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Search Results for: ramie moth

Damage to māmaki plant by moth highlights need for biosecurity

Posted on September 26, 2019 by Lissa Strohecker

The caterpillar of the ramie moth can be identified by its coloration — black with orange dots and white hairs — as well as its behavior — it “hisses” when approached. Report sightings to 643PEST.org. — Department of Land and Natural Resources photo

Last October, Keahi Bustamente was looking for rare snails in Olowalu Valley when he noticed a māmaki plant showing signs that something had been eating it. A quick look revealed the culprit was a black caterpillar. He plucked the unfamiliar insect in hopes he had found something new – perhaps a native species. Bustamente is an invertebrate biologist with the Pacific Cooperative Studies Unit. He works with the Department of Land and Natural Resources and spends his days scouring the forests for native land snails.

He couldn’t identify the larva and started asking colleagues on Maui and Oʻahu. An entomologist on Oʻahu guessed that it was from a ramie moth, never before found in Hawaiʻi, but to confirm the identification, Bustamente had to raise the caterpillar to the adult moth stage. A brown and black moth with a 3-inch wingspan emerged – it was indeed the ramie moth.

This new moth, Arcte coerula, is native to the Philippines and dines on plants in the nettle family (Urticaceae). The moth is large and a strong flyer, but it most likely arrives on our shores as a hitchhiker. Uninvited, this interloper is now munching its way through māmaki in our forests.

Māmaki is traditionally used in Hawaiian culture for medicinal tea and cordage. Increasing interest in the plant has led it being grown commercially for tea. In the forest, māmaki serves to stabilize streambanks. Māmaki supports over a dozen species of native insects, including leaf miners, moths, and beetles, and the Kamehameha Butterfly, which is reliant on māmaki.

Māmaki supports over a dozen species of native insects [that are] reliant on the plant itself. — Department of Land and Natural Resources photo

It’s not just māmaki that is at risk. The caterpillar of the ramie moth has been found on other plants related to māmaki, including maʻaloa (Neraumdia sericea), an endangered plant on the verge of extinction.

A few weeks after the Bustamente found the caterpillar in Olowalu, a native-plant grower reported finding it in Olinda and ʻUlupalakua; sightings from Waiehu, ʻĪao Valley and the mountains of West Maui soon followed. It quickly became apparent that the ramie moth was already too widespread to be removed from Maui.

The ramie moth is only the latest in a host of pest insects. Every year, over a dozen new insects arrive in Hawaiʻi. Some turn out to be serious invaders forever altering life in the islands. Little fire ants, coconut rhinoceros beetle, varroa mite, coffee berry borer, and naio thrip are recent examples. These troublemakers threaten native plants and animals, the function of our environment, our relationship with nature. Once established, they impact cultural practices, recreation and the livelihoods of the residents of Hawaiʻi, jeopardizing tourism and agriculture.

“At any point, some new plant or animal can come in and forever change Hawaiian ecosystems in a way we can never recover,” says Bustamente.

The arrival of yet another pest highlights the need for increased prevention efforts. The Hawaiʻi Invasive Species Council in cooperation with state and federal agencies developed the Hawaiʻi Interagency Biosecurity Plan. The plan lays out specific steps needed to improve biosecurity in Hawaiʻi. The plan needs legislative support and funding to be implemented.

It’s still too early to tell what the impacts of the ramie moth will be, but Bustamente and others are concerned.  “The caterpillar can hammer a māmaki plant,” says Bustamente, who has found over 100 individuals on a single plant. Even though it’s unlikely all will survive to adulthood, it’s during their caterpillar stage that they damage māmaki.  

If you have māmaki or other nettle-family plants in your yard, be alert to the threat of the ramie moth. Look for a black caterpillar (sometimes yellow) with bright orange spots and white hairs. Be careful not to confuse the ramie moth with the native Kamehameha caterpillar. The Kamehameha caterpillar is green for most of its life but is black immediately after hatching. The behavior differs as well – the ramie moth caterpillar rears up and spits to defend itself. Report sightings to the statewide pest hotline, either by phone: 643-6245 or online: 643PEST.org. You can learn more about plans to improve Hawaiʻiʻs protection against the arrival of new pests at the Hawaiʻi Invasive Species Council’s website: https://dlnr.hawaii.gov/hisc/plans/hibp/

Lissa Strohecker is the public relations and education specialist for the Maui Invasive Species Committee. She holds a biological sciences degree from Montana State University. Kia’i Moku, “Guarding the Island,” is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island’s environment, economy, and quality of life.

This article was originally published in the Maui News on July 13th, 2019 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

Filed Under: Kia'i Moku Column Tagged With: 2019, biosecurity, caterpillar on mamaki, mamaki pest, ramie moth maui

Protecting Māmaki From Invasive Species

Posted on May 28, 2021 by Serena Fukushima

The Kamehameha butterfly, the state insect of Hawaiʻi, is found nowhere else in the world and neither is the plant that feeds and supports the caterpillars as they develop into adults. Māmaki is the main host for this native butterfly, and supports other rare forest inhabitants such as the udea moth, happy-faced spider, and various species of Hawaiian tree snails. Māmaki is also an important food source for the endangered ʻalalā (Hawaiian crow).

A member of the nettle family (Urticaceae), māmaki lacks the stinging hairs of its continental cousins. Māmaki tea is revered as a general health tonic and has become a popular local product. Traditionally, Hawaiians have many uses for māmaki. The wood is used to make clubs and kapa beaters (iʻe kuku), and the inner bark is beaten to make a fine quality kapa. The fruits, seeds, leaves, and bark are used medicinally during pregnancy, for healing sores and wounds, as a mild laxative, and more.

  • Māmaki is important to a variety of native species such as the udea moth, happy-faced spider, Hawaiian tree snails, ʻalalā (Hawaiian crow), and Hawai’i’s state insect, the Kamehameha butterfly. Humans also use it for cultural, medicinal, and commercial purposes. Photo by Rick Barboza.

Māmakiʻs importance to native animals and Hawaiian culture is undeniable, so when a host of invasive species targeting it began to appear, conservationists, cultural practitioners, and community members sounded the alarm. You can help. Here are three invasive species that are threatening māmaki:

Ramie Moth
Originally discovered in 2018 in Olowalu Valley, the ramie moth’s presence on Maui (and now Hawaiʻi Island) represent the first record of this species in the United States. The larvae can grow up to ten centimeters in length are a vibrant yellow and black with bright orange-red spots, a black head, and thin white hairs. They may be seen feeding on a māmaki plant next to the larvae of the native Kamehameha butterfly, which do not have bright red spots on their side and possess thick, short spines on their bodies as opposed to the thin, long white hair of ramie moth larvae. Unlike the Kamehameha butterfly larvae, ramie moth larvae are aggressive, and if threatened, will rear up their head, thrash around, and even hiss and spit. If left unmanaged, ramie moth larvae will completely strip māmaki leaves, leaving only the thick veins of the plant behind. Ramie moths and their larvae have been observed in forests, residential areas, and are now being observed in commercial māmaki farms.

Māmaki Rust
Māmaki rust (Pucciniastrum boehmeriae) was first discovered on Hawaiʻi Island in 2013. The rust attacks māmaki and other members of the Urticaceae family by causing the leaves to drop early. Since the initial discovery, surveys at nurseries and botanical gardens throughout the state found no other cases, however, the rust is widespread in the Waiʻanae mountains and especially affects ōpuhe, another member of the native nettle family. At this time, māmaki rust has not been found on Maui and cases should be reported if encountered.

Polyphagous Shothole Borer
This tiny beetle is a little more than half the length of a grain of rice and has a reciprocol relationship with a fungus that it carries on its body. The polyphagous shot hole borer, or PSHB, damages māmaki by boring tunnels into the plant’s bark to farm its fungus food source. Although known to frequent over 30 other plant species, in Hawaiʻi, PSHB seems to prefer māmaki and ōpuhe, both members of the nettle family. Although little is still known about this beetle, it seems to prefer mamaki that are injured, reducing the plants chance of recovery by attacking it. Only documented on Hawaiʻi Island and Oʻahu, PSHB are difficult to spot and capture, but can be detected by the sawdust like frass it leaves at the base of the tree or the tubes outside of its tunnels. They sometimes come out of their tunnels in the afternoon and, if spotted, should be quickly captured for identification.

  • Report these invasive pests to www.643pest.org if you spot them on māmaki! (L-R) Ramie moth larvae (Photo:HDOA), māmaki rust on an endemic ōpuhe in the Waiʻanae mountains (Photo: K.Magnacca), and polyphagous shot hole borer (Photo: K.Magnacca).

With the eyes and ears of our community, we can all protect Hawaiʻi from invasive species. Kilo (observe) the māmaki plants you frequent, whether they are in your backyard or along a favorite hiking trail, and report any suspicious pests to www.643pest.org.

Serena Fukushima is the Public Relations and Education Specialist for the Maui Invasive Species Committee. She holds a bachelor’s degree in environmental studies and a graduate degree in education from the University of Hawaii at Manoa.  “Kiaʻi Moku, Guarding the Island”  is written by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that threaten our islands’ environment, economy and quality of life.

This article was originally published in the Maui News on May 8, 2021 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

Filed Under: Home Slider, Kia'i Moku Column Tagged With: 2021, 643-PEST, mamaki, mamaki rust, polyphagous shot hole borer, ramie moth

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Maui Invasive Species Committee (MISC)
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