of searching, and I think I have cracked the case, pun intended (thanks to Jamieson & Denny's Hawaii's Butterflies and Moths)!
It's the home of the caterpillar of the bagworm moth, Brachycyttarus griseus in the family Psychidae. First reported in Oahu in 1984, the species is well established in South East Asia. The male moth is about one and a half centimeters in length, not so big, and the female is wingless. She's got it in the bag....living her entire life there, never to leave. The male impregnates her while she's in her protective casing and then she releases her eggs to the ground. Upon hatching, the little caterpillars eat grass, such as Paspalurn conjugaturn and Zoysia pungens, and immediately get to work constructing their casings. They drag them behind as they feed, and enlarge them with bit of grass and webbing as they go. Once they are about one centimeter in length, the larvae climb up to a spot, say, on a plant pot, the eave of a roof, or a garden shed, and attach themselves to pupate. Only the males will leave the casing, when they go in search of a mate. They are said to be pretty harmless, though I did find a website that said they were pests of basil and lemongrass. So, now the caterpillar is out of the bag.
Today's post is intended to give voice to the native tree snails of Oahu, genus Achatinella. I hope you become as enamored as I am with these "jewels of the forest." Once abundant throughout Oahu, this genus of forty-one species of endemic, nocturnal snails has suffered from a "perfect storm" of events that has caused the loss of at least half to extinction, with the rest endangered or critically endangered. Those that remain cling to life on isolated ridges in the Ko‘olau and Wai‘anae ranges. They are small wonders indeed; all species are just around two centimeters long, with beautiful coloration and patterning that varies from species to species. As their name suggests, they are arboreal, but do little damage to the native trees that they prefer. Instead, they dine on a fungus that grows on the leaves, which may actually help the trees to photosynthesize. Achatinella young develop in eggs inside the mother, then are born live. They live for as many as ten years, but their reproductive capacity is low. For example, Achatinella mustelinadoes only produces four to seven offspring a year, and this occurring only after sexual maturity is reached, between ages three to five.
As you can imagine, their slow growth rate and fecundity would make them a vulnerable species. Recovery would be extra tough after any event that would reduce their numbers. And there have been several. For years they were over-collected for their beautiful shells. Add to that the loss of much of their native habitat to farming and other human activities. If that isn't enough, we opened the door to one of their most dreaded predators: the carnivorous rosy wolf snail. Introduced in 1955 to combat the Giant African snail, the rosy wolf snail decided that the smaller, native snails tasted a lot better. Rats have also taken their toll on the population. But instead of throwing their hands up in the air, some have come to the snail's rescue, including The Hawaiian Tree Snail Conservation Lab, whose main goal is to care for rare Hawaiian tree snails and breed them in captivity. Nine species of Achatinella are under their loving care. Also fighting the good fight is the U.S. Fish and Wildlife Service and the Oahu Army Natural Resources Program (OANRP), who are involved with the effort to build snail refuges with elaborate "exclosure" systems to keep predators out. I, for one, am grateful for their efforts to save these jewels, and for the important lesson that sometimes, big things come in small packages.
welcomes you to visit with the all the wonderful flora and fauna that we share this lovely aina with.