Kia’i Moku Column — Page 6 — Maui Invasive Species Committee (MISC)

Invasive jellyfish removed from Kaunakakai harbor

Posted on November 23, 2020 by Lissa Strohecker

Crews from the Molokai/Maui Invasive Species Committee and the Division of Aquatic Resources remove invasive upside-down jellyfish from the swimming area at Kaunakakai Harbor. They visit several times a year to keep the community swimming area free of these stinging pests. — Molokai/Maui Invasive Species Committee photo.

Back in 2009, a father and his two kids, still wet from the beach, walked into the office of the Molokai/Maui Invasive Species Committee. The kids were covered in welts. Dad carried a bucket containing a flat brownish thing. “This is stinging my kids,” he said.

He had captured an upside-down jellyfish, a relatively new creature in Hawaiʻi. The species anchors itself to the ocean floor upside-down, tentacles waving in the shallow water. “They look like big pancakes,” says Lori Buchanan, manager of the Molokai/Maui Invasive Species Committee (MoMISC).

For the jellyfish, this wrong-side-up strategy works: they use their bell as a foot to anchor themselves in place then, like coral, they partner with symbiotic algae that feed the jelly through photosynthesis. But these gelatinous blobs can pose problems for people in their midst: like many of their upright relatives, these jellyfish sting shooting harpoon-like nematocysts into the water when touched. When a single upside-down jelly stings, it can trigger the same reaction in his neighbors, leaving a stinging nematocyst floating in the water—a nightmare for snorkelers and swimmers.

The jellyfish delivered to Buchanan’s MoMISC office came from Kaunakakai Harbor–specifically, the roped-off swimming area that teemed with kids that summer. This was an urgent problem and Buchanan and her crew sprang into action to solve it.

Upside-down jellyfish arrived in Hawaiʻi hitchhiking on the bottoms of boats or in ballast water. They rest on the ocean floor, favoring shallow calm areas like lagoons and fishponds. Without predators, they can completely cover an area. — Molokai/Maui Invasive Species Committee photo.

With nets and buckets, the crew went to work, scooping jellies from the wharf. That first year, MoMISC crews removed 200 stinging jellies. They’ve kept at it, sometimes partnering with the crews from the Department of Natural Resources’ Division of Aquatic Resources. Visiting two to four times per year keeps the population down. Since their initial trip, they’ve removed 400 more of the squishy stingers.

These invasive jellyfish probably hitched a ride to Kaunakakai on the bottom of a boat – but that was not the first time they were seen in Hawaiʻi. First reported from Pearl Harbor in 1914, then in Kāneʻohe Bay, they likely arrived on the hull of a visiting ship, or as larvae in ballast water. They’ve invaded several places throughout the state, favoring shallow lagoons and fishponds where the water is calm.

Scientists believe the various populations resulted from at least two different introductions from far-flung places. Looking at the genetics of the different colonies, they traced one to Papua New Guinea and another to the Atlantic.

These spineless invaders are sometimes called mangrove jellyfish, for good reason. The two species are often found together. Here in Hawaiʻi, mangrove trees are invasive, and their presence can influence the population of upside-down jellyfish. As mangrove leaves break down in the water, they release chemicals that trigger larval jellyfish to settle down. The alien invertebrates then flip themselves over and rest in the shallow, clear water around mangroves. During MoMISC’s drive to remove the upside-down jellyfish, the crew noticed mangroves lining the wharf and removed them as well.

Without natural predators, these aquatic aliens can quickly cover an area. Buchanan says a fishpond on Molokai’s east end is so infested you can’t see its bottom.

Upside-down jellyfish have migrated from Pearl Harbor to Coconut Island in Hilo. So while Buchanan’s team won’t be able to remove them completely, it’s worth the effort to keep them suppressed in swimming areas. “The wharf is the most popular place on Molokai,” says Buchanan. “Especially in the summer, it’s like the mall.”

Aquatic invaders are no fun. You can help prevent them from spreading by keeping your boat free of hitchhikers. If you are interested in the role of hull-fouling and ballast water contamination in the spread of invasive species, check out this web page: http://dlnr.hawaii.gov/ais/ballastwaterbiofouling/ballastwaterdetails/

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

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ʻŌhiʻa’s genetic diversity may contribute to disease resistance

Posted on November 23, 2020 by Lissa Strohecker

The natural genetic variation in ʻōhiʻa may translate to some resistance to Rapid ʻŌhiʻa Death. To both preserve the genetic diversity present in ʻōhiʻa and test for disease resistance, there are seed banks established throughout Hawaiʻi. — Masako Cordray photo

ʻŌhiʻa is both a pioneer – the first to grow on new lava– and a protector—hosting and sustaining birds, insects, and plants throughout Hawaiʻi. ʻŌhiʻa is at home in nearly every terrestrial ecosystem in the islands, from the wettest rainforests to the leeward slopes of dryland forests. Its flowers range from cool yellow to fiery red. Leaves can be small, curled and fuzzy, and snuggled together along the stem, or stretched, shiny and drooping. The tree may crawl, bonsai-like on mountain tops, or assume a stately, spreading pose above the rainforest. The plant’s scientific name, Metrosideros polymorpha, only begins to reflect the “many morphs” of ʻōhiʻa. ʻŌhiʻa exhibits so much variation that taxonomists have classified the tree into different species and varieties, seven of which occur on Maui.

While ʻōhiʻa is amazingly adaptable, the reliance of so much native biota on its existence exposes a vulnerability. Without ʻōhiʻa, our forests – dryland to mesic to the rainforest – and the species within them are in peril. Rapid ʻŌhiʻa Death, the fungal disease that has killed ʻōhiʻa across 135,000 acres of Hawaiʻi Island, and counting, makes this abundantly clear. The discovery of this pathogen on Kauaʻi in 2018 further underscores the risk, even though it is not yet known from the other islands.

“The goal is to preserve the genetic diversity of ʻōhiʻa naturally present in the landscape,” says Dr. Marian Chau.

Ripe ʻōhiʻa seeds being grown on the Hawaiian Islands for the preservation of the native species. —

One source of hope is that ʻōhiʻa’s high degree of genetic diversity could contain the key to disease resistance. Across the state, foresters and conservation groups are partnering on a project to collect and store seeds in ʻōhiʻa seed banks. “The goal is to preserve the genetic diversity of ʻōhiʻa naturally present in the landscape,” says Dr. Marian Chau, seed lab manager at Lyon Arboretum on Oʻahu. “The seeds can be used for current research on potential genetic resistance to Rapid ʻŌhiʻa Death, and for future restoration.” ʻŌhiʻa produces plentiful seed that can be stored for up to 18 years. To preserve and represent this variation, the seed collection campaign has a lofty goal of obtaining seeds from 10,000 different trees of fourteen different species.

Each island is divided into seed zones and collectors record the zone where they harvest seeds. If there is no representation from a particular zone, Chau and her colleagues reach out to those working in the area. The Laukahi Hawaiʻi Plant Conservation Network, a voluntary alliance focused on protecting Hawaiʻi’s rare plant species, created the seed zones and manages the data.

Throughout Hawaiʻi, partnerships have been made to collect wild-grown ohia seeds. There are currently more than four million seeds in the collection — Laukahi Network photo

With support from the Hawaiʻi Tourism Authority, Chau has traveled across the state offering free training on how to properly collect ʻōhiʻa seeds. Her workshops cover identifying the variety; determining if seeds are ripe; cleaning and packaging ʻōhiʻa for storage; and recording and submitting collection data. The trainings are empowering community participants to help stop the devastation of Rapid ʻŌhiʻa Death. The workshops are open to the public, but only naturally-occurring ʻōhiʻa are candidates for seed banking, not landscape-planted trees. To collect seeds from ʻōhiʻa in the wild, landowner permission and necessary permits for state or federal land are required.

To guard against inadvertent destruction (e.g., from a tropical storm), the seedbanks are scattered throughout the state, with redundant banks in different locations. Hawaiʻi Island seeds are stored on that island due to concerns about the accidental spread of the disease.

You can find more information about seed banking efforts online at http://laukahi.org/ohia/ including ʻōhiʻa identification information, seed collection guidelines, data collection, and needs. Learn more about Lyon Arboretum’s Seed Conservation Laboratory at manoa.hawaii.edu/lyon/research/hrpp/. Stay up to date on Rapid ʻŌhiʻa Death at rapdiohiadeath.org and through the Rapid ʻŌhiʻa Death Facebook Page.

This article was originally published in the Maui News on June 9th, 2019 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Māmalu Poepoe Project traps and monitors invasive pests

Posted on September 15, 2020 by Lissa Strohecker

Crews from island-based invasive species committees from across the state receive training on signs of a coconut rhinoceros beetle. The training is done as part of the Mamalu Poepoe project, an interagency working group designed to increase the monitoring capacity at airports statewide. — LEYLA KAUFMAN photo

Since Polynesian times, people have unwittingly carried plants and animals with them as they traveled to Hawaiʻi. Ants and skinks were among the first of these hitchhikers inadvertently brought to the Islands. The natural barriers of isolation that prevented so many plants and animals from reaching the Islands have been wiped out.

Every day, between 25,000-30,000 people fly to Hawaiʻi from throughout the world: In 2016, 655,000 tons of air cargo and mail arrived through the airports across the state. The Hawaiʻi Department of Agriculture inspects much of this cargo for hitchhiking pests. But pests could slip through: species that stowaway in cargo holds, or between airline shipping containers—species inadvertently picked up at one destination and carried to another, from international airports to interisland airports.

The Māmalu Poepoe project is designed to address that puka. Māmalu means protected, Poepoe is an acronym for point of entry, point of exit – the name connotates a “lei of protection.” According to Leyla Kaufman, coordinator of the Māmalu Poepoe project, the main goal of the project is to increase monitoring capacity at the airports. “In most instances, the agencies involved have some level of monitoring going at airports, [Māmalu Poepoe] fills in any gaps.”

The seed for the project was planted in 2013: with the Hawaiʻi Department of Health so low on funding they had no capacity to trap and monitor mosquitos around the airports, then-deputy Gary Gill reached out to interagency Hawaiʻi Invasive Species Council. They started planning for the Māmalu Poepoe project.

This coordinated working group leverages the expertise and manpower of multiple state agencies: primarily the Departments of Health, Transportation, and Agriculture under the umbrella of the Department of Land and Natural Resources’ Hawaiʻi Invasive Species Council. The University of Hawaiʻi provides a flexible umbrella for funding between multiple agencies.

Work occurs in the restricted access areas of 6 airports statewide: Kauai, Oahu, Molokai, Maui, Hilo, and Kona. Traps and surveys are designed to target mosquitos, ants, coconut rhinoceros beetle, and honeybees. These insects are selected because they are notorious hitchhikers that have an impact on agriculture and human health. By monitoring, the Māmalu Poepoe project can better address both the interisland spread of pests as well as the introduction of species to the state. “Hawaiʻi has 6 species of mosquitos but there are hundreds out there,” says Kauffman. One of the species found on Big Island but not the rest of the state is Aedes aegypti, the mosquito that is the optimal carrier for dengue and zika, it can also transmit chikungunya and yellow fever.”

Agency specialists from the state agencies design the monitoring and survey methods, but given scarce staffing and travel funds, they rely on a crew from the island-based Invasive Species Committees to do the groundwork of checking traps and surveying for ants. Crew go through species-specific trainings (as well as background checks for security authorization) —then visit the airport every 4-6 weeks to check the swarm traps for honeybees, the lure traps for coconut rhinoceros beetles and mosquitos, or survey for ants.

“Rather than starting from scratch….It (Māmalu Poepoe Project) has allowed us to tap into much more expertise than we would have had otherwise, and is helping support a much larger network of folks working on a piece of the monitoring puzzle.”

Māmalu Poepoe project is flexible enough to fill gaps in the research: “Things have changed quite a bit since the Department of Health was monitoring for mosquitos at airports,” says Kauffman. She started a research project evaluating mosquitos to enhance trapping efforts of vector control.

In the three years from the proposed idea to actual implementation, the landscape around invasive species changed: Coconut Rhinoceros Beetle arrived in the State and the dengue outbreak triggered the legislature to restore funding for vector control. Josh Atwood, Program Supervisor of the Hawaiʻi Invasive Species Council feels it is a boon for the project: “Rather than starting from scratch….It has allowed us to tap into much more expertise than we would have had otherwise, and is helping support a much larger network of folks working on a piece of the monitoring puzzle.” Learn more about the project online: https://dlnr.hawaii.gov/hisc/mp/

This article was originally published in the Maui News on November 12th, 2017, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Yellow-faced bees defenseless and vulnerable to predatory ants

Posted on August 11, 2020 by Lissa Strohecker

Female bees lack the yellow faces that lead to the common name of the yellow-faced bees. Once common, many of these bees are now on the endangered species list. — JASON GRAHAM photo.

Somewhere between 400,000 and 700,000 thousand years ago–about the time Haleakalā was forming–a tiny bee arrived in the Hawaiian Islands.

This bee was about the size of a grain of rice and prepared for a life of self-sufficiency. Though we think of bees as living together, working together, and providing honey, approximately 75% of the bee species in the world lead a solitary life. Simply pollinating flowers – an essential ecosystem service— they are often overlooked by people.

Little is known about the first bee to reach Hawaiʻi, but in a remarkably short amount of time, her descendants evolved into 63 unique species found only in Hawaiʻi. They were successful, living from the coastline to the mountain top, pollinating everything from naupaka to silverswords. They were so common in 1913 that entomologist R.C.L. Perkins called them “almost the most ubiquitous of any Hawaiian insects.”

The last hundred years have brought dramatic changes to Hawaiʻi and seven species of Hawaiian yellow-faced bees have since landed on the federal endangered species list. According to Dr. Jason Graham, a University of Hawaiʻi at Mānoa researcher, the other Hawaiian bees may not fare much better. “There is the potential that others are endangered or extinct,” he says, “there hasn’t been much work on them.” Habitat loss and invasive species are the unique bees’ primary threats.

With few exceptions, Hawaiian bees rely on native plants for food. They are not found in areas dominated by non-native plants. The decline in food sources has led to a decline in population. Introduced bees and wasps compete with the native bees for food and nesting sites. Exotic ants also take a toll.

An endangered yellow-faced bee visits a native beach naupaka. Endemic yellow-faced bees rely mostly on native plants for food and nesting sites. — JASON GRAHAM photo.

Yellow-faced bees don’t sting, which often leads to the death of a bee. “If a honeybee worker dies, the hive continues,” explains Graham. But a solitary bee isn’t expendable – she wonʻt pass along her genetic material. “She’s the single mom of the insect world,” says Graham.

It’s up to her to find a nest, typically a hollow stem or hole in a rock or coral. She builds a little apartment for each egg, stocking the cupboards with pollen, food for when the larvae emerge. She seals the opening with a waterproof coating to protect her young from the elements and off she goes – her caregiving role complete.

But the neighborhood has changed in 200 years; now her unattended young are vulnerable to multitudes of invasive ants that easily pierce the cellophane-like barrier to the nest. Years of evolution in isolation have left the yellow-faced bees defenseless and vulnerable to non-native predatory ants that crawl inside the nest and devour the young.

“Years of evolution in isolation have left the yellow-faced bees defenseless and vulnerable to non-native predatory ants that crawl inside the nest and devour the young.”

Some Hawaiian bees, such as the highly endangered Hylaeus anthracinus, are limited to small populations along the coastline. “Climate change and rising sea levels are a definite threat to the future survival of this species,” says Graham who is investigating artificial nesting sites for the bees. Since yellow-faced bees rely on existing holes for nests, Graham drills into blocks of wood and line them with plastic tubing so he can pull the nest out and monitor success. He can use an insect barrier to keep ants out.

Understanding Hawaiian bee biology is essential to protecting them. You can help:

Use native plants in your landscaping.
Bring your own kindling: For some of the most endangered coastal species, nest sites can be destroyed when people collect wood for bonfires. What looks like a dried naupaka twig may actually contain a tiny bee’s nest.
Entomologists are in the beginning stages of research but they will eventually need assistance – if you want to help monitor nests and find native bees, follow the Hawaiian Yellow-Faced Bees page on Facebook and check the discoverbees.com website.

This article was originally published in the Maui News on July 9th, 2017, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Coqui frogs negatively affect the environment in more ways than one

Posted on June 18, 2020 by MISC

Coqui have the perfect environment in Hawaiʻi, one that lacks the predators – lizards, tarantulas, and snakes- found in their native Puerto Rico. They reach densities two to three times greater in Hawaiʻi than in Puerto Rico, the densest population of land-living amphibian known anywhere. — Maui Invasive Species Committee photo.

In the dark, Darrel Aquino turns off the pump engine – the silence is a stark contrast to the noise of the gasoline motor, and before that, the piercing calls of the coqui frogs that met Aquino and his crew from the Maui Invasive Species Committee when they arrived hours earlier. They work together to pack up, rolling up fire hose by the light of headlamps before heading back to the baseyard. They’ll be back out tomorrow, and the night after, but in a different area of Haʻikū, as they work to stop the spread of the coqui frog.

From dusk to dawn males call for mates, “Co-qui, co-qui.” The first note, “Co,” lets their competition (other male frogs) know they are there, and the “qui” is for the girls. As loud as a lawnmower or leaf blower, the calls drown out the sounds of a night in Hawaiʻi: crickets, the night breeze rustling leaves, waves breaking along the coast.

But while the ear-splitting call of this tiny tree frog is what they are famous for, problems with the coqui frog goes beyond noise. Like us, these invasive frogs from Puerto Rico also find our island habitat and climate to be paradise. Coqui in Hawaiʻi reach population densities greater than any terrestrial amphibian species elsewhere in the world. At over 20,000 frogs per acre in an environment that evolved without frogs, there is bound to be an impact.

“Coqui in Hawaiʻi reach population densities greater than any terrestrial amphibian species elsewhere in the world. At over 20,000 frogs per acre in an environment that evolved without frogs, there is bound to be an impact.”

Dr. Karen Beard, a professor at Utah State University, and her students have studied coqui frogs in the Islands for more than a decade. The interactions between invasive species from different parts of the world coming together in a new environment can be hard to predict, but her research is finding that the presence of coqui in Hawaiʻi tends to benefit other introduced species – from invasive plants to non-native birds to mongoose.

Coqui frogs alter the way nutrients cycle in the ecosystem. The frogs feed on insects, mainly ants, roly-polies, cockroaches, and earthworms, but not mosquitos. What goes in must come out and hundreds of thousands of invasive frogs contribute additional nitrogen and phosphorus to the soil. Though these additions help plants grow, the increase really only benefits introduced plants. The flora native to the Hawaiian Islands is adapted for nutrient-poor volcanic soils, so by increasing soil nutrients, the coqui frogs modify conditions to favor invasive plants such as strawberry guava (native to Brazil).

Coqui frogs also bolster populations of non-native birds. Beard found that populations of some introduced songbirds, including common myna, Chinese hwamei, and red-billed leiothrix (all from Asia), are higher where coqui frogs are present. This is likely due to changes in the insect community when coqui are present (more excrement and frog bodies means more flies) as well as birds consuming the eggs in addition to juvenile and adult coqui.

Mongoose (from India) may also benefit from coqui. Beard’s graduate student Shane Hill looked at rat and mongoose densities where coqui are present compared to where they are absent and found greater mongoose abundance with coqui present. Mongoose are the main scavengers of coqui frogs, which may provide a novel food source. Hill also concluded that increased numbers of non-native birds or coqui-induced habitat changes could favor mongoose.

An invasive mongoose thriving off the abundance of the coqui frog population while increasing the likelihood of predation to other native Hawaiian species. — photo courtesy of Karen Beard

Hill’s study also showed fewer rats where coqui are present, more so for Pacific rats, which den underground as opposed to the more arboreal black rats. Hill and Beard suggest lower rat abundance could result from competition with coqui for insects or increased predation by mongoose. While the relationships are complex, one thing is clear: more mongoose is not good for ground-nesting birds, such as the ʻuaʻu kani (wedge-tailed shearwater) or endangered ʻuaʻu (Hawaiian petrel), and coqui could indirectly contribute to a decline in these birds.

Humans may adapt to the noise of coqui but the environment may be forever changed by their presence; interactions among these invasive frogs and other introduced pests tend to compound the impacts. It’s critical to do what is possible to keep these invasive pests out of the native-dominated areas of Hawaiʻi and sensitive bird habitat.

You can help stop the spread of coqui on Maui. If you have coqui, volunteer in your neighborhood to reduce coqui and remove frog-friendly habitat. If you don’t have coqui in your area, stay alert to any nighttime “Co-qui” calls and report it to MISC at 573-6472.

This article was originally published in the Maui News on February 10th, 2019 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Measuring the impacts of invasive plants in Hawai’i’s watersheds

Posted on June 5, 2020 by MISC

University of Hawai’i professor and researcher Tom Giambelluca is looking to better understand how invasive plants, like strawberry guava on the right, disrupt the water collection function of a native rain forest like that on the left.

In Hawaiʻi, the supply of fresh plentiful water depends on the forest capturing moisture from fog drip and rain, and then move it to streams and aquifers. Scientists and resource managers know that invasive plants disrupt the capacity of a native ecosystem to collect water. In Hawaiʻi, invasive species are the greatest threat to the function of native ecosystems.

But there are many unanswered questions about how and to what degree invasive plants affect the water capture in Hawaiʻi. Water capture, depends on both rainfall and cloud or fog drip, water then moves through the forest and soil to streams and underground reservoirs (aquifers). Some water is lost through evaporation and transpiration – the movement of water from roots through the leaves and into the atmosphere.

Like straws, plants pull water out of the ground and release it into the air. Differences in both the physical structure and growth characteristics contribute to different rates of transpiration between native and invasive species. Tom Giambelluca is looking closely at those differences. Giambelluca is the director of the Water Resources Research Center and a Professor in the Department of Geography and Environment at the University of Hawaiʻi at Mānoa. He has spent much of his career looking at the impacts of invasive species on water resources in Hawaiʻi. His latest research attempts to tease out and quantify how invasive species increase the loss of water back into the atmosphere.

“One of the reasons invasive plants take over might be that they grow faster,” he says. “Faster growing plants tend to use more water” and over the long run, as invasive plants take over the native dominated forest, these differences in transpiration rates could have significant impacts on the cycle of water through the environment and the availability of water for human use.

To quantify these impacts, Giambelluca has relied on an experimental model of setting up monitoring equipment in paired sites where forest dominated by native species is growing immediately adjacent to stands of invasive plants. This site selection eliminates differences that may be caused by soil types and weather patterns in geographically separate locations. Weather can vary dramatically within small distance in Hawaiʻi. He then looks at the differences in transpiration by setting up tall towers filled with monitoring equipment and using measurements of water flow moving up the stems of sample trees.

But suitable study sites are hard to find – and funding additionally limits the number of sites he can potentially set up. With only a limited number of sites, he can’t accurately predict the impacts of invasive species may have on transpiration rates across the landscape.

So, Giambelluca is developing an experimental model wherein he can evaluate sites based on data that can be collected in a single day, therefore enabling his team to gain a better understanding of how individual differences in plant transpiration rates can impact water capture throughout Hawaiʻi. And he’s focusing primarily on leaves.

“Leaves are where the action is,” explains Giambelluca. “It’s where the plants control the uptake of carbon dioxide and release of water vapor.”

He takes a handful of measurements including the leaf area index (the surface area of all leaves over a given area), and leaf gas exchange rates of different plant species. The more leaves in an area, the higher the transpiration rates. Invasive – dominated forest tends to have a higher leaf area index (i.e,. more leaves). Plant species transpire at different rates. After he has enough data to be statistically significant, he can then combine that with distribution maps of plant species across Hawaiʻi, and better assess the impacts invasive species have on the amount of water lost through transpiration.

While still in the proposal stage with results a few years in the future, the potential outcomes from this research could help inform the decisions resource managers and funders face in setting priorities both for which species should be controlled as well as which areas are more sensitive to the impacts of invasion. In the meantime, enjoy a fresh glass of water brought to you by a native forest nearby.

For more information on Giambelluca’s research, check out his lab page at https://sites.google.com/a/hawaii.edu/ecohydrology_lab/

Originally published in the Maui News on November 9th, 2019.

Tiny golden butterfly could help halt miconia invasion

Posted on April 28, 2020 by Lissa Strohecker

Caterpillars of the golden miconia butterfly can only survive on miconia and related plants. The caterpillars get together in clumps and devour the leaves. In doing so, they may reduce the damage miconia can cause in the rainforest. — PABLO ALLEN photo

In the hills above Hāna, Nāhiku, and Keʻanae, the Maui Invasive Species Committee (MISC) crew hikes day in and day out looking for and pulling miconia plants. The team is about to grow as a kaleidoscope of golden yellow butterflies descends to assist with control.

Miconia is a notorious invader of Hawaiian forests. A single plant can produce 8 million seeds. Miconia seeds grow quickly into large plants with huge leaves that block out the sunlight preventing other plants from germinating. Miconia’s shallow roots do little to stabilize the soil. Eventually, miconia becomes the only plant in the forest; invaded sites are known for landslides and erosion that muddies streams and buries reefs.

Sam Akoi III pulls miconia from the ground in 2003. The shallow roots make the plant easy to pull but miconia does a poor job holding soil. Invaded forest slopes are prone to erosion–MISC file photo

When biologists first found this invasive plant growing in Hawaiʻi, it was a call to action. Retired state forester Bob Hobdy helped address miconia in East Maui in the early 1990s. Initially, crews focused on the area above Hāna known as “the core,” but reports started pouring in from multiple locations across East Maui. “The idea of eradication [removing every plant from the island] was set aside,” says Hobdy. “It was not feasible.” The shrubby tree was scattered from Huelo to Kipahulu, with two major infestations in Nāhiku and Hāna. Too widespread to eradicate, but too damaging to ignore, the long-term solution was biocontrol: the researched introduction of a natural enemy specific to miconia that could lessen the impact and spread of the plant.

Over the last 27 years, crews have worked to contain this invader in the field. It’s been a success: miconia never reached the West Maui mountains and it’s rare to find a plant along Hāna Highway. Meanwhile, researchers in Hawaiʻi and South America have sought out and tested insects and plant diseases in hopes of finding something that will permanently undermine the plant’s invasiveness.

In 1997, ecologists released a fungus that eats holes in miconia’s large purple leaves. In Tahiti, this fungal natural enemy opened up the canopy so that other plants could grow, but fungus didn’t have the same effect here in Hawaiʻi. The search continued.

Tracy Johnson of the U.S. Forest Service has worked to find miconia’s natural enemies for 20 years. He’s hopeful about another miconia pests, a tiny yellow butterfly that lays its eggs on the leaves. The caterpillars hatch out and to dine on the umbrella-like leaves until they become adults. “Itʻs very specific to miconia,” says Johnson. “We know from observation in Costa Rica and in Hawaiʻi that it’s one of the most damaging insects to leaves of the plant.”

Miconia’s huge leaves are major problems: they act like tarps, shading out the understory, collecting raindrops and funneling them to the ground. In comparison, native ōhiʻa and koa trees have clusters of little leaves that break up rainfall into small drops that gently water the understory. The raindrops that roll off of miconia leaves are some of the largest measured They hit the ground with extra force—and since the ground beneath miconia is bare—they contribute to increased erosion. In fact, scientists have found that erosion is greater in a miconia-invaded forest than if the rain fell on bare soil.

“Itʻs (the golden miconia butterfly) very specific to miconia,” says Johnson. “We know from observation in Costa Rica and in Hawaiʻi that it’s one of the most damaging insects to leaves of the plant.”

Though only the size of your fingernail, the golden miconia butterfly could have a big impact on invasive miconia. Native to Costa Rica, these butterflies could be a welcome addition to miconia control efforts here in Hawaiʻi. — KENJI NISHIDA photo

Enter the golden miconia butterfly, Euselasia chrysippe, —a voracious leaf eater. Johnson and colleagues from the University of Costa Rica tested E. chrysippe with 73 different plants to see what the caterpillars would feed on. In a process called no-choice testing, caterpillars are placed in a petri dish with a leaf of the plant being tested. When forced to feed on other plants, they died; only Miconia calvescens and closely related plants in the melastome family can sustain them. This is good news since Hawaiʻi has no native melastomes.

After gorging on miconia, E. chrysippe caterpillars metamorphose into butterflies and seek out another miconia plant on which to lay their eggs. Like the MISC miconia crews, they’re really good a finding the pesky plant.

The golden miconia butterfly could help halt Hawaiʻi’s miconia invasion. But there is still more to be done. Johnson is investigating other potential natural enemies, particularly an insect that eats miconia seeds. Until a suite of effective and safe natural enemies exists to control miconia, crews from MISC will continue combing the hillside in search of miconia. Any sightings of miconia can be reported to MISC at 808-573-6472.

April 2020 Update: The Hawaiʻi Department of Agriculture is soliciting comments on the draft Environmental Assessment for the release of the golden miconia butterfly. Comments are accepted through May 26, 2020. HDOA press release

This article was originally published in the Maui News on July 8th, 2018, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles.

Why can’t you keep rabbits on the ground? “Rabbit fever” affects people

Posted on April 15, 2020 by Lissa Strohecker

Laws require rabbit owners in Hawaii to keep their pets caged and off the ground. This keeps pets from escaping to start wild populations and keeps them away from ticks that could spread a potentially deadly bacterial disease: tularemia.

Several years ago, a researcher working with sparrows at a rabbit farm on Maui fell ill. He was feverish and tired, then started getting sores on his skin. Doctors weren’t sure what it was and although he was never officially diagnosed, he responded to treatment for tularemia, a disease caused by bacteria carried by rabbits, rodents, and other animals.

Officially, tularemia has never been documented in Hawaiʻi. It’s difficult to culture the bacterium and handling it poses a significant infection risk to lab workers. “If not here, there is a real threat that tularemia could, at any time, be introduced into Hawaiʻi. It affects so many animal species, and once here, mosquitoes and other blood-sucking arthropods could spread it,“ says Fern Duvall, head of Maui’s Native Ecosystem Protection and Management program with the Department of Land and Natural Resources.

On the mainland, where tularemia is widely present, the disease is rare among people. They are exposed to the disease if they handle infected animals, or if bitten by ticks or another insect that fed on an infected animal. When bacteria come in contact with the skin, they cause ulcers that spread through the body, eventually reaching the lungs. If the bacteria is inhaled, the results can be deadly.

Occasionally, there are serious localized outbreaks of the disease. The summers of 2000-2001 saw nineteen cases of tularemia on Marthaʻs Vineyard, Massachusetts– one proved fatal. The Centers for Disease Control (CDC) came to investigate. An unusually high number (14 out of 19) were pneumonic (the bacteria had entered the lungs) and many involved landscapers. What the CDC suspected was that lawnmowers or other cutting tools struck the carcasses of dead, infected rabbits, the bacteria went airborne.

In 2015, there were outbreaks in Colorado, Wyoming, South Dakota, and Nebraska. The CDC theorized these outbreaks may have been triggered by increases in rabbit populations, which grew in response to more vegetation, caused by higher than normal rainfall.

If you see a rabbit running wild, report it: 643pest.org

Vegetation, rainfall, and landscapers are plentiful in Hawaiʻi – what we don’t have are populations of rabbits running wild–at least not yet.

According to state law, people can keep rabbits but they must be contained. If kept outside, rabbits must be in a cage off the ground. The penalties for noncompliance may reflect the seriousness of the threat: loss of your pet, fines, or even jail time.

Duvall says the natural predators of rabbits in Hawaiʻi–cats, rats, or mongoose–are unlikely to keep populations of wild rabbits in check. Rabbits evolved with a multitude of predators: weasels, coyote, bobcats, owls, hawks, snakes, foxes, and raccoons. To survive high mortality rates, they breed like, well, rabbits. The female (doe) can become pregnant with her first litter at 3 months of age, and again just a month later, within days of giving birth. One pair of rabbits can produce 100 kits (baby rabbits) per season, and up to 1,000 in a lifetime.

“We know they can become invasive,” explains Duvall. In 1989, six illegally released rabbits quickly became 100 at Hosmerʻs Grove in Haleakalā National Park. On Laysan, a small island in the Northwestern Hawaiian Islands, free-roaming rabbits ate the island bare in the early 1900s, likely causing the extinction of three bird species– Laysan miller bird, Laysan ʻapapane, and Laysan rail.

Beyond environmental impacts, rabbits running wild increase the risk of tularemia. “Rabbits are more often in contact with people,” explains Duvall. Whether as pets kept outdoors or released to the wild, more rabbits mean more rabbit-human interactions. Other pets can be affected: dogs, cats, and livestock can get tularemia from ticks or direct contact with an infected animal. Early treatment with antibiotics is critical.

You can help protect Hawaiʻi. If you have a pet rabbit, spay or neuter it. If you raise rabbits, keep them contained. If you see a rabbit running wild, report it. Call the Maui Invasive Species Committee at 573-6472 or report online through 643pest.org.

This article was originally published in the Maui News June 11th, 2017, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Find more Kiaʻi Moku articles.

Just the act of observing can help us and our island home

Posted on April 9, 2020 by Lissa Strohecker

The Hawaiian language reflects a close tie to the land. Connecting to nature can benefit both the health of the environment and the quality of life. — BRYAN BERKOWITZ / Maui Invasive Species Committee photo.

I ka nānā no ka ‘ike.
By observing, one learns.
‘Ōlelo No’eau #1186- Mary Kawena Pukui

The Hawaiian language includes over 200 words for rain with a subset of names specific to a place. Hawaiian rain names recognize that what falls from the sky can be delicate (lilinoe, kili, uaoa); windblown (lelehuna); showery (ua nuālu); cold (kili hau or ua ‘awa); or rainbow-hued (uakoko). The reddish ulalena rain falls on Haʻikū. Uakea mists Hāna. Winds can also be place-specific: the ʻakipohe wind nips Waiheʻe; the ʻimihau wind brings storms to Lahaina.

The language of Hawaiʻi reflects the deep relationship between people and nature. The original naturalists and resource stewards of Hawaiʻi – Hawaiians–have a keen understanding of their surroundings, from the terrain and weather to local plants and animals. This understanding is also reflected in place names. Hāiʻimaile translates to the blanket of the maile vine. Kanaio recalls the shrubby naio trees that once dominated the forests of the area.

Understanding of place was essential to the survival of the first island residents. And yet today, with the distractions of modern life, it’s easy to forget that a relationship to nature is still essential: both for our well-being and the health of the environment.

Recent research on the Japanese practice of shirin-yoku or “forest bathing” has demonstrated the health benefits of intentional time in nature. Observing the natural world elevates immune response and lowers blood pressure and stress levels. Forest bathing began in Japan in the mid-1980s and is now an integral preventative health activity there. Interest has spread to the United States, with forest bathing clubs forming in urban areas. Forest bathing is not hiking, nor does it have to take place in a forest. Practitioners go out into nature to experience, with all senses, their surroundings –the range of colors, the scents and sounds in the air, the feeling of sun or breeze on their skin.

Essentially, tuning into nature as a naturalist would.

Forest and Kim Starr, early detection specialists with the University of Hawaiʻi, are self-taught botanists, entomologists, and ornithologists. They often conduct inventories of a defined area, identifying the species of plants, birds, animals, spiders, snails, and insects present.

The view from Hana’ula looking towards ʻIao Valley. Pu’u Lio is the summit between Kapilau and Kalapaokailio ridge.

“When we are out there, we’re using all our senses,” says Kim. Cued in to bird calls while simultaneously scanning for the next plant species to add to the list, the Starrs are intently focusing on their surroundings. They often return to the same place repeatedly, documenting changes. Their efforts help resource managers find invasive species before they are widespread and causing harm in the environment.

What the Starrs do – tune into the world around them and note the changes – can be done by anyone. Like forest bathing and Hawaiian practice it simply requires paying attention to our surroundings and being curious. Training is not necessary, but repetition enhances the experience, both in better understanding what belongs and does not belong in the area and achieving the health-related benefits.

Spend time outside, it’s good for your health and Hawaiʻi.

Learn more about the names of the winds and rains near your home. This list of weather names from The Ka’imi loa o ka hihi Project is a good place to start. Discover a forest bathing practice of your own—find resources and information at www.natureandforesttherapy.org. As you deepen your connection with the natural world, you can help protect Hawaiʻi from newly arrived pests; report changes in your surrounding from potentially invasive species to www.643PEST.org.

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

Read more Kiaʻi Moku articles.

Fountain grass threatens dryland ecosystems

Posted on April 1, 2020 by Lissa Strohecker

Jared Clapper with Hāna Lima Land Management, working on behalf of Haleakalā Ranch, was part of a team responding to an infestation of invasive fountain grass in proximity to Pu‘uokali above Kīhei. Fountain grass has a reputation for fueling a cycle of brush fires and is one of the greatest threats to the remaining dryland forest ecosystems.

On the leeward slope of Haleakalā above Kīhei rises a red dirt cinder cone named Puʻuokali. Puʻuokali means “the hill of waiting,” and is said to be one of several mo‘o (lizard deities) who were transformed into cinder cones on the summit. From her prominent vantage, Puʻuokali watches over her daughter, Puʻuoinaina on the island of Kahoʻolawe. As visible as Puʻuokali is to Maui residents, she also has her secrets. Inside the cinder cone is an intact dryland forest – a representation of the most diverse and most threatened ecosystem in Hawaiʻi. This native oasis was forgotten about until the early 1980’s when a brush fire broke out nearby and biologists rediscovered the forest.

Dr. Art Medeiros, program manager for the Auwahi Forest Restoration Project, was one of those biologists. “Puʻuokali is amazing. It’s almost the only place from Makawao to Kaupō that looks like it did when Hawaiians were the only people here.” Wiliwili, lama, naio, koaiʻa, and ʻohe are the dominant trees of this forest – these plants were essential for early Polynesians but are virtually unknown today. Dryland Hawaiian forests are the most diverse of Hawaiian forests, yet they are virtually lost: an estimated 90 to 95% of dryland forest is gone. What remains is critical: 25% of endangered Hawaiian plant species are found in these tiny refugia.

In July of 2018, Byron Stevens of the Hawaiʻi Natural Area Reserves System passed over Puʻuokali in a helicopter and saw something that didn’t belong: a two- to four-foot-tall bunchgrass with wiry leaves and purple bottle-brush flowers. Fountain grass. He sounded the alarm to multiple conservation organizations.

Fountain grass starting to invade the sacred grounds of Puʻuokali on Maui. This area is one of the few remaining places that show how Hawaiʻi looked prior to western contact.

Fountain grass is an invasive weed rarely found on Maui. Native to North Africa, it’s targeted for eradication by the Maui Invasive Species Committee. The drought-tolerant grass is able to survive in some of Hawaiʻi’s driest areas; it poses a serious threat to native dryland forest. While rare on Maui, the alien grass now covers much of the leeward coast of Hawaiʻi Island. Introduced as an ornamental in the early 1900s, fountain grass has completely transformed the Kona side of Hawaiʻi Island, turning what was once bare lava with patches of native forest into fields of grass.

“Introduced as an ornamental in the early 1900s, fountain grass has completely transformed the Kona side of Hawaiʻi Island, turning what was once bare lava with patches of native forest into fields of grass.”

Dominating arid, bare lava is one thing, but this wiry bunchgrass can also advance into intact forest, in part because it survives brushfires. Fountain grass is fire-adapted; it can regrow after flames pass over then quickly flowers and set seeds to recolonize the area. In contrast, Hawaiian forests are not adapted to fires—native plants generally donʻt survive. Fountain grass is notorious for fueling and increasing fire. At one site on Hawaiʻi Island, fountain grass (ignited by humans) has increased fire frequency from once every 500-1,000 years to once every 6-8 years.

“Fountain grass is a direct threat to the Maui County sanctuary forests such as Puʻuokali, says Medeiros. Though surrounding areas have burned, Puʻuokali has not had any wildfire, hence why so much remains. This hidden forest survived over the years partly because the surrounding landscape was so barren. There was no fuel for brushfires, and less incentive for goats and deer to cross the cinder to reach the crater. “The last refuges [of dryland forest] are in these rocky areas,” Medeiros explains. The intrusion of fountain grass changes that.

Fountain grass is almost never found on Maui, but is extremely widespread on the leeward side of Hawaii island, where it has transformed the landscape and continues to spread. Any sightings of this invasive bunchgrass should be reported — identified by its purple bottle-brush flowers that turn white as they age. MISC file photo

With that in mind, crews from multiple organizations – Auwahi Restoration Group, Haleakalā Ranch, the Maui Invasive Species Committee, and the Plant Extinction Prevention Program – came together to remove over 1,000 fountain grass plants from Puʻuokali. Completing the work will take several years. Grass seeds cover the ground and recent rains will bring a flush of seedlings. But now that the infestation has been detected, it can be managed and eradicated.

You can help. Fountain grass is often used as an ornamental landscaping plant, and people sometimes plant it on Maui by accident. Seeds can be unwittingly transported interisland on hunting or golf gear. If you see fountain grass, take a photo and report it. You can contact MISC directly at 573-MISC (6471) or the statewide pest hotline at 643-PEST, or 643PEST.org.

This article was originally published in the Maui News on September 12th, 2018, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles. Find more information about fountain grass:

Species profile: Fountain grass
Report suspected populations of fountain grass: 643PEST.org

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Invasive jellyfish removed from Kaunakakai harbor

ʻŌhiʻa’s genetic diversity may contribute to disease resistance

Māmalu Poepoe Project traps and monitors invasive pests

Yellow-faced bees defenseless and vulnerable to predatory ants

Coqui frogs negatively affect the environment in more ways than one

Measuring the impacts of invasive plants in Hawai’i’s watersheds

Tiny golden butterfly could help halt miconia invasion

Why can’t you keep rabbits on the ground? “Rabbit fever” affects people

Just the act of observing can help us and our island home

Fountain grass threatens dryland ecosystems

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