Maui Invasive Species Committee
mauiinvasivespeciescommittee
The “yellow dragon disease” is perched on Hawaii’s doorstep
Tangerines, oranges, lemons, limes, pummelo and grapefruit— sharing a box of citrus just picked from the backyard is part of life in Hawai‘i, much as leaving your slippers outside the front door.
But imagine walking outside to find your trees covered in bitter, misshapen fruit: no more fresh lemons, tangerines, or oranges from your yard. Backyard gardeners and commercial growers across the mainland are scrambling to protect their citrus in the face of one of the most serious citrus diseases in the world, a disease perched on Hawai‘i’s doorstep.
Citrus greening disease, also known as huanglongbing or yellow dragon disease, originated in Asia. It was first detected in the United States in Florida in August of 2005. By July of 2008 it had spread across the state. It has since sprung up in backyards and farms throughout the Southern United States. Once infected, plants don’t recover and thousands of trees throughout the Southeast have died. The impacts to the citrus industry in Florida have been profound. California citrus growers are bracing themselves after the disease popped up in a Los Angeles suburb last summer.
A tiny, gnat-sized insect, the Asian citrus psyllid (Diaphorina citri), is responsible for spreading citrus greening disease. These psyllids feed on the stems and leaves of citrus and must feed on an infected tree to spread the bacterial disease. Currently, citrus greening is not present in Hawai‘i, but we do have sizeable populations of non-native Asian psyllid. Across the mainland the trend has been for the arrival of the psyllid to be followed by the disease.
The Asian citrus psyllid was first detected on the Big Island in 2006. Monica Tauyan is a plant pest
The pattern of “blotchy mottle” on this citrus leaf is an classic sign of a citrus greening infection. Photo courtesy of the University of Florida Institute of Food and Agricultural Sciences-Citrus Canker.
control technician with the Hawai‘i Department of Agriculture. She is part of a team that regularly surveys citrus across the state for citrus greening. Tauyan has no problem finding the Asian psyllid living on a variety of different citrus. “The psyllid causes leaf curl,” she says, “but the major concern is the disease.” If citrus greening arrives, the psyllids will carry the disease from tree to tree. Tauyan conducts surveys on Maui several times a year, and on Moloka‘i and Lāna‘i annually. Her efforts have been focused on farms, nurseries, and residences, and to date, have come up empty handed.
She’s looking for blotchy mottling on the leaves in an asymmetric pattern, “It’s the classic symptom.” according to Tauyan. When she finds this, or other indicators—such as yellowing leaves or misshapen, bitter fruit that don’t ripen—she collects samples and sends them to the University of Hawai‘i for testing. “We’ve been doing surveys since 2009. So far we’ve had no positives.”
If citrus greening makes it to Hawai‘i, Tauyan thinks it will likely arrive in the form of an infected psyllid. Psyllids carry the disease for life. A miniscule psyllid slipping undetected into Hawai‘i could spell big trouble for our citrus and inspectors with the Hawai‘i Department of Agriculture are on the lookout.
Malformed fruit also indicate and infection of citrus greening. Photo courtesy of the University of Florida Institute of Food and Agricultural Sciences-Citrus Canker.
You can help. First, don’t bring citrus plant material into Hawai‘i from the mainland or other parts of the world without first checking with the Hawai‘i Department of Agriculture. Secondly, regularly check your citrus. If the leaves are blotchy and mottled unevenly, or the fruit is misshapen and not ripening correctly your citrus could be infected. Confirming the diagnosis requires lab work, as there are also mineral deficiencies that resemble a greening infection. Contact Tauyan at the Department of Agriculture on O‘ahu 808-973-9528 if you are concerned about your citrus plants, or collect a sample yourself and submit it to the local extension office of the College of Tropical Agriculture and Human Resources in Kahului or Ho‘olehua on Moloka‘i. Submission guidelines are online at www.ctahr.hawaii.edu/dnn/yellowdragon/SampleSubmission.aspx. Learn more about the disease and find an app for reporting possible cases of citrus greening at www.saveourcitrus.org
By Lissa Fox Strohecker. Originally published in the Maui News, April 14th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
The crown-of-thorns starfish–despite the prickly reputation, this species is native to Hawai‘i, and beneficial to the reef
The crown-of-thorns starfish does munch on coral, but new research is showing that this species, native to Hawai‘i, benefits the reef. Photo courtesy of the National Oceanic and Atmospheric Administration
Proliferations of the spiny creatures can destroy 90 percent of a reef, as past outbreaks in Saipan, the Marshall Islands, and Guam have shown. In situations where the reef is stressed, an abundance of coral-eating starfish can trigger a cascade of changes. First the corals go, replaced by algal overgrowth. The resulting shift in fish populations can take years to recover. In Hawai‘i and Australia, concerns about crown-of-thorns outbreaks have focused on the reduced aesthetic value of the reef, and consequently, a decline in tourism. For some communities the reef is the icebox, and crown-of-thorns outbreaks can leave it empty.
But outbreaks rarely occur in Hawai‘i. Many crown-of-thorns starfish larvae die off, while adults are eaten by triton’s trumpet snails, stripebelly pufferfish, and harlequin shrimp. A healthy reef can support small numbers of prickly stars, and it’s probable that they benefit the reef in some way. According to Russell Sparks, aquatic biologist with the Department of Land and Natural Resources Division of Aquatic Resources, “In Hawai‘i, crown-of-thorns starfish feed on fast-growing, quick-to-settle corals, such as rice and cauliflower coral. These corals can overrun other species like lobe and finger coral, so a periodic bloom of crown-of-thorns could be an important way for reefs to maintain coral diversity.”
In 2004, marine biologists observed a crown-of-thorns outbreak in ʻĀhihi Kīna‘u. “Although the coral cover impacts were dramatic, the recovery seems to be well on its way,“ says Sparks. “It may increase overall coral diversity, which should make the reef more resilient to future disturbances.”
Until recently scientists hypothesized that crown-of-thorns outbreaks in remote locations such as Hawai‘i, Guam, and French Polynesia resulted from an influx of larvae from elsewhere in the Pacific. In Australia, massive starfish outbreaks spread south along the reef in waves, seeded from larvae upstream. But new research indicates that Hawaiian blooms occur within the native population. A team of scientists from the University of Hawai‘i-Manoa looked at the genetics of crown-of-thorns starfish and found that these supposed “invaders” were actually locals—they weren’t some rogue population from across the Pacific. What does this mean?
Crown-of-thorns outbreaks are not fully understood. The species may be acting invasively because of human interference. Some biologists theorize that heavy rainfall and coastal nutrient runoff contribute to a higher than normal survival rate for larvae, resulting in a larger number of adults. Over-harvesting of the species’ natural predators could be another potential trigger. Researcher Dr. Rob Toonen recommends that marine wildlife managers “seriously consider the role that environmental conditions and local nutrient inputs play in driving crown-of-thorns outbreaks.”
You can help scientists learn more. The citizen-monitoring project Eyes of the Reef relies on reports from regular reef users to monitor reef health. Crown-of-thorns sea stars are one species of focus. Early detection of outbreaks is critical to protecting the reef. Report any occurrence of 20 or more crown-of-thorns starfish through the Eyes of the Reef monitoring project at reefcheckhawaii.org/eyesofthereef.html
By Lissa Fox Strohecker. Originally published in the Maui News, March 10th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
Conservation-Helping the Economy and the Environment
Darryl “Kanamu” Tau‘a was an East Maui tour bus driver who lost his job during the decline in tourism post September 11, 2001. Imi Nelson, a recent Hāna High graduate, was looking for work that would keep him close to his family. That fall, in response to the economic downturn, the Hawai‘i state legislature appropriated $1.5 million to create an emergency environmental workforce that put 450 people back to work. Kanamu got a temporary job controlling miconia, a South American tree invading the East Maui watershed. Imi joined the dengue fever response crew, helping to eliminate the environmental conditions that foster disease-spreading mosquitoes. Later, when the Maui Invasive Species Committee (MISC) had openings on its Hāna miconia control crew, both Kanamu and Imi had the necessary field experience. They landed permanent jobs—hard to come by in rural Hāna.
Conservation means jobs and those jobs mean new skills. Kona Ball and Darrell Aquino of MISC prepare to rappel down a cliff while Robert Vincent of East Maui Watershed Partnership looks on.
Conservation means boots on the ground and fingers on the keyboard. In Hawai‘i, it means jobs for thousands of people throughout the state, from Hāna to Honolulu, Hilo to Hanalei. Local suppliers and contractors provide goods and services for conservation projects, further multiplying the benefits of dollars spent. Natural resource work in Hawai‘i brings an estimated $456.6 million to the economy as wages, goods, and services, according to a report on the Green Industry from the University of Hawai‘i Economic Research Organization. Funding comes from a variety of federal, state, county, and private sources, with the bulk spent employing an estimated 3,275 people working in the field or office. In addition to wages, these jobs as technicians, researchers, hunters, construction workers, data managers, grant writers and accountants, educators, and managers often provide extensive training and skill-set development opportunities.
University research highlights other economic benefits of conservation work, which protects our water supply, food, beaches and reefs, and makes Hawai‘i a great place to live and visit. Natural resource management safeguards more than just native birds, plants, and insects. Almost all of the water Maui County uses is captured from rainfall, and a healthy watershed is key to maintaining adequate and safe water supplies. Economists estimate that if the Ko‘olau watershed on O‘ahu was rendered unusable and no longer contributing to the aquifer, the loss would be between $4.57 and $8.52 million.
Conservation jobs have been somewhat insulated from the turmoil of employment in the tourism sector. Despite a decline in
A conservation worker learning to attach an external load to a helicopter.
state job growth of 1 percent over the last five years, jobs in natural resources have increased 1.5 percent. People working in natural resources think that jobs will increase modestly, an opinion likely shaped by concerns about the current state of the economy. In Hawai‘i, where we rely on the environment for so many things, there is plenty of work to be done. Approximately 800,000 acres across the main Hawaiian Islands are in some kind of active conservation management, though there are an estimated 1,900,000 acres of healthy native ecosystem needing protection.
Nelson and Tau‘a continue to live in a rural community, in part because they have jobs in conservation and have learned skills during their employment. Investments spent protecting our environment translate into jobs today and healthy resources for future generations. To find out more about green industry in Hawai‘i check out the Green Growth Report by the University of Hawai‘i Economic Research Organization online at www.uhero.hawaii.edu.
By Lissa Fox Strohecker. Originally published in the Maui News, Feburary 10th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
Maui Activities for Invasive Species Awareness Week
It’s Hawaii Invasive Species Awareness Week and on Maui, we’re focusing on ant awareness (more activities to follow).
What do you know about the little fire ant? Here’s a change to test your knowledge and win some great prizes. Teachers-here’s an activity for you and your students!
Tune into KPOA 93.5 & KISS 99.9 March 4-8th for the Spot the Ant & Stop the Ant contest from the Maui Invasive Species Committee and the County of Maui.
Be ready to answer the trivia questions (all information from fireantfreemaui.org) on-air for a chance to win one of these great prizes from our sponsors:
- One night at the Ritz-Carlton, Kapalua
- One night & brunch for 2 at the Kaanapali Beach Hotel
- A round of golf for 2 at the Makena Beach & Golf Resort
- All you can eat prime rib & seafood buffet for 2 from the Makena Beach and Golf Resort
- A sunset dinner cruise for 2 from the Pacific Whale Foundation
- $100 gift card for tickets from the Maui Arts & Cultural Center
- 6-line canopy tour for 2 from the Piiholo Ranch Zipline
- Hana-Haleakala A star tour for 2 from Blue Hawaiian Helicopters
- $100 gift card for Ruby Tuesdays in Kihei *
*Special thanks to the Hawaii Islands Land Trust
Think you have little fire ants on your property?
On Maui test & send in a sample to Maui Invasive Species Committee, PO Box 983, Makawao, HI 96768
Traveling by boat? Swab those hulls and propellors to stop invasive stowaways.
Each year over ships make over 1000 trips to Hawai‘i. Container ships and barges, fishing boats, cruise
Organisms colonize an anchor chain. Photo courtesy of Hawaii DLNR-DAR
ships, and sailboats, aircraft carriers and military ships come bearing cargo for Hawai‘i or stop over on their way across the Pacific. Any of these boats could carry tiny stowaways from distant places, and that has resource managers concerned. Even an interisland boating trip could translate into trouble for your local reef.
“The majority of Hawai‘i’s aquatic invasive species came in via ballast water and hull-fouling,” explains Sonia Gorgula, the state coordinator recently hired by the Hawai‘i Department of Land and Natural Resources’ aquatic division to address the problem. Ballast water is taken by ships at sea or in port to maintain stability, and can contain organisms or larvae that may be harmful when released into a new environment, oftentimes thousands of miles from where they originated. Hull-fouling, or bio-fouling refers to the plants and animals that grow on any aquatic vessel, be it ship or yacht, dingy or dock. When these living organisms reach new waters, they can cause problems.
Of the two types of marine contamination, Gorgula says biofouling is the bigger worry in Hawai‘i. One species introduced this way is snowflake coral, a fast-growing soft-coral from the Caribbean. Since arriving in Hawaiian waterways, it has devoured the zooplankton that supports the marine food web and destroyed numerous black coral colonies. Hypnea, the rank invasive algae that washes up on Maui beaches, spread between the Islands attached to the underbelly of a fishing or sailboat. Hypnea is not only stinky and expensive to deal with on the beach, it outcompetes native limu.
Biofouling happens on any type of vessel, ocean or freshwater, that remains in port or dock long enough for organisms to become attached. “Broadly speaking it’s mussels, algae, barnacles,” says Gorgula. “When you start to see an assemblage become quite dense, you can even find crabs.” Boats function as floating reefs, transporting these aquatic aliens to Hawai‘i, where they may or may not find a home.
“Some species arrive and establish, then fail. Yet many species become invasive here that were not thought to be invasive until they get here,” says Gorgula. “Often there’s not enough information to predict what will become invasive.” One way to approach the situation is to treat all biofouling as harmful and focus on prevention—keeping boats with Hawai‘i on their itinerary free of small stowaways.
Biofouling is a drag, literally. Barnacles colonize the hull of a ship and reduce fuel efficiency as well as pose a risk of becoming invasive. Photo courtesy of Hawaii DLNR-DAR
Most commercial ships have incentives to keep hulls relatively free of growth; biofouling creates drag that reduces fuel economy. But other hidden “niche” areas underneath the boat—propellers and intake pipes used to pull in water for cooling the engine and fire-fighting—often house alien species. Cleaning the hull is part of regular boat maintenance; focusing on niche areas will help prevent the spread of hitchhikers. Certain paints are designed specifically to discourage fouling, and hidden spots can be painted as well as hulls, simple steps that feed into regular maintenance.
Policies and regulations for ballast water are well established worldwide, but biofouling has only received attention of recently. One of Gorgula’s tasks is to develop policy to protect Hawai‘i. “The biofouling policy issue is complex,” she says. “Around the world, only California, New Zealand, and Australia have developed policy. Globally, there aren’t many people working on it. We’re forging new territory” In 2007 the state legislature approved rules requiring ships planning to release ballast water to exchange the water first in the open ocean more than 200 nautical miles out to sea, reducing the likelihood ballast water will contain organisms that could find safe haven in Hawai‘i
It may seem trivial n a world of big ships and global transportation, but paying attention to the details can
A diver inspects a propeller for biofouling. Photo courtesy of Hawaii DLNR-DAR
make a big impact. Every boat, even those going interisland can help stop the spread of invasive aquatics. “Clean off biofouling in the same port where it accumulated,” says Gorgula. Be sure to clean your hull, anchor, props, bilge compartment, and any associated gear in the same watershed to prevent its spread to other watersheds and islands.
By Lissa Fox Strohecker. Originally published in the Maui News, January 13th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
From paper maps and memory to GPS units-the evolution of technology in invasive species control
GPS-enabled field computers help pilots and crews record where they’ve already surveyed and where they need to go.
If smart phones, tablets, and global positioning systems (GPS) are on your wish list, you are not alone. These gadgets are proving essential in the efforts to protect native Hawaiian ecosystems.
Accurate mapping has always been crucial to surveying for and controlling invasive species. Back in the mid 1990s Maui field crews first began finding miconia. Though not very long ago, the technology available then seems pre-historic today. Using altimeters and orienting from known physical landmarks, they would record plant locations by drawing dots on photocopies of topographic maps. These paper maps were filed away for future use. Subsequent visits meant more hand-drawn maps. Sometimes the only way to find a specific locale was to bring along someone who had been there before.
Early attempts to create electronic maps involved scanning topographic maps into a computer and then drawing dots to estimate locations using computer programs intended for design and drafting. There was an electronic record, but it was time consuming to create and not especially accurate.
Then along came the GPS, promising a precise reading of position and time anywhere on earth, in any type of weather, provided the receiver had an unobstructed view of 4 satellites. Early GPS units were expensive and heavy. Accuracy was, well, not all that accurate. That unobstructed view of satellites was often hard to come by given terrain and canopy cover—especially in Maui’s dense rain forest, where miconia was spreading. To record a position, field crews carried a pole that they had to piece together and snake up through the overhanging tree limbs. With luck and patience, they could get enough satellites to provide a reading and not lose the antennae in a tangle of branches.
Rather then depending on paper maps and memory, field crews now load maps onto GPS units that allow them to record where they control plants and guide them to where they need to search.
GPS receivers have improved dramatically. Now field crews load maps onto GPS units and follow pre-recorded trails to locate remote populations of invasive plants. Rather than relying solely on the memory of a few people, crews can be dispatched to remove plants even if no one among them has visited the area before. Hand-drawn maps are a thing of the past, transforming an unwieldy stack of maps into a few digital files, making it possible to track work on hundreds of thousands of miconia plants.
Helicopters survey vast areas for invasive plants while flight lines are recorded on GPS units to ensure thorough coverage. Spotters in the aircraft record precise locations of plants so crews can revisit the locations either on the ground or by air. Each helicopter has a GPS-enabled field-rugged laptop loaded with maps to help guide the pilots and spotters.
Even flight following has changed dramatically. Pilots and crew used to have to stop what they were doing and radio in every 20 minutes to let managers know they were safe. Often, terrain blocked radio calls and pilots had to spend valuable time flying to an area where they could make contact. Now flight followers back at headquarters can monitor the helicopter’s whereabouts and status using a computer program synchronized with the GPS unit on the aircraft.
Technology has helped to increase efficiency and effectiveness of field crews on Maui and now these tools are in the hands, or pocket, of anyone with a smart phone. While plans are in the pipeline for invasive species reporting apps specific to Hawai‘i, there are many other options for reporting invasive and rare native species. If you are a cell-phone shutterbug you can easily send photos to email addresses-just type in an email where you would normally enter a phone number. You can also report online via the reportapest website at reportapest.org. So next time you see plant or animal that causes you to raise an eyebrow just snap a photo and send it in and stay posted for future tools to help you learn more about the plants and animals in your backyard.
By Lissa Fox Strohecker. Originally published in the Maui News, December 9th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
Plants Out of Place–Native to Hawaii but Invasive Elsewhere
The native Hawaiian ecosystem is often described as fragile and prone to invasion, so it may come as a surprise to find that some of our island species on the most unwanted list of invasives in other parts of the world.
Native to Hawaii, naupaka, or Scaevola taccada , invades a beach in Fort Lauderdale, Florida. Naupaka chokes out plants native to Florida and may alter nesting habitat for sea turtles. Photo courtesy of Forest & Kim Starr.
In Hawai‘i, beach naupaka decorates miles of coastline, but in Florida this attractive plant is listed as a state noxious weed. Known as Scaevola taccada to the scientific community, naupaka outcompetes the endangered Scaevola plumieri native to Florida. In the Caymen Islands in the Carribean, where naupaka is also invasive, there is some concern that sea turtles may not be able to access nesting sites with mounds of naupaka blanketing the coasts. Naupaka was introduced to Florida as a landscaping option.
Pōhinahina is another Hawaii coastal native that’s proven invasive elsewhere. Crews on the coast of North Carolina remove this dune-destroying shrub. Photo courtesy of beachvitex.org
In Hawai‘i, pōhinahina, Vitex rotundifolia, sometimes known as beach vitex, grows alongside naupaka but it’s wreaking havoc elsewhere. Pōhinahina is a sprawling coastal shrub with small purple flowers. Landscapers introduced pōhinahina to the Southeastern and Mid-Atlantic States, where it now smothers coastlines, choking out native plants like the endangered sea beach amaranth. Pōhinahina is a noxious weed in North Carolina. Virginia has enacted a statewide quarantine in hopes of stopping its spread. Communities gather regularly to fight back this kudzu of the coastline.
This ‘a‘ali‘i grows on the slopes of Haleakalā, but it has also taken over rangeland in Kenya. Photo courtesy of Forest & Kim Starr.
‘A‘ali‘i, or Dodonaea viscosa, is another hardy Hawaiian native that’s problematic elsewhere. This drought tolerant plant grows in central Maui and up the slopes of Haleakalā. It’s a tough shrub with distinctive winged seedpods, and, as it turns out, doesn’t taste so great–at least to the cattle of Kenya and Uganda, where ‘a‘ali‘i takes over rangeland.
Like many of Hawai‘i‘s native plants, these species are indigenous to Hawai‘i, meaning that they are native to Hawai‘i as well as other places. Naupaka is native throughout the Pacific and India, growing on coastlines from Okinawa to Oman and from Micronesia to Madagascar. Pōhinahina’s native range stretches across the Pacific Rim and into Southern Asia. And ‘a‘ali‘i is a cosmopolitan species found from Florida to the Sonoran deserts into Mexico and across the Pacific to New Zealand and Australia.
These three plants have developed ways to spread their keiki far and wide: plentiful seeds that float and survive a long bath in salt water. ‘A‘ali‘i seeds spread inland by catching the wind and by sticking to the feathers of birds. These strategies help explain why these plants are native to such a huge area, and how they were able to reach Hawai‘i. But when these plants are released from the checks and balances found in their native habitat–competition with other species, predation by insects, even climate and geography–there’s a possibility of a problem.
An invasive plant is not inherently bad; it has developed strategies necessary for its survival. In Hawai‘i these three plants play an important role–protecting beaches from erosion and providing habitat for native animals. However, what constitutes a means to survive in one place can translate into an invasive characteristic elsewhere. It’s just a matter of the right plant in the right place.
By Lissa Fox Strohecker. Originally published in the Maui News, November 11th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
Ants and Hawaiian Seairds–A Totally Unnatural Combination
The Hawaiian archipelago is crawling with ants and not a single one belongs here. Humans
A petrel is covered by big-headed ants on Kure Atoll. While ants can be a nuisance for people, the insects can maim or kill nesting seabirds.
SHELDON PLENTOVICH photo
introduced over forty-five ant species to the islands. While they’re a nuisance to people, to Hawaiian seabirds they are a major problem.
Sheldon Plentovich is the Coastal Program Coordinator with the Pacific Islands Fish and Wildlife Office. She has studied some of these impacts. “Seabirds nesting in Hawaii do not have effective defenses against dense supercolonies of invasive ant species,” she says. And even though high densities of invasive are present, the seabirds return to the same areas to nest as they have for generations.
In March, throughout Hawai‘i, Wedge-tailed Shearwaters dig burrows for nesting along the coastline. Unfortunately tropical fire ants, Solenopsis geminata, often inhabit these areas. Plentovich isn’t sure whether the ants are trying to eat the birds or if the ants are just defending their nest. Adult birds can fly away to escape the ants but the chicks can’t. “They’re programmed to stay in the nest,” explains Plentovich. In their fury, the six-legged invaders destroy the tender webbing on the chicks’ feet. These ant attacks affect the development of the chicks as well. Oftentimes chicks that have been attacked fail to grow feathers.
Plentovich knocked back the population of tropical fire ant on one islet off the coast of O‘ahu and, as expected, found that the seabirds had greater fledgling success compared to those on an islet still infested by tropical fire ant.
Tropical fire ants attack a wedge tailed shearwater chick on islet off Oahu. These attacks can permanently disfigure birds’ feet and even lead to chick’s death. Photo Sheldon Plentovich
Tropical fire ants belong to a group designated as “tramps.” Tramp ants are omnivorous, and because they do not compete between colonies, form dense supercolonies made up of multiple queens. These dense supercolonies can outcompete everything else for food and resources. And since it takes a queen to start a new colony, the greater density of queens makes it easier for these ants to be spread around by people. Not surprisingly tramp ants include some of the Pacific’s most devastating invasive species, such as the little fire ant. They’ve hitched rides to the furthest reaches of the Hawaiian archipelago.
Johnston Atoll is one of the most isolated atolls in the world, 860 miles west of Hawai‘i. The Atoll is strictly a wildlife refuge where red-tailed tropicbirds nest alongside shearwaters, petrels, terns, noddies, and boobies. Unfortunately the atoll has become a haven for the yellow crazy ant or Anoplolepis gracilipes. This tramp ant doesn’t bite or sting the birds, rather it sprays them with formic acid and birds don’t respond well to formic acid. Animals that can seek out fish from the sky are left with swollen puffy eyes. Plentovich has seen Red-tailed Tropicbirds that have “toughed it out” staying to nest despite being swarmed by ants, spraying formic acid.
Footage of a Red-tailed Tropicbird swarmed by yellow crazy ants on Kure Atoll. These invasive ants swarm nesting seabirds and spray formic acid. Seabirds show high nest fidelity and return to the same location to rear their young despite the presence of these ants. Video by Sheldon Plentovich
Ants impacts can vary from place to place. The big-headed ant, Pheidole megacephala, is one of the most common ants in Hawai‘i. On Moku‘auia off Oahu, eradicating big-headed ant had no effect on the hatching and fledging success of shearwater chicks. But on Kure Atoll the
Big-headed ant attacks Bonin Petrel chick on Kure Atoll. Big-headed ants are one of the most common ants in Hawaii but on Kure the population reached such a high density the ants were attacking everything in sight. Photo by Cynthia Vanderlip
Chances are people inadvertently brought ants to isolated Johnston and Kure Atolls. All it takes is a single queen ant in a piece of cargo to start an infestation. And eradicating an established infestation is extremely difficult work. Plentovich is hopeful that new techniques will lead to the eradication of yellow crazy ant on Johnston atoll where other techniques have been unsuccessful. She’s seen how controlling an invasive ant can influence the whole ecosystem. When she reduced the population of invasive ants on offshore islets she saw an increase in the diversity of insects and “native plants survived better-the ‘ilima started taking off.”
By Lissa Fox Strohecker. Originally published in the Maui News, October 14th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
A hidden world in Maui’s streams
After 27 years of working with the Department of Land and Natural Resources, aquatic biologist Skippy Hau has become pretty familiar with Maui’s streams and the creatures dwelling in them. But there are always surprises. Several years ago, Hau discovered
This hīhīwai, a native Hawaiian snail, clings to a rock in a Maui stream. The presence of slow-movnig hīhīwai can indicate the frequency and quantity of water needed for a healthy stream.
hīhīwai, one of two species of native Hawaiian freshwater snails, crawling single file up the cement bottom of a channeled stream next to a West Maui grocery store. The stream is typically dry, with few rocks to shelter the hīhīwai, but there they were.
It’s amazing that Hawaii has any native freshwater species to begin with. Streams in Hawai‘i are 2,400 salty miles away from the nearest continental sources of freshwater. Yet fish, crustaceans and mollusks colonized island waterways well before the first Polynesians arrived, most evolving into species found no where else in the world. These animals have evolved to cope with intermittent stream flow and climb waterfalls. ‘Ōpae kala‘ole, an endemic crustacean, is the best climber of all, known to scale 100-foot cascades. But like other native Hawaiian plants and animals, these riparian creatures now face threats from introduced species.
Invasive armored catfish have added the eggs of the native ‘o‘opu (goby) to their diet. Guppies and mosquito fish devour Hawaiian stream dwellers’ larvae and contribute to the decline of native damselflies at low elevations. Swordtails and other non-native aquatics spread new diseases to native fish. Tilapia compete with native water birds for food and released pet turtles dine on ‘o‘opu.
‘O‘opu nōpili. Photo by Skippy Hau
‘O‘opu nākea in ‘Iao stream. Photo by Skippy Hau
Most of these invasive species were intentionally introduced – starting with Asian immigrants bringing in Chinese catfish, rice-paddy eels and other
‘O‘opu ‘alamo‘o. Photo by Skippy Hau
species for food in the 1800s. Mosquito fish, or topminnows, were released into streams from the 1900s through 1960s to control mosquitoes. This was an era when state officials frequently introduced game species, such as trout, bass and tucunare, or peacock bass, into streams. During the 1970s, managing resources for native species became more important; game fish are no longer introduced.
In the 1980s and ’90s, aquarium fish and mollusks began appearing in Hawaiian streams. In addition to guppies and swordtails, a variety of cichlids and ramshorn snails now snack on larvae of native stream animals returning to the ocean. Aquarium owners who dump unwanted pets are the most likely source of this problem, which is ongoing.
Hīhīwai, like all Hawaiian stream dwellers, are only part-time residents. They spend the first year of life in the ocean, then ascend single file into a freshwater stream. Not all make it as they colonize the stream’s upper reaches, instead becoming a source of food for other riparian species. In addition to the hīhīwai, another native mollusk, five species of fish and two crustaceans spend a part of their lives in the ocean. During rare flood events, these freshwater animals move quickly upstream for the less salty part of their lives, finding shelter in upper elevation pools.
Hau regularly monitors the slender tributary of ‘Iao where he first witnessed the climbing snails. When it exceeds a trickle, he dons a snorkel mask and peers under rocks for slow-moving hīhīwai. By carefully studying Maui’s streams, Hau has documented the frequency and volume of water necessary for our native freshwater animals need to move between ocean and stream.
These remarkable aquatic animals need our help. Don’t release unwanted pets into streams. If your fish is too large for your aquarium, contact a local pet store. They often take back fish and snails. Consider selling or gifting your unwanted fish or turtle online or to a friend.
Learn more about the fascinating animals in Hawaii’s streams and how to help protect them at hawaii.gov/dlnr/dar/streams.html.
By Lissa Fox Strohecker. Originally published in the Maui News, June 10th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
Know an invasive-species-savy landscaper or nursery?
The Maui Association of Landscape Professionals, Maui Invasive Species Committee, and the County of Maui will recognize a professional landscaper, plant provider, or commercial/agricultural property owner’s efforts to protect Maui County from invasive species.
The 10th Annual Mālama i ka ‘Āina Award winner will be announced at the MALP Lawn and Garden Fair, November 3rd, at the Maui Mall. Nomination forms are available below or by calling 573-MISC or visiting http://www.mauiisc.org or http://www.malp.org.
Application Deadline is Saturday October 20th.
2012 Malama i ka `Aina Award On-line Application
2011 Malama i ka Aina Award Winners Elaine Molina and Sarge McBride (center with plaque and lei) and presenters (from left to right) Rob Parsons with the County of Maui, Teya Penniman and Pat Bily with MISC, and Gary Mohrlang with the Maui Association of Landscape Professionals.
2010 Malama i ka Aina Award Recipient Mach Fukada
The ‘Ua‘u and the threat of invasive species
Hawai‘i is famous for rare birds: scarlet honeycreepers that dart through the rainforest and gold-flecked owls that hunt at twilight. But another Hawaiian bird lives most of its life at sea. The ‘ua‘u , or Hawaiian petrel, returns to land under the cover of darkness—and then only to nest. Now is the time to be on the look out for this cryptic bird; the chicks are fledging.
An ‘ua‘u chick hides in his burrow awaiting his parents return. In the meantime the chick is vulnerable to passing rats, cats, and mongoose who can quickly scoop the chick from his hiding place.Photo by Jay Penniman
Named for their eerie nighttime call, “uuua-uuuu,” the ‘ua‘u alight on land for only a few minutes before ducking into their underground burrow. Their nesting locations are remote, difficult to access. Counts at sea estimate the population at around 20,000, low enough to earn a place on the Federal Endangered Species list.
Fossils indicate that ‘ua‘u were once so plentiful in Hawai‘i they blackened the sky. Prior to humans’ arrival in these Islands, ‘ua‘u and their feathered friends ruled these Islands. ‘Ua‘u built burrows from the coastline to the mountaintop, digging into soil and taking advantage of existing crevices. But populations have dwindled to a fraction of what they were, due to habitat loss and predation. Now invasive species threaten to overrun the sliver of habitat remaining for native birds, while predators lurk outside their burrows.
Having evolved without mammalian predators, ‘ua‘u are particularly naïve, both in their choice of nesting location and how they rear their young. Ground nesting, even in a burrow, leaves petrel chicks and eggs vulnerable to attacks by stealthy rodents or felines. Pigs, goats, cattle, deer, and people trample burrows, crushing the egg or the chick inside.
‘Ua‘u only lay one egg per season, and both parents invest much energy and effort in rearing the chick. A trip to the grocery store for an ‘ua‘u parent is a two-week, 6000 mile journey along the northwest Hawai‘i an islands to the Aleutians and circling back down to Hawai‘i , among the longest feeding routes of any known seabird. Unfortunately, there is no babysitter; the chick’s safety depends on remaining underground, hidden from predators.
While the species as a whole demonstrates remarkable flexibility in choosing nesting sites—from dense thickets of uluhe fern to frigid cliff faces on the summit of Haleakalā –individual birds are guided by habit. They return to the same burrow year after year, despite the likelihood of a cat laying in wait.
Many people are working to protect the ‘ua‘u . Biologists arelearning more about these remarkable birds by observing their burrows and tracking their movements. A major colony was re-discovered on Lāna‘i in 2006, but the birds’ native habitat was being choked out by invasive trees. To protect this colony, staff from the Lāna‘i Native Species Recovery Program and volunteers are fighting back acres of strawberry guava and replanting the uluhe fern that form a protective blanket over the burrows. Within Haleakalā National Park, park staff controls predators that attack ‘ua‘u .
‘Ua‘u, like this one, are often disoriented by streetlights and end up on the ground. If you find an ‘ua‘u safely pick it up and call the Maui Nui Seabird Recovery Project, (808) 280-4114. Photo by Jay Penniman
You can help as well. When petrel chicks leave the burrow for their first time they can become disoriented by the bright lights of civilization. Some birds come crashing down onto buildings or roads. A grounded chick is defenseless against predators and threatened by cars. If you see a petrel on the ground, carefully pick it up with a cloth or towel and place it in a well ventilated box. Do not try to feed the bird. Call Maui Nui Seabird Recovery Project (808) 280-4114.
By Lissa Fox Strohecker. Originally published in the Maui News, September 9th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
Fast-growing ivy gourd threatens rare dryland ecosystem on Maui
On Maui, we are lucky to have so many open spaces. Our island is relatively undeveloped, though you
Ivy gourd can be identified by the 5-petaled flowers and green fruit that turn red as they ripen, hanging like Christmas lights from the plant. Photo by MISC
may beg to differ when you’re stuck in traffic. The majority of the population lives along the coastlines. This distribution of island residents is nearly identical to the distribution of ivy gourd; a highly invasive vine found growing in central, south, and west Maui. And, as development expands, so does the population of ivy gourd. This is no coincidence.
Native to Africa, India, and Southeast Asia, ivy gourd was probably brought to the Hawaiian Islands by an immigrant from one of those areas. The immature fruit of the plant, as well as the young shoots, are used in cooking. Many recipes from Southeast Asia call for ivy gourd. While it may taste good in a stir fry, it’s in poor taste—illegal even—to have the plant growing in your yard.
Inevitably, the vine escapes cultivation. Humans—and their pesky rodent counterparts—have been the vectors for spreading ivy gourd. Rats scamper off with a stolen fruit spreading the seeds. In absence of the insect pests that limit ivy gourd’s growth in its native habitat, the plant grows unchecked. Roots form every time the branching vine touches the ground. Each root is enlarged, giving ivy gourd the ability to survive lengthy periods of drought.
Ivy gourd, Coccinia grandis, can be hard to identify without the flower or fruit present. The leaves are broad and flat, shaped like an angular heart, about 2.5 inches wide. They are arranged in an alternating pattern along the vine. The flower is white, with 5 petals curving out of a tube-like base. If the plant reaches the fruiting stage, the 3-inch long fruit, dangling like bright red Christmas lights, is a dead giveaway that the vine smothering your yard is ivy gourd.
Ivy gourd is fast-growing. While we don’t know the actual rate of growth on Maui, it is a member of the cucumber family of plants that may grow up to 4 inches a day. If we ignored this aggressive growing vine what would happen? “We’d be ivy gourdians” a 7th grade student so aptly replied during a class visit by MISC. When people don’t consume ivy gourd, ivy gourd consumes the environment around us. Trees, power poles, fences, even cars disappear beneath a mountain of vines.
The fast-growing ivy gourd can easily smother trees, fences, and power lines. It could transform the native dryland ecosystem, choking out rare Hawaiian plants and leaving nothing but curtains of green. Photo by MISC
Ivy gourd is currently limited to residential areas on Maui. MISC’s successful control of the population depends entirely on the cooperation of property owners and residents. Because the vine grows so fast, and because the seeds germinate so quickly after a rain, monthly site visits may be necessary. A plant can go from seedling to seed-bearing within as little as a month, and once the plant produces seed, the seed bank can last for years. Field crews must find and apply a few drops of herbicide to every single root in order to kill the plant, no small task when the plant has covered several kiawe trees.
On the islands of O`ahu and Hawai’i, ivy gourd is invading natural areas. On Guam and Saipan, ivy gourd is so established that the only way to limit it may be through biocontrol. Insect pests have been released in these areas. On Maui, control efforts have reduced ivy gourd to a level that would no longer support a viable biocontrol population. The only way to eradicate it is to get rid of the remaining plants, monitor locations for new plants, and prevent new introductions.
If a plant nursery is infested with ivy gourd, it’s almost inevitable that seeds and plant material will be spread in contaminated soil. This may help explain why we find ivy gourd in golf courses. A huge infestation was discovered on Lāna‘i in 2006, and with continued effort the population is being knocked back.
And those open spaces on Maui? Above the development of Lahaina and Kīhei are the remnants of the native dryland forest ecosystem. The leeward slopes of Haleakalā, where this ecosystem was once predominant, still harbor stands of native trees. This is where ‘iliahi (sandelwood) grows. The wiliwili tree can be found here, as well as the naiotrees that gave us the name for the area: Kanaio. These areas have been greatly altered by ranching and the introduction of goats and deer, yet they still include rare native plants and insects. There is no ivy gourd here. Ivy gourd would thrive here if introduced into
these native forests. Ivy gourd would smother the existing vegetation, leaving curtains of green where there once were diverse and rare ecosystems.
Help us protect these rare ecosystems on by finding and reporting ivy gourd in Maui’s residential and rural areas. Do not grow ivy gourd. If you suspect you may have ivy gourd on your property, please call the Maui Invasive Species Committee at 573-MISC (6472) and we will remove it, free of charge.
The nose knows: dogs sniff out invasive species
A beagle with the U.S. Customs and Border Protection inspects passengers luggage in an airport. The Hawaii Department of Agriculture has done similar work with dogs in the past; a recent bill passed by the Hawaii State Legislature will help bring the program back. Photo by James Tourtellotte.
This fall there will be some new faces at the Hawai‘i Department of Agriculture (HDOA)– furry faces. The Hawai‘i Detector Dog Program is returning, thanks to restored funding from the state legislature and matching federal funds. Alongside their human handlers, these four-legged inspectors will screen incoming cargo and luggage on O‘ahu to help prevent plant and animal pests from becoming established in Hawai‘i.
Hawai‘i’s detector dogs will be sniffing for brown tree snakes that may have stowed away in shipments from Guam, but they will also inspect other cargo arriving at both the Honolulu airport and O‘ahu military bases, including mail and parcel shipments.
The 20 year-old program was cut in 2009 due to a lack of funds. Prior to the program’s demise, busy beagles and handlers bagged seven snakes in a 14-15 year period. During inspection blitzes at the Maui airport, dogs uncovered more than a thousand instances of undeclared produce and vegetation, including a shipment of persimmons infested with mealybugs not known to be in Hawai‘i. Hawai‘i’s airport dogs also serve as ambassadors for HDOA, letting passengers know with a friendly wag that their luggage was inspected behind the scenes as well as in the baggage claim area.
The new inspectors will be in good company. Man’s best friend, long called upon for helping humans in search and rescue, hunting, and police work, now is lending a nose on a variety of conservation fronts.
Kristine Lesperance and Dexter hunt the invasive rosy wolf snail in the Waianae Mountains of Oahu. Photo by Oahu Army Natural Resource Program.
Kristine Lesperance of O‘ahu Detection Dog Services and her lab-mix named Dexter have been working hard to save native Hawai‘i an tree snails, or Achatinella,in the Wai‘anae Mountains. Dexter sniffs out invasive animals that prey on native tree snails: the cannibalistic rosy wolf snail and Jackson’s chameleon. Dexter can distinguish between a rosy wolf snail, a giant African snail, and native snails by scent. When he finds one, he sits down and waits for his reward. He can track chameleons by the smell of their scat, a definite advantage for finding these cryptic creatures.
Lesperance says dogs are great for determining the presence or absence of an animal across large areas. Depending on the species the dog is searching for and how odoriferous it is, it may take awhile. With the rosy wolf snail, Dexter doesn’t cue into the scent until he’s one-half inch to two inches from the snail, taking up to 30 minutes to find one; he does better with Jackson’s chameleon scat, finding it from several feet away, but, when working as a search and rescue dog, Dexter can smell a person a quarter mile away.
In Missoula Montana trainer Dalit Guscio is about to reward Seamus. He’s been tracking down invasive Dyers woad plants. Seamus and Dalit are with the Montana-based Working Dogs for Conservation. Photo by Elizabeth Stone.
In Montana, dogs are sniffing out invasive plants in the field, outperforming their human counterparts at finding scattered small plants. Elsewhere, dogs are finding bees, pythons, rare plants, cane toads, tortoises, termites, and even root fungus. “I think we could use dogs to find pretty much anything that has a scent,” Lesperance says, adding that further work will help determine how dogs can be most effective in different conservation scenarios.
Although dogs have been trained to help in conservation for 10-15 years, “we’re really just seeing the beginning” says Lesperance. Our new four-legged recruits will help close gaps in agricultural inspection, but many opportunities exist for canine eco-detection services. Who knows whose nose will be hard at work protecting Hawai‘i?
By Lissa Fox Strohecker. Originally published in the Maui News, August 12h, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
A changing climate and the plight of the ‘i‘iwi
An adult ‘i’iwi sips nectar form the flowers of a native lobelia in the Waikamoi preserve. The habitat for the i”iiwi and other Hawaiian honeycreepers is threatened by climate change. As climate warms mosquitoes that transmit disease to the native birds will increase in range. Photo by Forest and Kim Starr
On just about any given day you can find ‘i‘iwi, among the more charismatic species of Hawaiian honeycreepers, flitting around Hosmer’s grove, just past the entrance to Haleakalā National Park. These energetic little bursts of red flit from tree to tree feeding on the nectar of ‘ōh‘ia flowers and the occasional spider or insect. Once abundant on all islands from sea level up into the mountains, these brilliant birds are now rarely seen lower than 5000 feet. Below that elevation, avian malaria, a bird disease transmitted by mosquitoes, has decimated Hawaiian honeycreepers. Today, even the birds subsisting in the high-mountain pockets of habitat are threatened—not only by invasive plants and animals, but also by climate change.
Avian malaria is not new in Hawai’i . Migratory birds carrying malaria regularly visited Hawaiian shores—but before mosquitoes were introduced, the disease had no way to infect resident bird populations. In 1826, sailors on the whaling ship Wellington dumped barrels of mosquito-infested water into a Lahaina canal. That marked the beginning of the end for low- and mid-elevation native honeycreepers.
Since then, mosquito-born diseases have caused two major waves of extinction in Hawaiian honeycreepers. Native forest birds have shown scant resistance to foreign diseases. Those that survive inhabit forests above the “mosquito line,” where neither mosquitoes nor the diseases they carry can thrive. In cooler temperatures, avian malaria can’t reproduce fast enough to infect birds. Thus the largest populations of ‘i‘iwi dwell in the cloud forests of East Maui and Hawai’i; the birds are increasingly rare or nonexistent on islands without tall mountains. ‘I‘iwi have vanished from Lāna‘i and only a few remain on Moloka‘i and West Maui. With a warming climate, the remnants of disease-free habitat may shrink or disappear.
Introduced mosquitoes, such as the tiger mosquito above, transmit avian malaria and pox from non-native birds to native birds. Having evolved in isolation, native birds lack resistance to these diseases. Photo by James Gathany, CDC
And Hawai‘i is heating up. Each decade since 1975, minimum nighttime temperature has increased an average of almost 1°F. Nighttime temperature is the determining factor in estimated elevational range of avian malaria. Over the last 50 years, the mosquito line has steadily marched up the mountain, from 2000 feet in the late 1960s to nearly 5000 feet today.
Climate change may affect our native birds in other ways. Summer storms are predicted to become more frequent, creating more habitat for mosquitoes during their optimum breeding season, increasing their density and the likelihood of transmission of avian malaria. Meanwhile, overall rainfall may decrease, compromising the health of the native Hawaiian rainforest and the inhabitants that rely on it.
The ‘i‘iwi is not the only bird likely to be chased out of remaining habitat by avian malaria and climate change. In Hawaii all of our non-migratory birds, such as the Maui crested honeycreeper or ‘ākohekohe, Maui parrotbill or kiwikiu, and the ‘apapane, face the same danger. These species are unique among the world’s creatures; they exist nowhere else on earth. Many of them are highly significant to the native Hawaiian culture and all play critical roles in their natural environments. Their loss would be devastating.
In response to concerns raised about the ‘i‘iwi’s perilous situation, the United States Fish and Wildlife Service is proposing to list the ‘i‘iwi as federally threatened or endangered, with climate change noted as a factor in its decline. How can you help? Support efforts to address the causes of climate change. Work to protect the remaining natural areas that shelter ‘i‘iwi. And take a trip to Hosmer’s Grove to witness just how spectacular these winged treasures are.
By Lissa Fox Strohecker. Originally published in the Maui News, July 8th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series http://www.hear.org/misc/mauinews/
Check out the MISC Summer 2012 Newsletter: Kia’i i Na Moku o Maui Nui
Click this link for a PDF version of the newsletter: 2012 MISC Newsletter Kia’i i na Moku o Maui Nui
In this issue:
Moeana Besa and her family live in a part of Tahiti plagued by little fire ants. Photo by Masako Cordray
Moeana’s Message―What Tahiti Can Teach us about Little Fire Ants
“This place used to be paradise” said Moeana Besa. Find out what happened.
On Page 1
Fire at the Farm
How Christina Chang helped stop the establishment of the little fire ant on Maui.
On Page 3
On the Job
Where can you find a snake handler, exploratory entomologist, educator, advocate, law enforcer, pesticide applicator examiner, irrigation specialist, and ant wrangler? Try the Hawaii Department of Agriculture.
On Page 5
New Science
Paintball guns, scuba tanks, and spacklers—the promising new techniques for treating little fire ants.
On Page 6 (check out the video of the spackler in action!)
Tiny Ants, Huge Nuisance
Learn more about the little fire ant and why this wee creature is such a big problem
On Page 6
Education Saves the Day!
How a class visit led to the detection of the little fire ant on Maui.
On Page 9
Dauntless Darrell
MISC field crew leader Darrell Aquino is up for any challenge
The keen eye of Darrell Aquino, pig hunter and dedicated MISC employee.
On Page 10
PLUS:
- MISCommunication-The Comics of Brooke Mahnken
- Managers Corner
- Is that fire ant Little? Tropical? or Red Imported? Dr. MISCellaneous knows the difference!
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Learn more about the little fire ant at lfa-hawaii.org or littlefireants.com
Report little fire ants
