Maui Invasive Species Committee (MISC)

Illegal dumping risks spreading invasive species

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Coqui frogs, like this male guarding his eggs, take advantage of man-made materials for shelter. Illegally dumping rubbish can spread pests like coqui and make removing them more difficult. Photo by Maui Invasive Species Committee.

The evening of July 24, 2018, a Maui resident living near the Five Corners area of Haʻikū heard something she did not recognize as a normal sound for her neighborhood: the 2-note call of invasive coqui frogs. “I was in shock,” she says. “All the sudden there were 5-10 coqui frogs near my house.” She reported the frogs to the Maui Invasive Species Committee (MISC) and worked with neighbors to pinpoint the frogs’ location in a gulch adjacent to a nearby pasture.

When crews arrived a few days later, they indeed found coqui frogs spread across a quarter acre. They also found a rubbish pile with tires and plywood. “Given that there were no frogs, then suddenly ten—that’s too many to have jumped onto a car and been moved to the site,” explains Abe Vandenberg, MISC Coqui Coordinator. “The more likely scenario is that there was a clutch of eggs moved in the rubbish pile.”  Coqui frogs hatch out from their eggs as tiny froglets, unlike other frogs that go through a tadpole stage that requires standing water.

Coqui are an introduced species to the Hawaiian Islands. Without the predators like snakes that keep them in check in Puerto Rico, they reach unnaturally high densities that are 2-3 times higher here in Hawaii than in their native habitat. In turn, they impact insect populations and nutrient cycling. But their mating call is what drives control efforts – males call “co-qui” from dawn until dusk in a piercing cacophony that disrupts sleep.

Unfortunately, the Five Corners situation is not unique. Even in the early days of coqui control efforts on Maui, roadside dumping factored into the amphibians’ spread. A vehicle abandoned in Māliko Gulch was the likely vector of frogs to a salvage yard in Haʻikū. As the coqui population increases on Maui, so do the instances of coqui moving in green waste and trash.

In the last year, illegally-dumped rubbish has been the vector for at least five introductions of coqui that MISC is aware of.

 Little fire ants are another invasive pest that is known to spread through the movement of green waste and debris. Green waste facilities are monitored for these pests to reduce the risk of spread but illegal dumping can circumvent these safe guards.  Photo by Maui Invasive Species Committee.

More often than not, the frog-infested trash is dumped in gulches – a difficult and dangerous place for crews to access and remove the noisy invaders.

It’s not just coqui frogs hitchhiking in trash and yard waste. On Hawaiʻi Island and in Tahiti and Guam, little fire ants have been spread through green waste. On Maui, MISC has worked with the owners of properties infested by little fire ants to address this threat, but undetected populations of pest ants most likely still exist. On Oʻahu, the larvae and eggs of the palm-killing coconut rhinoceros beetle (CRB) develop in coconut mulch, so preventing the spread of green waste is the most important task for crews working on the CRB Response Team. Coconut rhinoceros beetles are killing coconuts and other palms on Oʻahu and have not yet been reported from other islands.

Coconut Rhinoceros Beetles (CRB) lay eggs in mulch and so stopping the movement of infested debris is a priority for the CRB teams on O’ahu. Photo by U.S. Army Garrison Hawai’i. 

When yard clippings and mulch are properly handled, green waste is less of a threat. The temperature of a managed compost pile reaches 150 degrees Fahrenheit, enough to kill weed seeds and many invasive pests and their eggs. Additionally, bringing green waste to a central location allows for monitoring. Green waste sites on Maui are regularly surveyed for the presence of little fire ants.

People who are tempted to dump their rubbish illegally may not realize that the impacts of their actions can be catastrophic. Often, illegal dumping attracts more dumping. The tangle of trash provides ample sites for pests to hide out and avoid treatment. You can help. Properly dispose of waste at the landfill, green waste facility, or compost it on site. Report illegal dumping to the Maui Police Department, at (808) 244-6400, and to the State of Hawaii Department of Health at (808) 984-8230.

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 on May 13th, 2018 as part of the Kia’i Moku Column for the Maui News.

Introduced songbirds can be invasive in Hawai’i

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There are other birds not known to be on Maui that should be reported immediately if seen. The red-vented bulbul is one such species; — K. HARI KRISHNAN photo

In March of 2018, a cluster of reports from Maui residents and visitors of White-rumped shamas in West Maui came in on the online birding database, eBird. The Maui Invasive Species Committee and other organizations had received reports before, but the frequency of reports caught the attention of Chris Warren, who works with the Maui Forest Bird Recovery Project. These birds weren’t known to be widespread on Maui.  White-rumped shamas are not native to Hawaiʻi. These introduced species have established breeding populations on Oʻahu, Molokaʻi, Lānaʻi, and Kauaʻi, but only scattered sightings had been reported on Maui in the past. No new invasive species is a welcome addition to our fragile ecosystems here on Maui. Warren and his team went to Kapalua and the Honolua area to investigate.

“Pretty soon it was evident that there were more than just a few birds out there,” says Warren. This wasn’t a case of a lone bird—the team found shamas in streambeds and forested areas from Napili to Honolua Bay, but the full extent of their population is still unknown.

White-rumped shamas are native to western Indonesia, southern India and southwestern China but have been introduced elsewhere as a result of their popularity as cage-birds and songsters. Here, their diet consists mainly of small insects that they pounce on while in the underbrush. According to Warren, there are other introduced birds that may pose a greater threat to native birds than the shama but what has resource managers concerned is that a bird new to the island went unreported for so long. “Our native birds are already at a tipping point, the last thing they need is another competitor,” he says.

White-rumped shamas are part of the host of bird species brought to Hawaiʻi during an era of bringing in song-birds. By the turn of the 20th century, avian malaria and introduced predators had already brought native Hawaiian bird populations to low levels. Residential gardens were quiet but for the squawking of mynas and calling of doves. The socialites of Honolulu formed garden clubs for the purpose of importing song-birds—which only put added pressure on native ecosystems. From the 1920s up until the 1960s, when the practice was restricted, these garden clubs introduced many species of songbirds. Not all of these birds became established, but many did, and the musical White-rumped shama was among them.

Shamas were first released in Kauaʻi in 1931 and then in Oʻahu between 1938 and 1940. Those 89 birds then spread, reaching Molokaʻi in 1997 and Lānaʻi by 2009. They may have crossed between the islands on their own, but it’s also possible that humans helped them spread inter-island.

Warren and his colleagues are not exactly sure how far the shamas have spread on Maui. With the help of other resource management organizations, Maui Forest Bird Recovery Project is working to determine the distribution of these singing flycatchers. You can help!

  • White-rumped shamas are 9-11 inches long, about the size of a northern cardinal.
  • They have long tail feathers and spend much of their time in the underbrush.
  • Males have a glossy bluish-black back and head, a chestnut brown belly, and white patch feathers under their tail. Females have a tan head and back with chestnut belly.
  • Their song is impressive, both in range and volume, making them hard to miss.
  • Find information with photos and recordings, online: The Cornell Lab of Ornithology – White-rumped Shama. Report sightings, with a photo or recording through the online pest reporting system, 643PEST.org.
The red-vented bulbul is not known from Maui and should be reported immediately if seen. This bird resembles a cardinal but the head is completely black and it has a distinctive red patch on the underside. Bulbuls are serious agricultural pests on other islands. Report any sightings to 643PEST.org. — K. HARI KRISHNAN photo

While the white-rumped shama is likely here to stay, however, there are exotic bird species present on other islands that have not yet reached Maui. Red-vented bulbuls found on Oʻahu are one example: they are voracious fruit eaters and serious agricultural pests that quickly dominate the landscape.

To keep a new invasive species from becoming established, finding it early is essential. If you see something new in your yard, birds notwithstanding, take a few minutes to report it on the statewide pest reporting system. Either call 643-PEST(7378) or use the online report form, 643PEST.org.

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 on May 13th, 2018 as part of the Kia’i Moku Column for the Maui News.

Natural enemies could tame invasive Himalayan ginger

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Though not invasive in India where it is native, Himalayan ginger can completely transform a Hawaiian rainforest like it has in this section at 4,000-foot elevation above Haiku. Inset: Ginger fruits are spread long distance by birds and rats. FOREST and KIM STARR photo

The subtropical rainforests in the foothills of the Himalayan Mountains are amazingly diverse. In sections of India and Nepal, the forests are similar to Hawaiian rainforests in both temperature and rainfall-but the flora and fauna are radically different: this is the land of elephants and red pandas; 600 species of butterflies live here and over 400 species of orchids. But amongst the exotic plants there is one

The fruit of Himalayan ginger is a tasty treat for non-native birds, but this means the seeds are spread throughout the forest. Photo courtesy of Forest and Kim Starr.

that might be familiar to residents of Hawai’i-a yellow-flowered ginger that covers vast sections of Hawaiian rainforests.

Himalayan ginger, Hedychium gardnerianum, is native to the Himalayan foothills. There, it evolved over millennia supporting a diversity of species: the sweet nectar is a food for the long-tongued butterflies of the region and the plant lives in harmony with the species that surround it. Yellow flower stalks dot the landscape amongst hundreds of other orchids, gingers, ferns, and trees.

But in Hawai’i, Himalayan ginger dominates the landscape-growing fast and paving its way into the forest in an unrelenting march.

“Himalayan ginger displaces critical native vegetation layers, limits canopy tree recruitment, and hogs water resources in their massive rhizomes (roots). As it takes over and forms monotypic stands, it negatively impacts native flora and fauna, including Hawai’i’s unique arthropod complex and the Hawaiian honeycreepers,” says Alison Cohan, director of the Maui Nui Forest Program with The Nature Conservancy (TNC).

Introduced as an ornamental, Himalayan ginger escaped backyards and began invading rainforests of East Maui in the mid 1950’s. With seeds dispersed far and wide by birds and rats, the weedy plant spreads by leaps and bounds into the forest. Today, much of the mid-elevation rainforest of East Maui is a patchwork of native forest and alien ginger. But there is a lot left to protect: many ginger-free areas remain, including most of West Maui.

Ginger is a formidable foe and removing the plant is no simple task. Roots pave the forest floor like asphalt and every part of the rhizome must be removed. Bagged rhizomes take years to decay and if there is the slightest hole in the bag, hardy shoots emerge. If using herbicide, every portion of the root has to be treated. Plants on steep slopes and cliffs are inaccessible and impossible to remove until the weight of the water-logged roots causes entire sections to collapse in a landslide.

Why would ginger be a pest in one place but not another?

Djami Djeddour, weed biocontrol scientist with the Centre for Agriculture and Bioscience International, inspects a lone Himalayan ginger plant in India while searching for insects and fungi that live on the plant where it is native. These insects may be responsible for keeping the plant in check. DJAMI DJEDDOUR photo

The answer to that question is on the minds of resource managers in Hawai’i as well as New Zealand, Australia, and South Africa where the plant is invasive. With funding from organizations like TNC and the Hawai’i Invasive Species Council, research scientists traveled to India and collected insects and fungi that live on Himalayan ginger hoping to discover what keeps the fast-growing herb in balance there. An effective natural enemy could be a game changer for Hawai’i.

An effective natural enemy wouldn’t eliminate the plant, just bring it into harmony with the surrounding environment, much like it is in India and Nepal.

One of the most promising insects is a Cloropid fly that lives only on Himalayan ginger. The larvae live inside the stem stunting the growth and reducing flower production. Ginger natural enemies may be ready for release in New Zealand soon, promising progress for Hawai’i.

“The Nature Conservancy had been doing ginger work in Waikamoi for over 30 years, systematically conducting ginger control—containing the core population at the western edge of Waikamoi and eradicating outliers in native forest,” explains Cohan. Crews with Haleakala National Park work on the flowering pest in Kīpahulu Valley but the plant is widespread and thrives unchecked in wet places throughout the state.

There are ways you can help. Consider what you call the plant: though known for years as kāhili ginger, a pest destroying the rainforest does not deserve a moniker reminiscent of Hawaiian royalty much less one that might suggest that it belongs here. Perhaps call it toilet-brush ginger, as suggested by Pat Bily of TNC after years of removing it. Do not plant Himalayan ginger in your yard and remove it from your property before it spreads. Finally, participate in The Nature Conservancy’s quarterly volunteer trips removing ginger from Waikamoi Preserve. Contact hike_waikamoi@tnc.org if interested.

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 April 8th, 2018 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Native species recovering at Mokio Preserve on Moloka’i

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Jay Penniman of the Maui Nui Seabird Recovery Project sets up an acoustic monitor near the Laysan albatross decoys at the Mokio Preserve on Molokai. The speaker in the foreground broadcasts mating calls for the very rare Laysan albatross during the day, while acoustic monitors record nighttime activity from other seabird species like the wedge-tailed shearwater. — BUTCH HAASE / Molokai Land Trust photo.

On the windswept, northwestern corner of Moloka’i there is an old cattle pasture that, until recently, was covered in kiawe, buffelgrass, and lantana. But underneath the invasive plants, seeds of native species lay waiting, ready to grow if given the chance. Endangered Hawaiian insects found refuge in pockets of the sea cliffs. Seabirds patrolled the coastlines. Their wait may be over.

In 2008 the Molokaʻi Land Trust began to manage Mokio, five miles of coastline between the state-owned Ilio Point and The Nature Conservancy’s Moʻomomi Preserve. This former pastureland was never developed and is rich in both cultural and biological resources. Seasonal wetlands support the largest population of an endangered fern, ʻihiʻihilauākea, or four-leaf clover fern, in the State. Adze quarries and pre-contact Hawaiian housing sites remain relatively intact. It is a promising seabird nesting habitat, already in use by the koaʻe ʻula and koaʻe kea (red-tailed and white-tailed tropicbirds) that nest in the cliff faces and noio (black noddy) that raise their young in caves. But years of cattle and deer traffic have taken a toll on the native plant community.

The first step in restoring the area: fencing out large grazing animals. “Sixty acres are fenced,” says Butch Haase, executive director of the Molokai Land Trust. “We’ve converted a kiawe, lantana, and buffelgrass-dominated landscape into a native-dominated landscape.”  Seeds of native coastal plants have begun to sprout after decades of dormancy. Volunteers planted seedlings farther inland where the seed bank was depleted by years of cattle grazing. Their efforts are proving successful: carpets of yellow-flowered nehe, ʻilima, and a rare orange ʻōhai now thrive where kiawe and other invasives once grew.

“Their efforts are proving successful: carpets of yellow-flowered nehe, ʻilima, and a rare orange ʻōhai now thrive where kiawe and other invasives once grew.”

Native habitat attracts native critters. These native coastal plants feed and house critically endangered Hawaiian yellow-faced bees. The low-growing vegetation is the perfect place for seabirds to forage. And they do – the variety of seabirds seen at Mokio rivals that of another birding hotspot in the Hawaiian Islands – Kilauea Point on Kauaʻi. Uau Kane (wedge-tailed shearwater), a (both red-footed and brown boobies), and Kaupu (black-footed albatross) are nesting here. Moli – the Laysan albatross – has been sighted along the northern coast of Molokai, landing at Ilio, Anapuka, and Kalaupapa. This led Haase and his crew to wonder if perhaps albatross belonged at Mokio, too.

Orange-flowered ohai (foreground) is one of the endangered plants that have begun to germinate now that invasive species have been removed from the Molokai Land Trust’s Mokio Preserve. Ohai, yellow-flowered ʻilima papa, and other native coastal plants create a low-growing carpet the feeds and houses endangered yellow-faced bees and creates habitat for native seabirds. — BUTCH HAASE / Molokai Land Trust photo

With rising sea levels threatening primary albatross nesting grounds in the Northwest Hawaiian Islands, scientists are trying to increase nesting sites in the main Hawaiian Islands. So Haase, working with the American Bird Conservancy, Maui Nui Seabird Recovery Project, the US Fish and Wildlife Coastal Program, and the Department of Land and Natural Resources, deployed a fourteen albatross decoys complete with pre-recorded albatross calls. Within ten days an albatross had landed, scraping around to investigate a potential nesting site.

This albatross was alone, checking out new territory as young albatross often do, but the amazingly quick response rate is promising. Haase and the rest of the project team hope that within two years albatross could be nesting at Mokio.

That solidifies a deadline for another project at Mokio: the construction of a predator-proof fence to protect ground-nesting seabirds from feral cats, dogs, mongoose, rats, and mice. These predators attack adults and eat their eggs or hatchlings. (Presently, labor-intensive trapping keeps the predator population down). When the fence is complete it will protect 85 acres of potential nesting habitat for Hawaiian seabirds as well as migratory seabirds like kōlea and the kioea, bristle-thighed curlew, a shorebird that cannot fly during its winter molt in Hawaii.

A restored native coastal region in Molokai has been very reassuring to local inhabitants and environmentalists alike. — MISC file photo

The changes at Mokio are dramatic – a cattle pasture transformed into a growing seabird colony now full of native plants. The success so far highlights the resilience of Hawaiian species and their ability to recover when invasive plants and animals are removed. Work at Mokio is ongoing and you can help: Molokai Land Trust welcomes volunteers, both residents of Molokai and visitors from off-island.  If you would like to help in recovery efforts, send an email to volunteersmlt@gmail.com. Follow the progress of the project at molokailandtrust.org and look for them on Facebook.

This article was originally published in the Maui News on May 13th, 2018, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

The native dragonflies and damselflies of Hawaiʻi

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Megalagrion pacificum is an endangered damselfly found on Maui. Evolving over 20 million years of isolation, these native damselflies and dragonflies are threatened by habitat loss and introduced predators like mosquito fish. — U.S. Fish and Wildlife Service / DAN POLHEMUS photo

Twenty million years ago the Hawaiian Island chain was very different from what we see today. Laysan and Gardner Pinnacles were the prominent islands in the archipelago and the main Hawaiian Islands were merely raw lava flowing through the interior of the planet. Around this time a damselfly arrived to the chain, beating the odds in a successful journey across half an ocean.

This single event led to the evolution of some 26 species and sub-species of native damselflies in Hawaiʻi that exist today, according Dr. Dan Polhemus, the Aquatic Ecosystem Conservation Program Manager for the Pacific Islands Fish & Wildlife Office within the U.S. Fish and Wildlife Service. He has studied dragonflies and damselflies throughout the Pacific as well as here on Maui.

Perhaps our most spectacular native insects, damselflies and dragonflies were once widespread throughout the islands. Known as pinao in Hawaiian, these insects now exist only in a tiny portion of their historic range. Introduced predators and habitat loss are to blame. Several species are so rare that they are listed as threatened or endangered. They are often extremely localized; some species are now only found in a single stream.

Pinao adapted to take advantage of the resources available in Hawaiian ecosystems.  They live in a remarkable range of habitats, from mountain streams to marshlands and brackish anchialine pools.

Perhaps because streamflow is often intermittent, some species adapted to survive outside of streams and pools. There are naiads (larval stage of development) that take advantage of water seeps and pockets of rain that collect in the leaves of ʻieʻie vines. One species of damselfly is completely terrestrial – an adaptation existing in only a few other damselfly species in the world.  Their young live in the moist understory of uluhe fern and lack gills found during other damselfly species’ naiad stages.

These hunters evolved eating small insects, both in the water and as they fly through the air. Today, pinao eat a variety of prey, including introduced insects such as mosquitoes. “They are essentially mid-air fighter planes,” says Polhemus. They hunt by folding their legs into a basket to snatch insects from the air. But these aerial predators are prey nowadays.

Lowland marsh and riparian areas have been converted and streams have been diverted. “Intermittent pools have a lot of invasive species,” says Polhemus. Without regular flow to flush out the introduced aquatic species, these pests, such as mosquito fish become established. While the handful of introduced dragonflies have fish avoidance behaviors, the native species, having spent the last 20 million years without predators, are easy prey for non-native fish and other insectivorous invaders. Like native birds in the face of tree-dwelling predators like rats, the larvae are easy picking for voracious mosquito fish. “Where mosquito fish are present, you don’t find native damselflies’” says Polhemus.

Bullfrogs and bulbuls (an invasive bird not present on Maui but found elsewhere in Hawaiʻi) also pose a threat to these ancient colonizers. Bullfrog tadpoles eat dragonfly naiads and bulbuls have been seen snatching the insects from the air.

Ants are another predator. The young naiads climb out of the water to morph into adults on land. Their skin splits open and wings unfold. As they wait for their skeleton to harden and wings to dry they are vulnerable to invasive ants.

There are several species of introduced dragonflies, and most of the dragonflies at low elevation are finddamselflies (distinguished from dragonflies by their ability to fold their wings back at rest) are now found mostly in upper elevations on the Hawaiian Islands, with two species found only on Maui. The largest dragonfly in the United States is found only in Hawaiʻi. Anax strenuus, the Hawaiian giant dragonfly has a wingspan of 6 inches.

You can help protect these unique animals: If you can no longer care for your fish or other aquatic friends, re-home them with someone who can. Never release them into the wild as they can cause ecological damage by pushing out native species, which play an integral role in a healthy Hawaiian ecosystem. Support legislation to maintain streamflow and prevent pollution. To learn more about these fascinating creatures visit: https://dlnr.hawaii.gov/wildlife/files/2013/09/Fact-Sheet-Odonata-damselflies-dragonflies.pdf

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 February 11th, 2018 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles

If you are interested in learning more about the native insects found in Hawai’i, you may enjoy:

Celebrate invasive species prevention: nominate a Maui County landscaper for the Malama i ka Aina award

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2017 Award Ceremony: Allison Wright of the Maui Association of Landscape Professionals, Teya Penniman of the Maui Invasive Species Committee, Joe Imhoff, Henry Imhoff, Sara Tekula, and Jeremiah Savage of the County of Maui. Photo by Bryan Berkowitz/Maui Invasive Species Committee.

 

Nominations are now being accepted to honor invasive species prevention efforts within Maui County.  The Malama i ka Aina Award is presented annually to a landscaper, plant provider (retail and wholesale nurseries and garden shops), or commercial/agricultural property owner/manager to recognize their efforts to keep invasive species out of Maui County.

The award is a cooperative effort of the Maui Association of Landscape Professionals, the Maui Invasive Species Committee, and the County of Maui.

The winner will be announced Saturday, June 16th at the Maui Association of Landscape Professionals’ Maui Garden and Landscape Expo at the Maui Mall.  The winner will receive a plaque, a glass sculpture by artist Jupiter Nielsen, a one-year free membership with the Maui Association of Landscape Professionals and local media recognition.

Applicants are requested to explain how the nominee’s activities or decisions have con

The awardee will receive a glass sculpture by local artist Jupiter Nielsen. A Kamehameha butterfly adorned the 2016 award.

tributed to keeping Maui free from invasive species. Examples include: not selling or using invasive plants; steps taken to learn about invasives; and efforts to reduce use of invasive species by other customers.

Applications are due by Friday, June 1st, 2018 and are available here: 2018 Malama i ka `Aina Award On-line Application

You may submit completed nominations via  email to miscpr@hawaii.edu, fax to 573-6475, or mail to MISC at P.O. Box 983, Makawao, HI 96768. There is no fee to apply. Self-nominations are welcome.  For more information, call 573-MISC (6472), or e-mail miscpr@hawaii.edu.

Past Malama i ka Aina Award recipients were recognized for meaningful steps taken to prevent the spread of invasive species, including incorporating codes-of-conduct in business practices, educating the public and clients about invasive species, and encouraging the use of native species in landscape design. Actions of award recipients are steps in the right direction!

Natural enemies could tame invasive Himalayan ginger

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Though not invasive in India where it is native, Himalayan ginger can completely transform a Hawaiian rainforest as it has in this section at a 4,000-foot elevation above Haiku. Ginger fruits can be spread long distance by birds and rats. — FOREST and KIM STARR photo.

The subtropical rainforests in the foothills of the Himalayan Mountains are amazingly diverse. In sections of India and Nepal, the forests are similar to Hawaiian rainforests in both temperature and rainfall-but the flora and fauna are radically different: this is the land of elephants and red pandas; 600 species of butterflies live here and over 400 species of orchids. But amongst the exotic plants, there is one that might be familiar to residents of Hawai’i-a yellow-flowered ginger that covers vast sections of Hawaiian rainforests.

Himalayan ginger, Hedychium gardnerianum, is native to the Himalayan foothills. There, it evolved over millennia supporting a diversity of species: the sweet nectar is feed for the long-tongued butterflies of the region and the plant lives in harmony with the species that surround it. Yellow flower stalks dot the landscape amongst hundreds of other orchids, gingers, ferns, and trees.

But in Hawai’i, Himalayan ginger dominates the landscape-growing fast and paving its way into the forest in an unrelenting march. “Himalayan ginger displaces critical native vegetation layers, limits canopy tree recruitment, and hogs water resources in their massive rhizomes (roots). As it takes over and forms monotypic stands, it negatively impacts native flora and fauna, including Hawai’i’s unique arthropod complex and the Hawaiian honeycreepers,” says Alison Cohan, director of the Maui Nui Forest Program with The Nature Conservancy (TNC).

Djami Djeddour, weed biocontrol scientist with the Centre for Agriculture and Bioscience International, inspects a lone Himalayan ginger plant in India while searching for insects and fungi that live on the plant where it is native. These insects may be responsible for keeping the plant in check. — DJAMI DJEDDOUR photo.

Introduced as ornamental, Himalayan ginger escaped backyards and began invading rainforests of East Maui in the mid-1950s. With seeds dispersed far and wide by birds and rats, the weedy plant spreads by leaps and bounds into the forest. Today, much of the mid-elevation rainforest of East Maui is a patchwork of native forest and alien ginger. But there is a lot left to protect: many ginger-free areas remain, including most of West Maui. 

Ginger is a formidable foe and removing the plant is no simple task. Roots pave the forest floor like asphalt and every part of the rhizome must be removed. Bagged rhizomes take years to decay and if there is the slightest hole in the bag, hardy shoots emerge. If using herbicide, every portion of the root has to be treated. Plants on steep slopes and cliffs are inaccessible and impossible to remove until the weight of the water-logged roots causes entire sections to collapse in a landslide. Why would ginger be a pest in one place but not another?

Invasive Himalayan ginger taking over the east side of Maui. Ginger fruits can be spread long distance by birds and rats. — FOREST and KIM STARR photo.

The answer to that question is on the minds of resource managers in Hawai’i as well as New Zealand, Australia, and South Africa where the plant is invasive. With funding from organizations like TNC and the Hawai’i Invasive Species Council, research scientists traveled to India and collected insects and fungi that live on Himalayan ginger hoping to discover what keeps the fast-growing herb in balance there. An effective natural enemy could be a game-changer for Hawai’i.

An effective natural enemy wouldn’t eliminate the plant, just bring it into harmony with the surrounding environment, much like it is in India and Nepal. One of the most promising insects is a Cloropid fly that lives only on Himalayan ginger. The larvae live inside the stem stunting the growth and reducing flower production. Ginger natural enemies may be ready for release in New Zealand soon, promising progress for Hawai’i.

“An effective natural enemy wouldn’t eliminate the plant, just bring it into harmony with the surrounding environment, much like it is in India and Nepal.”

“The Nature Conservancy had been doing ginger work in Waikamoi for over 30 years, systematically conducting ginger control—containing the core population at the western edge of Waikamoi and eradicating outliers in native forest,” explains Cohan. Crews with Haleakalā National Park work on the flowering pest in Kīpahulu Valley but the plant is widespread and thrives unchecked in wet places throughout the state. 

There are ways you can help. Consider what you call the plant: though known for years as kāhili ginger, a pest destroying the rainforest does not deserve a moniker reminiscent of Hawaiian royalty much less one that might suggest that it belongs here. Perhaps call it toilet-brush ginger, as suggested by Pat Bily of TNC after years of removing it. Do not plant Himalayan ginger in your yard and remove it from your property before it spreads. Finally, participate in The Nature Conservancy’s quarterly volunteer trips removing ginger from Waikamoi Preserve. Contact hike_waikamoi@tnc.org if interested.  

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 April 3rd, 2018, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

A possible solution for the weedy tibouchina

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The upper elevations of the West Maui mountains are home to unique plants and animals found only here. Among them, species of lobelia and dwarf ʻōhiʻa. Tibouchina is one of the persistent threats to the survival of these rare species. Photo by Lissa Strohecker.

Tucked away in the rain and fog of the West Maui mountains are uniquely Hawaiian treasures: high-elevation bogs carpeted by rare and restricted plants. The last few hāhā (Cyanea magnacalyx) existing in the wild anywhere in the world are found there. Dwarf ʻōhiʻa, two unique silverswords, and many other plants are restricted to the high summit bogs and have adapted to the wet substrate.

Conservation crews monitor these bogs closely–they are in a section of West Maui that is fenced and protected from pigs, goats, and deer. Nonetheless pinhead-sized seeds of invasive cane tibouchina (Tibouchina herbacea) blow into the bog from the lower elevations and threaten the fragile ecosystems.

If crews did not remove tibouchina, it would take over the bog, crowding out the Cyanea and other endangered plants. It’s only in these ecologically sensitive bogs that crews remove tibouchina–there is simply too much of it on the surrounding slopes. As a result, it’s a continuous battle.

“Tibouchina is scattered throughout the 50,000 acre watershed of the West Maui. It’s found from sea level to the summit of Puʻu Kukui, but thrives in the wet windward slopes between 2,000-4,000 feet,” says Chris Brosius, manager of the West Maui Mountain Watershed Partnership. His crew helps to protect the bogs along with the rest of the watershed.

“West Maui is the steepest land area in the state, more dissected by cliffs than any other watershed in the Hawaiian Islands,” says Brosius. Even if they had the capacity, “We couldn’t possibly control this species everywhere it grows.”

Tibouchina thrives where there is soil disturbance–whether from pigs or the landslides that helped shape the West Maui’s. Tibouchina is often the first plant to arrive after a landslide.

Tibouchina belongs to the melastome family, a group of plants that are notoriously invasive in Hawaiʻi–miconia and clidemia are both melastomes. An ugly second-cousin to miconia, tibouchina is often leggy and scruffy looking. The leaves are two inches long, fuzzy, and lack the purple underside that characterizes miconia; the purple flower is pretty, but small–unlike the closely related glory flower.

A member of the melestome family, tibouchina is a notorious invader thatʻs past the stage of containment. Photo by Forest and Kim Starr.

Biologists first noticed tibouchina in 1977 on Big Island and in 1982 near Waiheʻe Ridge on West Maui. Within a few years it had spread throughout Maui, Lānaʻi, and Hawaiʻi Island. By 2005 it was found on Oʻahu, likely introduced on dirty hiking boots. It has shown up on Molokaʻi as well. As a trailside weed, it can be problematic–hikers passing through a patch of tibouchina end up coughing as tiny hairs are knocked off and the plant can be a skin irritant.

Tibouchina is native to Brazil. It can be difficult to find there–occasionally appearing in wet areas and meadows. It only reaches three feet in height and dies back every year. But here in Hawaiʻi, tibouchina can be 9-12 feet high. When last year’s growth dies back, the plant re-sprouts from the roots, creating bamboo-like thickets and taking over habitat for native species.

Why would the plant behave so differently here? One explanation is the lack of predation. Tibouchina evolved in Brazil alongside insects that munch its leaves, seeds, and roots. These insects are not present in Hawaiʻi, so tibouchina grows and spreads unchecked. One of tibouchina’s natural predators is a small beetle–both the larvae and the adults devour tibouchina leaves.

The beetle, called Syphrae uberabensis, can only survive by eating tibouchina and select other melastomes, none of which are native to Hawaiʻi. After 20 years of work collecting and evaluating the beetle’s impacts on other species in quarantine, US Forest Service scientists are confident that the beetle poses no negative threat and are preparing to release it into the wild.

An insect that relies on tibouchina for survival is in the final stages of evaluation for release in Hawaii. The syphrae beetle could make tibouchina less invasive. Photo by Forest and Kim Starr

The syphrae beetle could be what takes tibouchina down a notch–reducing the threat it poses to the remaining habitat of Hawaiʻi’s rarest native plants and animals. “If we don’t intervene, this species will continue to encroach on high-value native areas, erode biodiversity and spread elsewhere in the state,” says Brosius.

Tibouchina is just one example of a widespread pest with dramatic impacts. You can help by cleaning your hiking and hunting gear to prevent spreading hitchhiking pests.

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 January 14th, 2018 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles

If you are interested in the use of biological control in Hawaiʻi, check out these posts:

 

African Tulip Tree

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African tulip trees are a common sight along the Hana Hwy. Photo by Forest and Kim Starr

An African tulip tree in bloom is a remarkable burst of color. Consequently, the tree has earned many monikers: flame of the forest, fountain tree, and fireball. Scientists know it as Spathodea campanulata and this East African Native has been in Hawaiʻi for a long time. Renowned physician and botanist William Hillebrand first planted African tulip trees in Hawaiʻi in the late 1800s. Around 1915 Joseph Rock, another prominent figure in Hawaiian botany, introduced S. campanulata seeds collected in Java. In the late 1920s and 30s foresters planted and dropped African tulip seeds by air throughout many parts of the state. On Maui nearly 30,000 trees were planted. But as the “flame of the forest” spread and awareness of invasive species increased, people began to be concerned about the trees spreading.

We now know that African tulip trees are invasive and damaging to Hawaiian ecosystems. They grow extremely fast; in Puerto Rico they can increase 2” in diameter per year, shooting up from the forest floor and outcompeting other plants for sunlight. They can be a notorious pasture pest, springing up when land is cleared and creating a field of tulip trees with little else. Prolific seeders, their papery oatmeal-like seeds blow in the wind for miles. But perhaps what makes these trees most invasive is their shade-tolerant seedlings.

Shade tolerance means a seedling can sprout in an intact, shaded forest, then invade and dominate the landscape. This contrasts with many other invasive species that depend on disturbances and light gaps to gain a foothold. African tulip invades either way.

Given that African tulip seedlings can germinate and grow with little sunlight, they can creep into undisturbed forests and take over, growing faster than surrounding plants and expanding their domain. That is exactly what has happened along the windward slopes of East Maui. Beauty is in the eye of the beholder, and to those who know, the pretty, bright orange flowers ascending the hills above Hāna represent a garish plague. Potentially replacing ʻōhiʻa, ʻōlapa, maile and other native plants. The higher they go, the more likely they are to affect native forests.

The silver (or orange) lining to the presence of African tulip trees in our forests is currently limited in their ability to grow at high elevation. The flame of the forest peters out at around 3200’ elevation, near the boundary of the native dominated forest. The low-elevation forests where African tulip tree is found are already dominated by non-native plants, so the orange invader just dukes it out with other weedy pests.

Prolific seeders, these introduced species have invaded much of the low-elevation forests of Hawaii. However, they seem unable to grow at elevations above 3200′ in Hawaii.  Photo by Forest and Kim Starr.

Near the border of the native forest though African tulip’s impacts are magnified. When possible, it should be removed. That is what Lance DeSilva with the department of Land and Natural Resources Division of Forestry and Wildlife is doing, both on Maui and Molokaʻi. In East Maui he’s decided to push back the upper elevation presence of African tulip tree by controlling the far-reaching plants in the Koʻolau Forest Reserve, particularly in and around Waihou Valley. “It’s my professional and personal goal to shrink the African tulip tree population of Koʻolau Forest Reserve,” says DeSilva. To date he and his team have removed over 650 trees. On Molokaʻi he’s taken out 48 trees along the north shore of Molokaʻi.

You can help. Don’t plant these trees, and if you already have them, consider removal. They are a particular hazard near homes and roads due to their tendency to drop limbs. For advice on removing African tulip tree, review the College of Tropical Agriculture and Human Resources’ handout on the Incision Point Application Technique: https://www.ctahr.hawaii.edu/oc/freepubs/pdf/WC-11.pdf.

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 May 14th, 2017 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles

Africanized honey bees could threaten Hawaiian honeybee populations

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Africanized honeybees, like the one shown here from Florida, look nearly identical to a common honeybee — the main difference is in their behavior. Africanized honeybees are not known to be in Hawaii and residents can help prevent them from becoming established by reporting unusually aggressive bees to the Hawaii Department of Agriculture’s Apiary Program. — Florida Department of Agriculture and Consumer Services photo

In 2011, alert harbor workers in Honolulu noticed bees inside a container of medical supplies shipped from Long Beach California. They closed the container and notified the Hawaiʻi Department of Agriculture (HDOA). The container was fumigated and HDOA sent the bees in for genetic testing: they were Africanized honeybees.

Honeybees are fairly widespread in Hawaiʻi, both in managed and feral hives. But we don’t have the Africanized honey bees that are present in much of the southern United States and Central America.

Africanized honeybees are nearly identical to their six-legged relatives kept for honey production: they look the same and they produce honey, but they are much more aggressive in defending their hives. Even something as insignificant as a barking dog can trigger bees to attack and ten times as many bees will descend. “It’s of particular concern when the person can’t get away from the attack,” says Noelani Waters, an entomologist with the Hawaiʻi Department of Agriculture’s apiary program. For the elderly, young children, or those with bee allergies, an attack can be fatal. “They have come already once,” says Waters “it’s very possible and extremely likely they will make it here again.”

With that in mind, HDOA has set up swarm traps around the harbors and airports. Monitoring around the airport is through the Māmalu Poepoe project, an interagency cooperative group that works to stop invasive species from reaching Hawaiʻi through airports. Every 6 weeks or so, crews walk around Kahului airport peering in gigantic, brown papery pots mounted about head height and baited with a pheromone to attract bees. These are swarm traps, designed to be the perfect landing place for swarming bees in search of a place to start a new hive. The goal is to intercept any Africanized bees before they become established.

Noelani Waters (center) of the Hawaii Department of Agriculture shows Maui Invasive Species Committee early-detection specialists Forest and Kim Starr a swarm trap at the Kahului Airport. These containers are designed to look like the perfect home for a swarm of bees looking for a place to build a hive. These traps are set up at harbors and airports throughout the state in hopes of intercepting Africanized honeybees arriving in cargo. — FOREST and KIM STARR photo

African honeybees were first introduced to Brazil in 1957 with the goal of breeding honeybees better able to produce honey despite the heat and humidity. Unfortunately, they escaped quarantine before the less desirable traits–like their aggressive behavior–could be bred out of them.

The introduced drones hybridized with surrounding bees and continued to spread, taking over existing hives. Africanized honeybees spread north through Central America and into the Southern US. They first showed up in 1985 in California, traveling in contaminated cargo. By 1990, they had expanded from Mexico into Texas and are now spread from Florida to Southern California. Cooler temperatures likely limit their spread farther north, but the tropical climate of the Hawaiʻian Islands is hospitable to these bees.

Hawaiʻi has native bees – the solitary yellow-faced bees—but honeybees are introduced. Beekeepers brought these insects to the state in 1857. Initially, they were introduced to increase kiawe pollination, used at the time as a high-protein cattle feed. Today, honeybees in Hawaiʻi are some of the world’s highest honey producers. The lack of Africanized bees and overall health of Hawaiʻi-raised honeybees has led to a $10 million per year queen bee export industry. According to Waters, hives queened with Hawaiʻi-raised bees are key to the pollination of almond crops in California every spring. Hawaiʻi supplies 25% of the queen bees for the mainland U.S. and 75% of the queen bees imported to Canada. Hawaiʻi’s agricultural industry would suffer if Africanized honeybees reached our islands. These aggressive hybrids also threaten human health and safety. You can help. Report particularly aggressive hives, feral or managed, to Waters and her colleagues at the Hawaiʻi Department of Agriculture’s Apiary program at (808) 974-4138. Learn more about the program online at https://hdoa.hawaii.gov/pi/ppc/apiary-program-hawaii-beekeepers-registry/

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 December 10th, 2017, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

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Contact Us

Maui Invasive Species Committee (MISC)
Office: (808) 573-6472
Press and Media Inquiries: (808) 344-2756
Mailing Address:
PO Box 983, Makawao, HI 96768

Acting Manager / Public Relations: Lissa Strohecker
E-mail: miscpr@hawaii.edu

Special Projects: Teya Penniman
E-mail: miscmgr@hawaii.edu

Statewide Pest Hotline: 808-643-PEST
Report a Pest Online