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Ramie Moth

The ramie moth is a destructive caterpillar that can completely defoliate native māmaki. This caterpillar was first discovered in November 2018 on Maui where it was destroying māmaki plants. Since then, it has spread to the Big Island and was found on the east side in November 2020. This is the first record of this pest in the United States. It’s known to feed on members of the nettle family (Urticaceae). Besides harming the māmaki plant, this caterpillar also poses a threat to the native Kamehameha butterfly as it competes for the same food resources.

The young ramie caterpillar will start by chewing holes in the middle of the leaf and create even larger gaps as they grow, leaving only the main veins. Kamehameha caterpillars start eating from the edge of the leaves. Young Kamehameha caterpillars will fold over the edges of the leaf to make a tent for protection.

Photo of Kamehameha caterpillar by Forest and Kim Starr

Adult ramie moth

Ramie Moth: appearance

Ramie moth (RM) eggs are about 1mm in diameter and are a clear-white color. The eggs are laid individually on the underside of leaves.Â Kamehameha butterfly (KB) eggs are more brownish in color. The first instar of RM caterpillars are green and black. As they get larger, they change color to become yellow and black with red/orange spots and thin white hairs. There is also a black variant of the RM caterpillar, but it still has the iconic red spots and white hairs. The RM caterpillar can look very similar to the KB caterpillar and they are found on the same plants, so it is important to make a positive identification before taking any action! Young KB caterpillars also have black-colored heads, but they turn green or brown as they get older.

Unlike KB caterpillars, the ramie caterpillars are aggressive…at least, relatively aggressive for a caterpillar! When disturbed the caterpillar may lift its head and start wiggling around, and might even vomit a green fluid. These actions are to dissuade predators but are not displayed by KB caterpillars.

The adult ramie moth is about 3 cm long with a 6-9 cm wingspan. It is mostly brown, with black markings on the scalloped wings. Hindwings have silvery-blue markings. They can be challenging to identify, so please send a picture of your suspect caterpillar to BIISC or your local HDOA or CTAHR office for identification.

Be careful when moving māmaki and olonā plants, and do not move them interisland. Always inspect your plants before moving them.

If you see a ramie moth caterpillar, please capture it and report it to 643-pest.org.

Ramie Moth HDOA Pest Report w/ pictures

How to ID a Kamehameha Butterfly

Mystery Invader Identified: Phenax hirtus

A critical part of the work we do at BIISC is looking for new, potentially damaging, arrivals, In late 2017, BIISC botanists collected a mystery plant on a trailside early detection survey on the Kona side near the Makaula-O‛oma State Forest Reserve. It was at first easy to overlook, with no eye-catching characteristics to make it stand out from the lush greenery around it. However, trail users had reported its aggressive tendency, and its persistence even after they tried to control it. The BIISC team realized that this plant did not match any known introduced or native species on the island, and observed that it was reproducing naturally – and quickly – throughout the area: an alarm bell indicating a potential invasive species.

However, before declaring a new species invasive, careful investigation must be done – and the first step is ensuring a definitive identification of the organism. But this seemingly simple question became more vexing as the team pored over botany records: just what WAS this plant? With hundreds of thousands of plants in the world, many with little published information available, plant ID is not an easy task. The team reached out to plant experts on the island and across the state, but no one recognized this one. Samples and photos made their way to various botanists until in 2020 a Smithsonian botanist, working with colleagues from Europe, was able to pronounce that a little-known, low-profile shrub from Central America, Phenax hirtus, had somehow arrived in Hawai‛i.

Phenax taking over the understory

Phenax leaves and growth pattern

Hogging Space

Like another recent invader, the Queensland Longhorn Beetle, Phenax hirtus wasn’t known to be a pest anywhere else in the world before it appeared on the Big Island. It is unknown how either arrived here, but most likely it was a “keiki form” (larvae in the case of the beetle, seed for the plant) as an accidental stowaway, quietly arriving in some kind of soil, plant material, or packing crate. These sleeper species will often quietly proliferate and spread, unnoticed until they begin to cause a problem. This can make it difficult to enact a successful eradication plan; without previous research, we don’t always know how to control the pest. Information about the species’ life cycle, reproductive strategies, seed viability, climate tolerance limits – all can be critical to making sure control efforts are effective.

Phenax hirtus has many of the classic characteristics associated with invasive plants: it is shade-tolerant and can grow in undisturbed vegetation, including under a native forest canopy. It has a climbing nature, able to pull itself up over other vegetation to seek light and space. It even finds a way to grow amongst aggressive Himalayan (kāhili) ginger – a known “space hog”! Seeds are tiny and can spread easily on wind or water.

Phenax hirtus overtaking residential landscaping. (Photo: JB Friday)

BIISC crews are working now to control outlier populations of Phenax in the Kaloko Mauka community where it was found and limit it from continuing to spread. Big Island residents are also being asked to be vigilant and take pictures of any suspect plants in other areas of the island. It is a nettle, the same large family as the native māmaki, so the leaves are similar, but generally skinnier and more green (not so much of the reddish veins that are generally present in māmaki). The best way to tell them apart: māmaki produces seeds in a distinctive fleshy white fruit at the end of the leaf node, while Phenax will have a dry brown ball of seeds.

Mamaki fruits (left) are fleshy and white, while Phenax fruits (right) are dry and brown. (Forest & Kim Starr; JB Friday).

In today’s world, some invasive pests are nearly household names in dozens of countries: Asian longhorn beetle, spotted lanternfly, red imported fire ants, giant hogweed. These pests make headlines the minute they appear in a new area. But Hawai’i, while at risk of these notorious invaders, is also uniquely vulnerable to taking a bad turn to invasive behavior. Life in Hawai’i evolved in isolation over millions of years, with a barrier of 2500 miles of open ocean dissuading colonization by new life forms. Biologists estimate that before human contact, a new species established in Hawai’i only about once every 10,000 years. Without the fierce biological competition and predation found on an African savannah or South American rainforest, our native species evolved without many of the defenses and protections that their continental counterparts had long developed.

The year-round temperate weather, novel native ecosystems with open niches, and multiple climate zones of the islands all provide opportunities for introduced species to become problematic in Hawai’i. With more introduced species reaching our shores today than ever before, it is critical to be vigilant and keep an eye out for anything new that appears unexpectedly, potentially posing a problem.

Mamaki leaves (left) tend to be more oval with reddish petioles while Phenax leaves (right) tend to be more narrow and green throughout. Photos: Forest & Kim Starr; JB Friday

Pampas Grass Eradicated

BIISC is happy to share some good news: one of the most notorious invasive grasses in Hawai‛i, pampas grass, has been eradicated from the Big Island! Both species of pampas grass known to occur in Hawaii, Cortaderia jubata and Cortaderia selloana, have been removed, and monitoring continues for any keiki that might appear at the sites of previous known locations.Â

Both species of pampas are on the state’s Noxious Weeds list. The South American plant was shipped around the world in the late 1800s, popular for the showy plumes used in fashion and decor. It grows in large clumps, with feathery white or lavender plumes growing up to 10 feet tall. As people planted it across the Pacific, it slowly began jumping from planting sites and spreading out into natural areas, disrupting native ecosystems in places like New Zealand, California, and here in Hawaii. It is now widespread on Maui, and because it is adapted to fire in its native range poses a significant threat as a fuel for wildfires.

Pampas grass is a noxious weed.

BIISC staff controlling pampas grass.

Efforts to eradicate pampas grass

When the Hawai‛i Island eradication effort began in 2007, the plant was mapped in over two dozen locations including several places in Volcano and on the West side of the island. Although most of the adult plants were removed early in the eradication timeline, Joel Brunger, our field operations supervisor, points out the challenges of surveying for other pampas grass clumps near an adult plant: each grass clump is capable of producing thousands of lightweight seeds which are carried by the wind as far as 20 miles from the parent plant!

BIISC relied heavily on reports from the public about potential pampas sightings, carefully tracking down and identifying each plant to locate any previously undiscovered populations. Removal of the plants by BIISC crews took time, as permission from property owners was required for most of the sites. Locating and contacting property owners can pose a significant challenge for our control efforts, but overall most people were cooperative and eager to support the removal of an invasive plant from their property. The Hawaii Department of Agriculture assisted with securing access for removal of the noxious weed where permission was difficult to obtain. Finally, in 2019, the last known population of pampas was removed, and native māmaki was planted in its stead. BIISC botanists continue to monitor the area to catch any keiki plants that may spring up.

An Ongoing Risk

Despite the razor-sharp leaves and potential for fueling wildfires, pampas grass is still sold throughout the world in the horticultural trade and used for landscaping. During the course of the eradication effort, BIISC developed the Plant Pono program, a nursery endorsement and education effort aimed at stopping the sale of invasive plants in Hawaii. Pono-endorsed nurseries voluntarily pledge to sell only non-invasive â€œponoâ€ plants. There have been no sales of pampas grass in Hawaii for the last several years, although seeds purchased online continue to be a risk for introductions of invasive plants.

If you spot an online seller promoting pampas grass and allowing shipment to Hawaii, pass the info along to us! Often, just informing a well-meaning grower outside of our state about the potential risks is enough for them to stop any shipment of the plant to the islands.

BIISC takes the lead on early detection and rapid response to new invasive plant species, which means our teams search for new species of plants on the island and target them for eradication when necessary and possible. Efforts to control many of our most notorious widespread invaders like miconia, albizia, or strawberry guava came too late, well past the time when it was economically possible to remove those species from the island. There is only a short window of time when an invasive species can feasibly be eradicated. Once that window has closed, control strategies switch to other efforts, like containment, or at the furthest point, exclusion only from high-value areas.

Currently, BIISC is targeting several invasive plant species assessed to be within the “window of eradication.” These species are not yet widespread, and BIISC crews are working to remove them now so that they will not become the albizia or miconia of the future. Visit our target species page to become familiar with our target species, and be sure to report any new or strange plants you encounter!

Pest Alert: Banana Lacewing

UPDATE: As of 2024 Banana Lacewing has been found on the Big Island.

The Hawai‛i Dept. of Agriculture has announced a new pest called the Banana Lacewing Bug (Stephanitis typica). This pest has a variety of hosts, not just bananas. As of June 2020, this lacewing has only been found on O‛ahu. Please report any new sightings to the Hawai‛i Dept. of Agriculture Plant Pest Control.

Hosts:

African Oil Palm (Elaeis quineensis)
Bananas (Musa spp.)
Camphor laurel (Cinnamomum camphora)
Cardamom (Elettaria cardamomum)
Champedak (Artocarpus integer)
Coconut (Cocos nucifera)
Colocasia sp.
Edible Ginger (Zingiber officinale)
Flowers (Alpinia spp.)
Heliconia spp.
Plantain (Musa x paradisiaca)
Soursop (Annona muricata)
Tumeric (Curcuma longa)

How did QLB get here?

In August 2019, a resident from Puna submitted logs to the state Department of Agriculture office in Hilo. Those logs were the remains of a moringa tree, another victim to the voracious appetite of an Acalolepta aesthetica, which has come to be known locally as the Queensland Longhorn Beetle (QLB). On that morning, HDOA entomologist Stacey Chun piled the logs in the corner of the insect containment unit and reluctantly added moringa to the growing list of tree species being attacked by QLB. Already, the insect had been confirmed in several kinds of trees, including citrus, kukui, breadfruit, and cacao. It was the cacao farmers who had first raised the alarm on QLB in 2018, when growers noticed healthy, producing trees suddenly devastated by a mysterious insect.

The case of A. aesthetica illustrates the difficulty of managing new invasive pests. Although it was first identified from a sample turned in to the HDOA office in 2009, no subsequent specimens were reported for several years. The Coordinating Group on Alien Pest Species (CGAPS), which provides tools and guidance for invasive species response in Hawaii, has estimated that one new insect species per day arrives at Hawaii’s ports. Most of the creatures that get here accidentally are individuals who will not survive in their new environment. Some will find their way and naturalize, but never rise to notice because they don’t cause much disruption to the world around them. But a handful will become pests that make headlines: coqui frogs, little fire ants, semi-slugs, two-lined spittlebugs. These are the introduced species that thrive in the Hawaiian environment, free from the predators and diseases that kept them in check in their home ranges, and able to exploit the environmental niches left open in an isolated island ecosystem.

Queensland Longhorn Beetle captured in Puna.

Moringa logs dropped off at HDOA in Hilo after the tree was attacked by QLB.

When a few more of the new longhorn beetles turned up in 2013, it was clear that the insect had found a way to survive and breed in Hawai‛i. It was not clear what this meant. An investigation into the insect’s background revealed little, only that it was from Queensland, Australia, and not known to be living anywhere else in the world – until it reached Hawai‛i. In Queensland, lush and verdant tropical forests surround landscapes of agricultural production, and never was this beetle reported as a pest. As just one of dozens of Cerambycid (longhorn) beetle species found in Queensland’s forests, this dull brown, cockroach lookalike didn’t particularly stand out. Very little was known about its life cycle or habits, or even which tree species it favored in its home range.

How it arrived in Hawai‛i was even more of a mystery. From genetic tests done by Dr. Sheina Sim at the USDA Agricultural Research Service in Hilo, it is clear that all of the QLB in Hawaii are descendants of the same line, meaning there had been only one introduction event. But due to the Jones Act, Hawaii receives very few commodities directly from other countries. Most goods crossing the Pacific must first head to the mainland to a designated international port, then be shipped back to Hawaii from there. No direct shipments from Queensland appeared to account for the insect arriving in Puna.

QLB larvae in dead logs. Photo courtesy S. Chun, HDOA.

QLB life stages (L-R): pupa, adult, and larva

Clues could be found in studying a closely related member of the QLB’s family, known as the Asian Longhorn Beetle (Anoplophora glabripennis), or ALB. Unlike its Queensland-based cousin, the ALB is a known problem-maker worldwide. In North America, where it was first spotted in 1996, costs of damage and control associated with ALB are now at nearly $1 billion. The ALB is so devastating that some European countries have taken the approach of killing every susceptible tree within a half-mile when a single insect is found.

The arrival of ALB in the 1990s coincided with the opening of direct trade between the US and mainland China, and the source of the introductions was deduced to be untreated wood packing materials that delivered hidden larvae along with their cargo. Because the behavior and life history of ALB appeared similar to Hawaii’s new and unwelcome guest, researchers hypothesized that it was possible QLB could have arrived here the same way. But was it possible the larvae could have survived a lengthy trip across the ocean and halfway back again?

A large hole in a moringa log where an adult QLB emerged. Photo: S. Chun, HDOA.

QLB have a brown, velvet-like appearance and have spines on their “neck”

The moringa logs in Stacey Chun’s HDOA lab offered up an answer to that question. Nearly eight months to the day after the logs were set aside, all but forgotten in the QLB insectary, a live adult emerged from the dried wood in April 2020. It had taken that larvae nearly eight months to develop to full adulthood (previously, Chun had recorded adult emergence as soon as 3 months). Eight months was more than enough time for a clutch of insect eggs to have traveled halfway around the world, unnoticed as they slowly developed inside of their wooden nest, to finally emerge as full-grown adults in an unsuspecting new home.

QLB and ALB are not the first of their kind to move into new territories via untreated wood, and unfortunately, they will likely not be the last. As humans enjoy the convenience and opportunity that new technology and increasing global traffic have afforded us, we must also contend with the downsides, one of which is the accidental movement of species into places where they have the potential to cause great harm. In the early aughts, in response to multiple infestations of new pests, the US and many other countries adopted a set of requirements that wood packaging material be certified as properly treated to kill pests. These rules were phases in and not fully implemented for several years, which is possibly the window during which QLB came into Hawaii. Subsequent research has also found that not all wood-boring insects are equally susceptible to the prescribed treatment methods and that the quality and efficacy of the packing wood treatment can vary between manufacturers, so even with enhanced regulations Untreated or inadequately treated wood remains a potential risk.

More information about the Queensland Longhorn Beetle can be found he r e.

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