Kia’i Moku Column — Page 5 — Maui Invasive Species Committee (MISC)

Safe biological controls rely on specialized species

Posted on March 19, 2021 by Lissa Strohecker

Living creatures can be grouped as specialists or generalists based on their strategies for finding food and habitat: generalists thrive in a variety of conditions and eat a range of foods; specialists rely on a particular environmental condition or a food type. For example, specialist species like koalas only eat eucalyptus leaves, Kamehameha caterpillars rely on māmaki, and our iconic ʻāhinahina (silverswords) are found only in high-elevation alpine environments in Hawaiʻi.

When researchers look for a biological control agent – another living species that can be used to reduce a pest – they look for specialist species. This is part of an approach that began over 40 years ago with the goal of reducing unintended impacts. It works. Since 1975, over 50 different biological control agents have been brought into Hawaiʻi. “There have been no unpredicted non-target impacts in that time,” says Darcy Oishi, the Biological Control Section Chief at the Hawaiʻi Department of Agriculture. He oversees the efforts to find, test, and release biological control in Hawaiʻi.

“We worry most about specificity,” says Oishi. Host-specificity, the relationship between the pest and the natural enemy, is the creed of modern biological control. By seeking out species that have evolved to be dependent on the target host, there is less risk that the natural enemy will have unintended consequences.

Wiliwili are endemic to the Hawaii Islands and are a keystone species in the dryland forest. Photo courtesy of Forest and Kim Starr

As new pests arrive in Hawaiʻi (and sometimes even before), the Hawaiʻi Department of Agriculture compiles lists of possible natural enemies, specialist species that could act to lessen the invasiveness and impacts of the pest in Hawaiʻi. Scientists comb through the scientific literature, call and visit natural history museums, and consult with entomologists and researchers worldwide, learning what species live in close association with the pest in its native habitat.

Exploratory entomologists then travel to the pest’s native range to collect candidates. Each potential natural enemy is studied further in its host range. After ruling out potential candidates, entomologists collect several species for additional testing.

Back in Hawaiʻi, the biological control agents are quarantined, raised and tested again for host specificity. In a process called no-choice testing, a potential agent is evaluated throughout its life stages to see if It will eat species it is likely to encounter in Hawaiʻi. For example, in introducing a biocontrol for a plant, the agent is isolated with other non-target plants to find out whether any unintended plants could be affected.

Researchers evaluate host specificity by looking at genetically related species as well as unrelated species that evolved similar characteristics to the target. For example, pasture-invading fireweed is in the aster family, but the phytoalkaloid – the toxic chemical that sickens animals – is what attracts one natural enemy, a caterpillar, to the plant. The caterpillar is tested to see if it can feed on related plants in the Aster family as well as those containing a similar toxic chemical.

Fireweed, *Senecio madagascarensis,* is a pasture invading pest that contains a chemical poisonous to horses and cattle. Photo by Forest and Kim Starr.

Until the 1970s, biocontrol agents were selected primarily based on the impact they would have on the pest, an approach that has unfortunately biased people against biological control today. Since then, though, rigorous selection and testing has gone into preventing unintended consequence. Another challenge is caused by misinformation; some invasive pests are inaccurately equated with biological control. For example, ʻōhiʻa rust, a leaf fungus that threatens our native ʻōhiʻa, decimated populations of rose apple, leading some to inaccurately assume it was an intentional introduction; instead, it was another of the thousands of unwanted pests that arrive in Hawaiʻi accidentally.

Modern biological control provides long-term, cost-effective, environmentally safe control of invasive species. It’s an essential tool in protecting Hawaiʻi from the impacts of widespread invasive species. Biological control does not eradicate a pest; it balances the equation to lessen the harm. The biological control for prickly pear cactus hasn’t eradicated it; the plant is still here, but instead of blanketing upcountry pastures it occurs in patches. Biological control saved the wiliwili trees of Hawaiʻi from decimation by a leaf gall wasp. The problem-causing wasp is still here but does less damage with the biological controls working to keep it contained.

Take time to learn more about biological control in Hawaiʻi and contribute to the decision-making process. Visit the Department of Land and Natural Resources biological control page at https://dlnr.hawaii.gov/hisc/info/biocontrol/

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 9, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Stopping both global pandemics and biological invasions requires flattening curves.

Posted on March 18, 2021 by Lissa Strohecker

In 2002, an unusually large and strange-looking chameleon turned up in a remote area of West Maui. The resulting media attention led to the detection of a population of the same species in Makawao. These lizards weren’t the familiar Jackson’s chameleons but a new and different species: veiled chameleons. These invaders, illegally introduced to Hawaiʻi posed a threat to our endemic forest birds and snails. Staff from the Maui Invasive Species Committee (MISC), Hawai’i Department of Agriculture and Department of Land and Natural Resources launched nighttime surveys, scouring the vegetation in the backyards of Makawao looking for these cryptic reptiles.

Veiled chameleons pose a risk to native birds in Hawaii. Thanks to community reports, these tree-dwelling arboreal predators were detected early and have efforts to eradicate them have proven effective. “Veileds” can be recognized by the shark-fin shaped casque on their head. MISC file photo.

During initial searches, the teams found chameleons quickly: they were distinctive, larger than their horned cousins and sporting a “shark fin” head, and clung to tree branches as they slept. The community helped by allowing searchers into their backyards and finding and turning in chameleons themselves.

In 2003, search crews and residents captured a total of 102 lizards, but over time, the numbers steadily declined. From multiple chameleons per night, searchers started to find only one or two per week. Then came months when crews came back from a week of searching without seeing a single chameleon. Searchers counted Jackson’s chameleons to stay focused on their task. As numbers continued to drop, the time between searches increased. The last capture was in 2008. In 2012, after a final search and outreach to the community, the agencies agreed: veiled chameleons had been eradicated from all known locations on Maui. Addressing the threat early, with community cooperation, prevented this species’ spread into new areas, including higher-elevation rainforests, the last habitat for our native birds and snails.

Both the language and processes used to stop an invasive species before it becomes widespread mirror the terms used to address a contagious and serious disease outbreak. As the COVID-19 pandemic spread worldwide and governments implemented social distancing measures, Jane Mangold, an invasive plant specialist at Montana State University, considered the similarities:

“One of the most obvious parallels is the importance of prevention, early detection, and rapid response. ‘Flattening the curve’ has been stated repeatedly by experts keeping us informed about the pandemic; the rationale behind this phrase is that by slowing the spread of the disease, medical providers will have more time and resources to treat those in need, and ultimately save more lives,” Mangold said.

Initially, reducing the spread of the chameleons was costly: routinely searching every few weeks to find chameleons faster than they could spread. So too for COVID-19, after months of social distancing and substantial economic impacts, the number of new cases has dropped and the curve has flattened. There are other parallels between controlling the spread of human disease and pests.

Addressing biological invasions early prevents later impacts.

Those last few chameleons were likely the most time-consuming and expensive to remove, but if crews hadn’t captured them, the population could have rebounded. Working past the frustration and searcher fatigue to find the few remaining individuals was critical to achieving eradication. While eliminating a small population of lizards is not readily comparable to addressing and suppressing a global health pandemic, similar elements lead to success: widespread cooperation, diligence, and commitment to seeing the effort through the long tail of the curve a resolution. And, of course, for both the chameleon and COVID-19, local reintroduction remains a possibility.

We can all do our part to maintain vigilance. And if you happen to see a strange chameleon with a shark-fin on its head while you are at home, report it to MISC at 573-6472 or through 643PEST.org. Anyone can turn in veiled chameleons and other illegally owned reptiles through the state Department of Agriculture’s amnesty program.

Learn more about the veiled chameleon at dlnr.hawaii.gov/hisc/info/invasive-species-profiles/veiled-chameleon/.

This article was originally published in the Maui News on June 13, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Native plant firebreaks may be a tool to control wildfires

Posted on March 18, 2021 by Lissa Strohecker

A few hundred feet from the traffic of North Kīhei road, native dragonflies swoop and dive, snatching their food mid-flight. The endangered aeʻo (Hawaiian stilt) and ʻalae keʻokeʻo (Hawaiian coot) probe the mud and vegetation for small shrimp while an ʻaukuʻu (black-crowned night heron) stalks fish for dinner. The coastal strand, salt marsh, and wetlands at Keālia Pond National Wildlife Refuge are thriving, thanks to the hard work of dedicated staff and volunteers who remove invasive plants, fence out feral animals, and plant native species in this 700-acre refuge. But decades of protection and restoration efforts almost disappeared in a puff of smoke.

In July 2019, 25,000 acres of central Maui burned in a series of brushfires that shut down roads and isolated communities as firefighters and helicopters worked through the night to put out the blaze. The flames burned right up to the edge of the Refuge, singeing trees.

Fire poses one of the greatest threats to restoration projects, particularly in dry, arid environments like South Maui. Hawaiian ecosystems and native flora are not adapted to fires – which are mostly human-caused. Invasive plants, such as fountain grass (Cenchrus setaceum), can fuel fire cycles by growing quickly and leaving behind piles of dry biomass, then germinating rapidly after a wildfire. Nonnative buffel grass and red top natal grass serve as kindling on Maui. With global warming, drought periods are predicted to become more common, fostering the conditions in which fires start and spread.

Fountain grass, a fire-adapted invader, fuels wildfires. Planting bands of native species that are resistant to a fountain grass invasion can help mitigate wildfires. Photo by Forest and Kim Starr.

Researchers are testing strategies in Hawaiʻi to limit the spread of wildfires in areas dominated by fire-promoting grasses. Green fire breaks – strategically planted strips of vegetation — have been effectively used in the continental U.S. as a complement to traditional firefighting methods. Water-rich and inflammable plants can help deprive wildfires of fuel, while also serving as habitat for other native species and a seed source for restoration projects.

“Greenstrips planted with natives can give added value to conservation areas,” explains Susan Cordell, a research ecologist with the US Forest Service and director of the Pacific Fire Exchange, is exploring how this technique can be used in Hawaiʻi with some of the native plant species used in dryland restoration. She evaluated several different species for their flammability and resistance to invasion – looking for ones that won’t allow fire-promoting grasses like fountain grass to take over. Her findings are offering restoration programs a host of options for the use of green fire-breaks.

ʻĀweoweo (Chenopodium oahuensis), a low-growing shrubby plant with a high-water content, stood out for its lack of flammability and resistance to invasion from fountain grass. The small glossy-leaved naio (Myoporum sandwicense) was also a contender due to its inflammability

“This isn’t a silver bullet,” cautions Cordell. “It’s just one tool in the tool-box.”

Bands of native shrubs could add a protective ring around the birds and their habitat at Keālia Ponds.

On Hawaii Island, Cordell and her team evaluated native plants’ suitability for use as a firebreak based on their resistance to invasion and lack of flammability. Photo courtesy of Susan Cordell.

Expand your knowledge about wildfires in the Hawaiian Islands: www.pacificfireexchange.org/hawaii. Learn more about Keālia Ponds National Wildlife Refuge: www.fws.gov/refuge/Kealia_Pond/.

Explore volunteer opportunities on the Refuge by contacting Keālia Pond NWR Visitor Services Manager, Courtney Brown at courtney_brown@fws.gov.

This article was originally published in the Maui News on July 11, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Rats triggered changes in the environment of Hawai’i prior to humans settlement

Posted on March 18, 2021 by Lissa Strohecker

Lo’ulu palms, like these pictured in the Kahanu Garden in Hāna, Maui, once lined the coast and sheltered understory plants in arid, windswept plains. Photo by Forest and Kim Starr

Palm trees and Hawaiʻi go together like fish and poi, right? Kind of. The coconut palms that line the beaches throughout the state are iconic, but are actually relative newcomers to the islands – one of the “canoe plants” brought to the islands by Polynesians. The only palms native to Hawaiʻi belong to the genus Pritcharidia. They won the sea-current lottery, arriving from the eastern Pacific near the Cook Islands and Tonga some 3.5 to 8 million years ago. Over time, the extreme isolation of the island chain led to the evolution of 23 to 27 endemic species, found only in the islands.

The first Polynesian voyagers arrived to find loʻulu groves lining the coastlines. These palms grew farther inland as well – in the wet rain forests, across wind-swept plains, and on arid leeward slopes. But within a single generation of the first humans, the loʻulu were mostly gone. To better understand when and why they vanished, scientists have peered underfoot, analyzing what was once wind-borne pollen.

The distinctive shape of a grain of pollen gives clues to its ancestry. The hard walls of pollen help preserve it in the fossil record. By examining layers of pollen deposited over time, scientists can better understand what plants formerly grew in an area.

In the late 1990s, researchers collected and analyzed soil samples from Oʻahu’s ʻEwa Plain, west of Pearl Harbor, to better understand the ecological history of the area. The ʻEwa Plain is arid and isolated from stream flow, providing a stable environment in which dirt and debris, including pollen and bones, accumulated over millions of years. The researchers were especially focused on evaporate ponds — areas where water collects after rainfall, then evaporates – and a sinkhole. Both are places with little disturbance that offer excellent conditions for soil sampling; sinkholes act as vaults for the bones of animals that fall in.

Huelo Islet off the coast of Molokaʻi is one of the few places in Hawaiʻi free of invasive rats. Loulu palms thrive there as they once did when humans first arrived in Hawaii. — FOREST and KIM STARR photo

From these collections of soil, pollen, and animal bones, the researchers read the story of the ʻEwa Plain. At one time, loʻulu stood tall, shrubby ʻaʻaliʻi and other plants formed the subcanopy. Huge, flightless moa nalo – goose-like ducks – and other land and seabirds had populated the area. The layers then reveal a plot twist – a sudden and dramatic decline in the loʻulu populations and the coincident arrival of a new character – the Polynesian rat (Rattus exulans) – their bones making a timestamp in the sinkholes. Other flowering plants, such as the low-growing ʻāweoweo, became dominant around the same time and bird populations plummeted. Only after the loʻulu population had collapsed do humans arrive in the area – as shown by deposits of charcoal. Rats, initially brought by people, spread across the landscape faster than the humans that introduced them. Early habitat alteration – the use of fire to encourage growth of grasslands for example – likely impacted loʻulu and native animals, but research findings from the ʻEwa Plain has led researchers to conclude that invasive rats likely catalyzed changes in vegetation that led to the initial decline in bird populations.

Today, loʻulu are still present but scattered, found in very low numbers. A mature loʻulu, one of the taller species, stands out – a distinctive marker in the forest. Cultivating palms in landscape settings may be possible by protecting protein-rich seeds from rats, but in the wild, species of loʻulu are increasingly rare and even endangered. The Hawaiʻi Department of Land and Natural Resources has designated seven palm species for protection through the Plant Extinction Prevention Program. Placement on the list means fewer than 50 individual plants remain in the wild. Offshore islets such as Huelo Islet on the North shore of Molokai offer a glimpse into the past, where loʻulu palms thrive on rodent-free islands. Conservation efforts in other countries have successfully eradicated invasive rats from islands to protect the native species that live there. New Zealand has set a goal of removing rodent predators entirely by 2050. There are efforts in Hawai’i to protect offshore islets and their rare plants and animals. Learn more about them at https://dlnr.hawaii.gov/removerats/

This article was originally published in the Maui News on August 8, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Quantifying miconia’s impacts; big leaves mean big water drops and high levels of erosion

Posted on March 17, 2021 by Lissa Strohecker

Miconia escaped cultivation to spread throughout East Maui. Containment rather than eradication is the goal for this invasive species on Maui and crews protect upper elevation watersheds by removing plants they find as they hike through the forest. MISC file photo.

On most weekdays, on the slopes and gulches above and below the Hāna Highway, a crew is hacking its way through the forest, spread out in a sweep line. They make slow progress through a mix of non-native and invasive plants: bamboo, inkberry, guava, and white ginger proliferate in this low-elevation forest. Somewhere in the midst of these forests is miconia, another non-native invader. The Hāna-based crew from the Maui Invasive Species Committee is here to find miconia and pull it from the ground.

Miconia may be found across a broad swath of the East Maui Watershed, from Kīpahulu to Huelo, but not as a continuous infestation. Dense pockets occur, especially in the area above Hāna town and in parts of Nāhiku, but elsewhere it’s patchy, thanks to decades of work to suppress and contain the infestation.

Large miconia leaves act as umbrellas, shading out sunlight. MISC file photo

Miconia should be an understory plant, as it is in the dark subcanopy of South Central American jungles of its native range. But in Hawaiʻi, open-canopy forests and the absence of significant “natural enemies” allow miconia to become the dominant plant. Invasive plants don’t just crowd out native plants and diminish habitat for native animals; they also can alter the landscape and ecosystem processes. A 2013 study on Hawaiʻi Island, by Kazuki Nanko of the Forestry and Forest Products Research Institute in Japan and University of Hawaiʻi professor Thomas Giambelluca, set out to dig a bit deeper into how miconia affects the ‘aina.

The team examined what happens on the forest floor when miconia takes over. Miconia’s leaves are huge – up to three feet long by two feet wide. These monstrous botanical solar panels help collect light in a dark understory in South America, but in Hawaiʻi they cast a deep shade, reducing the ability of native plants to capture the energy they need to thrive. Their study revealed that the amount of sunlight that reaches the forest floor is consistently lower in a monotypic miconia-invaded forest when compared to a native ʻōhiʻa-dominated forest, or forests invaded by a diverse mixture of plants. Additionally, miconia leaves decompose quickly, reducing the amount of leaf litter.

This study also investigated what happens to raindrops as they hit the forest canopy all the way down to the forest floor.

The giant leaves act like a tarp: water puddles before falling to the ground.

Miconia produces some of the largest leaf throughfall drops ever measured, with cascading impacts.

Unlike our multi-layered ʻōhiʻa forests, with their carpets of ferns and mid-canopy plants, miconia can develop into a one- layer stand. Larger raindrops, unimpeded by understory or leaf litter, gain speed, hitting the ground with greater kinetic energy than rain falling from the sky. Giant raindrops pound and compact bare soil, causing water to travel along the surface instead of filtering into the ground to recharge our aquifers. In some areas of miconia-invaded forest, bare roots and other signs of erosion tell the tale of how miconia is washing away our forest floor.

The scale of the East Maui miconia infestation has demonstrated that this plant is a formidable foe. Current efforts focus on keeping it out of upper elevation forest and preventing it from spreading farther west. Research and testing continue to find safe and effective natural enemies of miconia. Help us keep the raindrops in our forests. If you find a miconia plant on Maui, recognizable by its large green and purple leaves, report it to 643pest.org.

This article was originally published in the Maui News on September 12, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Citizen scientists and concerned community find ants new to Hawaiʻi

Posted on March 16, 2021 by Lissa Strohecker

The trap-jaw ant had never before been found in Hawaiʻi until a taro farmer in Hanalei collected it. Photo credit: Tom Murray, iNaturalist.org

In 2017, a taro farmer in Hanalei on Kaua’i found a strange ant in his lo’i – large and brownish red with mouth parts half the length of its head. Entomologists identified it as a species of trap-jaw ant, Odontomachus ruginodis, never before found in Hawai’i. Trap-jaw ants are aptly named: they can open their mandibles to a gaping 180° and, when nearby prey triggers tiny hairs on the inside, snap them shut at an astounding 140 mph, the second-fastest predatory animal movement known. According to Eric Garcia, an entomologist with the Hawai’i Department of Agriculture (HDOA), the ants find homes in composting wood. They will bite and sting but tend to flee when they see people or feel the ground moving, even using their snapping jaws to “jump” away.

The arrival of the trap-jaw ant to our state is relatively recent, but it has plenty of company. Nearly 60 ant species have found their way to Hawai’i, which previously had no ants. All have some impacts, with little fire ants (LFA) causing some of the greatest to date. Unlike trap-jaw ants, LFA are slow-moving, relatively oblivious of their surroundings, and unable to hold onto branches in a breeze. What they lack in aggression, they make up for in sheer number: supercolonies blanket trees and the ground, outcompeting other insects. When humans inadvertently encounter them, they leave with necks and torsos covered in welts from the sting of the ants. Pets can become blind from repeated stings. LFA are targeted for removal in Maui County, O’ahu, and Kaua’i.

Little fire ants are tiny! Only about 2 mm long. Image courtesy of Zach Pezzillo.

With over 20,000 different species of ants in the world, and a high dependency on imported goods, Hawai’i remains vulnerable to other troublesome ants hitchhiking a ride. Pest species that have recently invaded mainland states are particularly worrying.

The red imported fire ant (RIFA), native to South America, has spread throughout Texas and the Southeast. RIFA is very aggressive, swarming up people’s legs, leaving stings that can cause intense itching, swelling, and even anaphylactic shock. The tawny crazy ant, a relative newcomer to the Gulf Coast and southern states, excludes all other species, even covering itself in formic acid as a defense against RIFA. Poultry can die from attacks and cattle and other grazing animals suffer bites on their nostrils, mouths, and eyes. They are attracted to electrical wiring and tend to chew through the plastic casing and cause short circuits and, sometimes, fires.

What’s being done to prevent new invasions?

Inspectors stationed at the ports of entry check high-risk materials – ornamentals, food, and cut flowers – but the volume of incoming cargo limits their ability to inspect everything. Ants are small; many are found but sometimes they slip through. When they do, it’s often taro farmers, nursery owners, school kids, and beachgoers who find them.

The first detection of little fire ants in Hawai’i occurred when a Big Island nursery grower reported them to HDOA. On Maui, 11 of the 17 known infestations came to the attention of the Maui Invasive Species Committee through community reports. Students surveying for little fire ants as part of a class project found a species of ant new to Hawai’i – a tiny yellow LFA look-alike. Public reports of stinging ants at a Lāhainā beach lead to the first detection of the Mexican twig ant on Maui. Even RIFA and LFA were first detected on the mainland by kids: E.O. Wilson – a famed entomologist – collected RIFA in 1942 at age 13 in Alabama and a 12-year-old girl found LFA in Florida in 1924.

What can you do? Join in. This October, the Invasive Species Committees and partners throughout Hawai’i are encouraging people to collect and submit samples of ants from their yards during Stop the Ant Month. Think of it as doing a yearly physical for your home: collect and send in the ants you find to make sure there’s nothing to worry about. If something concerning pops up, early detection is on our side.

Collecting ants is easy; it just takes a smear of peanut butter and a few minutes.

Smear a tiny bit of peanut butter (or mayonnaise if peanut allergies are a concern) on several sticks, coffee stirrers, or pieces of cardboard, and place them in shady places in your yard. Set a timer for 45 minutes.
After 45 minutes, collect the ants, place them in a plastic bag labeled with your name, address, and contact information, and freeze them overnight.
Mail samples to MISC, P.O. Box 983, Makawao, HI 96768.

Indications of little fire ants include stings on the neck and torso that may resemble an allergic reaction. If you have experienced this, please contact us immediately: miscants@hawaii.edu or report it online through 643PEST.org. Find videos, lessons, and more information about invasive ants in Hawaiʻi at www.stoptheant.org.

A version of this article was originally published in the Maui News on October 10, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Research informs the efforts to stop Rapid ʻŌhiʻa Death (ROD)

Posted on March 16, 2021 by Lissa Strohecker

ʻŌhiʻa are a keystone species in Hawai’i and are found nowhere else in the world.

ʻŌhiʻa are the pioneers – the first trees to grow on bare lava. ʻŌhiʻa are also adaptable – they grow from sea level to tree line. ʻŌhiʻa are critical in capturing fresh water, supporting threatened and endangered species, and maintaining traditional cultural practices like hula. But these remarkable trees are at risk from Rapid ʻŌhiʻa Death (ROD), a disease that kills ʻōhiʻa trees. ROD has killed over one million ʻōhiʻa across Hawaiʻi Island. Diseased trees have been found on Kauaʻi, Oʻahu, and Maui. Already, hula hālau are staying out of the forests to protect ʻōhiʻa.

Since 2014, a team of highly dedicated scientists – ecologists, plant pathologists, geographers, and foresters – have been studying the origin, impact, and spread of the two newly identified species of fungus that cause Rapid ʻŌhiʻa Death (ROD): Ceratocystis lukuohia and Ceratocystis huliohia. Ceratocystis is a common – and sometimes devastating – plant pathogen, but these two species of Ceratocystis are new to science and new to Hawaiʻi.

Researchers Flint Hughes of the USDA Forest Service, Ryan Perroy of UH Hilo, Greg Asner of Arizona State, and others are using a combination of remote-sensing and field observations to gauge ʻōhiʻa death across Hawaiʻi Island. They have found that more trees are killed by ROD in areas where non-native hooved animals are present when compared to areas protected from those animals.

Invasive animals wound the bark of ʻōhiʻa, creating an entry point for the fungus. Damage from goats, sheep, and cattle is obvious – bark is missing. But the team also observed higher numbers of ROD-killed trees in forests with high pig populations. It is possible that pigs are damaging the roots of the trees opening it up for infection.

In a greenhouse study, pathologist Marc Hughes of the University of Hawaiʻi and the USDA Forest Service mulched potted ʻōhiʻa seedlings with sawdust made from infected trees containing Ceratocystis. The trees were healthy until Hughes cut some of the roots with a knife. Those trees then died, indicating that injuries to roots can also create opportunities for the fungus to infect trees.

“Wounds can only be infected for a short time. Once they dry out the fungus can no longer infect them. So protecting a forest helps, even if it has some ROD now” says J. B. Friday, extension forester with the University of Hawaiʻi Cooperative Extension Service.

Protecting the forests also helps ensure seedling survival. Ecologist Stephanie Yelenik of the USGS conducted experiments looking at what happens to ʻōhiʻa seedlings under ROD-affected trees, in plots where invasive plants and animals were removed and in plots where the pests remained. As seedlings died, researchers tested them for the presence of ROD – no sign of the pathogen was present. Seedlings were six times more likely to die in plots where invasive species were left unchecked. Invasive plants and animals posed a greater threat to the seedlings than ROD did during the study.

The first step in addressing ROD on Maui is to prevent it from arriving. HDOA has established a quarantine on the movement of ʻōhiʻa trees and plant parts from Hawaiʻi Island to other areas in the state. Hikers should brush off soil and clean boots or shoes with rubbing alcohol to remove any ROD-contaminated soil when traveling between islands.

Indiciations of ROD infection include a branch or tree dying quickly – within weeks.

Early detection, finding trees affected with ROD before the disease is widespread, is also key to protecting our ʻōhiʻa. Key signs include leaves that rapidly turning brown and appear frozen in place. On Maui, the only known ROD-affected tree was reported by an alert resident in Hāna. The tree has since been destroyed. The Hawaiʻi Department of Land and Natural Resources surveys our ʻōhiʻa forests looking for symptomatic trees. Conservation crews and Maui residents can report ʻōhiʻa trees that appear to have died quickly. To date, residents have reported fourteen suspect trees over the last year. Though ʻōhiʻa die for many reasons, including drought, injuries from mowers or yard equipment, and herbicide, reporting is essential to finding ROD-damaged trees early. Fortunately, aside from the one tree, all other samples collected from Maui have tested negative for ROD.

Help protect our ʻōhiʻa forests from rapid ʻōhiʻa death: Support watershed protection efforts to remove invasive plants and animals. Respect the inter-island quarantine. Keep reporting suspect ʻōhiʻa trees on Maui to MISC (573-6472) or through 643PEST.org. Join the ʻŌhiʻa Love Festival, November 16-21st. Sign up for the virtual event through rapidohiadeath.org.

This article was originally published in the Maui News on November 10, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Turn Off Lights at Night to Help Protect Seabirds From Invasive Predators

Posted on January 19, 2021 by Lissa Strohecker

Like many seabirds in Hawai’i, wedge-tailed shearwaters, ʻuaʻu kani, nest on the ground in rock crevices or in burrow. Once this chick’s adult feathers grow in, he will leave his burrow at night, navigating by the moon and stars. Artificial light can disorient young birds. Photo by Forest & Kim Starr.

“At one time there were so many seabirds in Hawaiʻi they blackened the sky” says Jay Penniman, manager of the Maui Nui Seabird Recovery Project.

Seabirds have been in Hawaiʻi for a long time, first arriving around 70 million years ago. The earliest colonists nested on what’s now known as the Emperor Seamount, the northwestern-point of the archipelago that has since eroded below sea level. These ancestral residents mated and reared their young, leaving behind nutrient-rich guano – seabird poop – that helped create soils. Guano nourished and promoted the growth of coral reefs, helping to develop a healthy marine ecosystem. Seeds of flowering plants arrived, sometimes carried in the feathers of the seabirds themselves, and the life on the Hawaiian Islands continued to develop.

As new islands emerged, seabirds continued to colonize them. Some species burrowed into cinder atop Haleakalā, others into dunes and the sandy soil along the coastline, still others in the dense tangle of uluhe fern in the rainforest. Isolation led to the evolution of unique species found nowhere else in the world. Clouds of seabirds helped lead Polynesian navigators to Hawaiʻi.

Once numbering in the milions, seabird populations today are a mere fraction of that. Seabirds nest in burrows, on the ground, or in the branches of low shrubs. After invasive predators – cats, rats, and dogs – began to roam the islands, the adults, young, and eggs too often became lunch or worse—killed for play. Young birds that survive to leave their nest face a different threat: artificial lighting.

For millennia, the night sky was lit only by the moon and stars. Fledgling seabirds would leave their burrows after sunset and navigate to sea using the reflection of the moon and starlight on water. Young birds remain at sea for four to five years until they return home to mate and raise their young.

Now, every fall, young seabirds fledge into an illuminated world. Man-made lighting shines into the night from streett lamps, porches, and stadiums, confuseing the inexperienced birds. They may circle for hours until they fall from the sky exhausted. Blueish-hued lights are particularly disorientating. For millennia, the light in the cooler blue wavelength meant schools of myctophids (lantern fish), the bioluminescent prey for the fledgling birds.

Seabirds played a crucial role in the natural history of the Hawaiian Islands, bringing seeds and nutrients that supported the colonization of life on and near the isolated islands. Photo by Forest and Kim Starr.

Penniman and his team work to tell local residents about the seabirds and respond to reports of downed birds during the fall-out season. One year he was at the Maui Raceway, picking up an petrel, that had crash-landed in the back of a pickup truck. As he gathered up the first bird, bystanders saw another one circling lower and lower. “It fell right at my feet,” says Penniman. “The bird was panting and its heart was racing.” Though able to wing across thousand of miles of ocean, the fledglings are exhausted and unable to move, making them easy prey for predators and at risk from passing cars.

Recovered birds typically spend the night in a pet carrier, then researchers weigh the bird and place a numbered metal band on its leg. In the light of day, they release the birds at the shore, where they fly out over the ocean to safety. Penniman has been working with these birds for 15 years. Those bands can help tell a happy ending: heʻs seen rescued fledglings return as adults, wise now to the distraction of man-made lights.

Cecelia “Cece” Frisinger lets a young ‘ua‘u (Hawaiian petrel) fly out to sea.

You can help. If you find a seabird, call 573-BIRD (2473) and someone from the Maui Nui Seabird Recovery Project will come to pick it up. Always keep pets contained and away from seabird colonies. Also, check your lighting. Penniman recommends the following to prevent outside lights from distracting fledging seabirds:

Lessen the intensity — use the minimum brightness necessary, measured in lumens,
Turn it off — use lights only when needed and consider installing a motion detector,
Point light down, away from the sky. Shields can direct light towards the ground where it’s needed most
Use warmer temperature, long-wavelength light, above 550nm.

Learn more about seabirds and the Maui Nui Seabird Recovery Project at mauinuiseabirds.org.

This article was originally published in the Maui News on December 12, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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Community urged to help protect yellow-faced bees

Posted on November 23, 2020 by Lissa Strohecker

Hawaiian yellow-faced bees rely heavily on an intact community of native plants to thrive in their communities. Often times they are avoidant of areas with a large population of non-native species. Photo Lahaina Photography

The adage “the more you look, the more you see“ is the basis for the “Pollinators in Paradise” project, a new approach to researching Hawaiʻi’s most important native pollinators: the yellow-faced bees.

As the primary pollinator in the Hawaiian Islands, these bees were once exceedingly common and found from mountain top to coastline. As they collected pollen to eat, these bees pollinated everything from silverswords to naupaka. Today, the Hawaiian yellow-faced bee populations are in decline and likely to become endangered unless the impacts of habitat loss, invasive species, and climate change can be addressed. Researchers are looking to the community for help in learning more about Hawaiʻi’s only native bees.

“Today, the Hawaiian yellow-faced bee populations are in decline and likely to become endangered unless the impacts of habitat loss, invasive species, and climate change can be addressed.”

“There are only a few researchers looking for yellow-faced bees,” says Dr. Jason Graham, one of the researchers and part of the “Pollinators in Paradise” project – a collaboration between Bishop Museum and Graham and funded by a Disney Conservation Grant. The goal of the project is to further Hawaiian yellow-faced bee conservation efforts through education and community involvement. “We hope to have more eyes out there looking for Hawaiian yellow-faced bees.”

The Maui Invasive Species Committee urges the general public to keep their eyes out for this native bee. Community members are also encouraged to download the iNaturalist app to track bee sightings in order to guide future conservation efforts. Photo Lahaina Photography

Built into the “Pollinators in Paradise” project is training: an interactive exhibit will be housed at Bishop Museum for visitors, there are educational kits available for teachers, and Bishop will use webinars to connect visiting school kids with scientists in the field. The ultimate goal is to have school kids and the community reporting sightings of yellow-faced bees through the online social networking application, iNaturalist. Anyone interested can participate.

Through iNaturalist, community reporters can submit photos of pollinators like the yellow-faced bees. Researchers will review and identify the pollinators. If yellow-faced bees are found, the sightings will be shared with resource managers to help guide future conservation efforts, and these bees need it.

Unlike honeybees, which form large social colonies with a queen and workers doing many tasks, including caring for young, yellow-faced bees are solitary nesters. Solitary bees lay relatively few eggs, stashing only a few dozen young inside a dead twig or in a hollow piece of coral on a rocky shoreline. They leave their young provisioned with food but unprotected from predators. This strategy served them well enough for the millions of years they spent in Hawaiʻi isolated from predators. Since human arrival in the islands, some 50 species of ants have made their way to Hawaiʻi (there are no native ants in Hawaiʻi). When ants find the vulnerable eggs and larvae, they feast.

There are over 60 species of yellow-faced bees native to the Hawaiian Islands. While some may not yet be listed as endangered, all species are in decline, with certain species not seen for 20 years. In October of 2016, seven species of yellow-faced bees gained protection under the Endangered Species Act. To protect what’s left, the scientists need to know more about them, a task that citizen-scientists can help with, once they know where to look.

Graham offers these tips for finding Hawaiian yellow-faced bees:

Look for native plants: The bees rely on native plants – with much of the islands’ native flora lost to development, agriculture, or taken over by invasive plants, their habitat is fractured. Yet they persist, and sometimes in the most unlikely of places – a patch of native plants growing on the shoreline near a resort for example.
Look for black bees: Yellow-faced bees do not look like the more familiar honeybee. Yellow-faced bees are slender, smooth, and mostly black, and much smaller than the pure black female carpenter bee, another conspicuous non-native bee common in the islands. Some but not all species have yellow on their faces that help identify them and lead to their unique moniker.

Anyone can participate in the “Pollinators in Paradise” project by downloading iNaturalist and joining the project through the app. Then start snapping photos of pollinators. Graham says cell phone cameras are sufficient for capturing images of the bees — videos work well because they can be paused to show the face of the bee, the key to determining the species. There are special lenses for photographing that clip onto the cell phone camera.

Learn more about the project through the Pollinators in Paradise Facebook page or the page on the iNaturalist application online.

This article was originally published in the Maui News on December 9th, 2018, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

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/

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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