A year-round staple in our islands will soon take center stage on many Thanksgiving dessert tables. The sweet potato is often overlooked, with favor leaning towards the more popular pumpkin pie. Still, its origins weave a fascinating history which include Poynesian voyagers, territorial farmers, invasive species, and celebration of African American culture . Follow the journey of this humble root in Hawaii and beyond.

The sweet potato (Ipomoea batata) is a part of the morning glory family and can grow from sea level to over 2,000 feet. The root (potato) is high in carbohydrates, beta-carotene, and vitamins, and the edible leaves are high in protein, making it an ancient and modern-day superfood. It grows in a variety of soils and withstands drought, making it a staple in ancient Hawaiʻi. Hawaiians had developed over 250 varieties of sweet potato- ʻuala in Hawaiian- which ranged in color from yellow, orange, red, purple, and white. Its importance is emphasized in the ʻŌlelo Noʻeau (Hawaiian proverb) “He ʻuala ka ʻai hoʻola koke i ka wī (The sweet potato is the food that ends famine quickly). But how did uʻala get here?

Using DNA analysis, French researchers from the Center for Functional and Evolutionary Ecology found that Hawaiʻiʻs sweet potato originated high in the South American Andes mountains. To get an accurate sample of pre-contact potatoes, they analyzed the dried remains of ʻuala from Captain James Cook’s voyages in 1796. They traced the genetic blueprint of these samples to Ecuador and Peru. In addition to indigenous, archaeological, and linguistic knowledge, ʻuala’s genetic evidence showed that Polynesian voyagers interacted and traded with natives in South America. After the Hōkūleʻa’s worldwide voyage from 2013-2018, the ability of ancient Polynesian voyagers to make a trip like this was no longer up for debate; however, the humble sweet potato offers further evidence that these highly skilled ancient wayfarers were able to make a journey of this magnitude.

ʻUala was an essential famine food and crop in ancient Hawaiʻi but was also significant to modern economies. Commercial cultivation of sweet potatoes first began in 1849. In 1919, it was grown as one of the top ten emergency foods during the World War (replacing white potatoes and used as livestock feed). But, despite being extensively cultivated in Hawaiʻi, the ancient Hawaiian varieties were being lost. By 1923, only 70 known species remained. Today, there are only about 24.

By the 1990s, just over 1,000 acres of sweet potato were in cultivation in Hawaiʻi, generating over $7 million for the economy. In 2016, farmers had less than 500 acres in sweet potato statewide, generating just under $2 million.

 The reason why? Pests –  primarily sweet potato weevils. These ½ inch, ant-looking insects are the most significant pests to sweet potatoes worldwide. The larvae channel the potato roots, and high concentrations can result in hundreds of larvae feeding on just one potato. This makes the potato unmarketable and inedible (the root becomes bitter in response to the pest damage). Sweet potato weevils are not the only potato plagues- the sweet potato bug, leaf miners, vine borers, hornworms, and nematodes are others. There is hope though. Researchers at the University of Hawaiʻi at Mānoa have recently discovered two Hawaiian varieties showing promising results in flavor, yield, and pest resistance. Perhaps the sweet potato may become an agricultural staple in Hawaiʻi yet again.

As a staple on the holiday dinner table, sweet potato pie is widely beloved. Although indigenous peoples cultivated sweet potatoes in the Pacific and the Americas centuries before the first Thanksgiving, sweet potato pies as a holiday tradition stems from Southern plantation kitchens, baked by enslaved African Americans. After emancipation, recipes followed freed peoples throughout the country, remaining a holiday favorite in African American communities today. But the love of sweet potato pie reaches far and wide and has made its way back to Hawaiʻi. Try this tropical twist on the traditional sweet potato pie this Thanksgiving: a Sweet Potato Haupia Bars recipe by Maui-based Instagram and YouTube cooking star Relle Lum (@keeping.it.relle) at keepingitrelle.com/sweet-potato-haupia-pie-bars.

Serena Fukushima is the public relations and education specialist for the Maui Invasive Species Committee. She holds a bachelor’s degree in environmental studies and a graduate degree in education from the University of Hawaii at Manoa. “Kia’i Moku, Guarding the Island” is written by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that threaten our islands’ environment, economy and quality of life.

This article was originally published in the Maui News on November 12, 2022 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles

Citizen scientists have been key to finding most of the little fire ant (LFA) populations on Maui. Without their reports, Maui likely would not have a chance to stop this destructive ant from taking over our island. Ant submissions from concerned residents have also been key to understanding which species are already on the island. In order to understand Maui’s ants better, Monte Tudor-Long, Little Fire Ant Crew Member with the Maui Invasive Species Committee (MISC) compiles records of ants collected through MISC surveys and community reports. “MISC has collected over 40 species of ants- just about every ant known to exist on Maui.” Tudor-Long says.

All the ants in Hawaiʻi are thought to have been brought here by humans. Over 60 species are now present. Ants are considered “ecosystem engineers” altering soils, nutrient cycling and decomposition, and food chains.  They are effective and aggressive predators. Here in Hawaiʻi, many have become invasive, causing harm to the animals not evolved to defend themselves against non-native pests.

Tudor-Long believes that identifying Maui’s ants can lead to the early detection of harmful, new species. “If every household on Maui sent in samples of their ants, it would create a citizen science-based research repository that could help inform future conservation decisions,” he says. Public submissions can help find new ant species not yet known to be in Hawaiʻi. They are also vital in detecting new little fire ant populations, a MISC target because of the harm they cause. In fact, 13 of the 19 existing LFA infestations were reported by the community.

Tudor-Long encourages folks to observe the ants around them and send them to MISC (request a free collection kit at stoptheant.org). He’ll reply with the identification of the ant, and if LFA is detected, MISC will control the infestation. October is also Stop the Ant Month, and folks who send ants to MISC this month are entered into a raffle to win prizes. Here are some common ants that Maui residents may see and some invasive ones that Maui has a chance to stop:

Target Ants- Report to MISC at (808) 573-6472
The little fire ant (Wasmannia auropunctata) or LFA damages economies, harms native wildlife, pets, and livestock, and prevents people from spending time outside. The only way to confirm the identification of LFA is by examining them under a microscope. The ant’s venom, which is delivered by multiple stings at once, leads to an itchy, burning sensation that can last for hours or even days.  LFA are slow-moving and unaggressive. This arboreal ant literally rains down on people as they brush past infested foliage. LFA are not widely established on Maui and should be reported to MISC.

The red imported fire ant (Solenopsis invicta) or RIFA has not been detected in Hawaiʻi and should be reported to MISC. Plaguing the southern United States, RIFA are exceedingly aggressive, attacking with painful stings. The hope of controlling and eradicating this ant will require early detection of its arrival. Says Tudor-Long, “If it arrives under the radar and we fail to notice right away, it will spread rapidly throughout the drier, sandy lowlands of Maui.”  For this reason, samples of tropical fire ants, a lookalike species, should be routinely collected and sent to MISC to make sure it is not RIFA.

Common Ants on Maui- Not controlled by MISC:
The Hawaiian carpenter ant (Camponotus variegatus) is the largest ant in the state- up to half an inch long. Winged males and females fly when mating, often swarming toward lights. They are nocturnal, do not sting, and mostly leave people alone.  The Hawaiian carpenter may nest in wood cavities but does not damage wood. Carpenter ants are one of the first ant species ever documented in the islands, first recorded by entomologists in 1879.

Tropical fire ants (Solenopsis geminata) have been tormenting beach-goers in Hawaiʻi since the mid-1800s. These aggressive ants sting the feet and ankles of any passerby near their nests. Tropical fire ants are red and can reach up to a third of an inch.  Compared to little fire ants, these ants are gigantic – up to four or five times the size of LFA.  Slow-moving LFA are nearly invisible, while fast-moving Tropical Fire Ants are quite easy to see swarming on your bare feet. 

The African big-headed ant (Pheidole megacephala) was one of the first ants to be introduced here. By the late 1800’s it wiped out scores of endemic insect species as it mowed its way through Hawaiʻi’s native forests. You can find these ants just about everywhere in Hawaiʻi up to around 3,000 feet elevation. They bite our legs and feed on non-native insects like the larvae of houseflies. This species makes small ant hills – and ant “roads” – especially after heavy rains. 

Serena Fukushima is the public relations and education specialist for the Maui Invasive Species Committee. She holds a bachelor’s degree in environmental studies and a graduate degree in education from the University of Hawaii at Manoa. “Kia’i Moku, Guarding the Island” is written by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that threaten our islands’ environment, economy and quality of life.

This article was originally published in the Maui News on October 8, 2022 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles

Hawaiʻi is home to plant and animal species found nowhere else. For millions of years, new arrivals would establish in our islands an average of once every three thousand years via makani (wind), moana (deep ocean currents), or manu (birds or seeds hitchhiking in their gut). After they arrived to our isolated island chain, they evolved to live in their new environment, becoming new species over hundreds of thousands of years. Today, due to globalization, a new plant, animal, or pathogen that has never been documented in Hawaii arrives every three days. Some of these new arrivals can become invasive, harming not only our environment and Hawaiʻi’s unique biodiversity but also causing adverse effects on our agriculture industry, health, cultural practices, and quality of life.

Multiple agencies across the state work every day to address invasive species issues and local businesses are pitching in. Since many new species arrive hitchhiking on nursery materials, nurseries can be front-line heroes in helping to stop new pests before they spread into the environment.

A new training for nurseries is now available. The Pest Prevention Training Program was created by a grant from the United States Department of Agriculture Animal and Plant Health Inspection Service. The training, offered by the island-based Invasive Species Committees, will feature information about the identification, reporting, and best management practices for some high-risk pests that are either not known to occur in Hawaii, not known to occur in the United States, or pests that are present but are a high priority for containment (like coconut rhinoceros beetle)

Here are some pests not yet found on Maui to be on the lookout for. If you think you’ve seen these pests, report immediately to 643pest.org:

Coconut Rhinoceros Beetle
Currently only found on Oahu, the coconut rhinoceros beetle (CRB). Adults are long (up to two inches), shiny black in color, with a single horn. CRB are nocturnal and can fly. They are primarily found in decomposing green waste or in the crown of palms, where they leave oval-shaped boreholes midrib of fronds or in the crown or trunk of the tree. Fronds cut in a V-shape pattern are another indication of CRB presence. They have also been found in hala trees in Hawaiʻi and can threaten rare native Hawaiian palm species. Extensive damage can kill trees.

Citrus Greening
Citrus greening is bacteria that affect citrus’s vascular system and nutrient uptake. Though not detected in Hawaiʻi, the primary vector, the Asian citrus psyllid, is present in our islands. Throughout the world, the arrival of the Asian citrus psyllid has been followed by the detection of this disease-causing bacteria. This bacterium is responsible for the loss of millions of acres of citrus in the US and beyond. In Florida, citrus greening resulted in 8,000 lost jobs with an economic impact of $4.5 billion. Today, Florida’s citrus industry covers half the acreage it once did. Symptoms include lopsided, bitter, hard fruit with tiny, dark seeds, blotchy mottling on leaves, and fruit that remains green even when ripe.

Red Imported Fire Ant
The Red Imported Fire Ant (RIFA) is an aggressive ground-dwelling ant known for its painful stings. RIFA has resulted in a $1 billion impact in the United States alone. Native to South America, it is a serious pest across the continental U.S. but has not yet been detected in Hawaiʻi. Similar in size and behavior to the well-established tropical fire ant, members of the public are encouraged to submit samples of any stinging ant to their local invasive species committee to prevent an unknown infestation of RIFA from becoming established. Request a free ant collection kit at stoptheant.org.

Lethal Palm Yellowing
Lethal palm yellowing is caused by a bacterial parasite that lives within the plant’s vascular system. This disease affects at least 37 palm species and is responsible for wiping out the majority of the tall-type coconut cultivars in Jamaica and Florida. It can take three to nine months before symptoms are apparent, including yellowing of the leaves and premature dropping of fruit.

Local nurseries can learn more about the Pest Prevention Training as well as the full list of pests to be on the lookout for at plantpono.org/pest-training.

Serena Fukushima is the public relations and education specialist for the Maui Invasive Species Committee. She holds a bachelor’s degree in environmental studies and a graduate degree in education from the University of Hawaii at Manoa. “Kia’i Moku, Guarding the Island” is written by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that threaten our islands’ environment, economy and quality of life.

This article was originally published in the Maui News on September 10, 2022 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles

One of the rarest birds in the world may soon fly through the remote, forested slopes of Maui. The ʻalalā, or Hawaiian Crow, is endemic to our islands, but due to impacts from introduced predators (such as cats and mongooses), loss of habitat, and diseases, they are now extinct in the wild. Just over 100 individuals are all that remain in the world, raised in conservation breeding facilities on Hawaiʻi Island and Maui. The latest efforts to reintroduce birds to the wild on Hawaiʻi Island took place between 2016-2019. The birds suffered low survival rates after release, which led scientists to pause the program. On Hawaiʻi Island, ʻalalā has a native predator- the ʻio, or Hawaiian hawk. There are no breeding populations of ʻio on Maui, so conservationists believe that the Valley Isle could serve as the next step in the recovery of the endangered Hawaiian crow.

The Hawaiian Islands were home to at least five different native crow species. ʻAlalā (Corvus hawaiiensis) are the only ones that remain, and the last wild individuals were observed by researchers on Hawaiʻi Island in 2002. Subfossil records indicate that at least one variety of these Hawaiian crows was present on Maui, Molokaʻi, and Oʻahu.

Sarah Malick-Wahls is the Maui Nui ʻAlalā Research and Recovery Coordinator with the Maui Forest Bird Recovery Project. Her team is looking at remote, native forested areas on Maui to release captive-bred birds. She explains, “ʻAlalā thrive in ohia dominant forests, and multiple Maui sites have the potential to host this endangered species once again.”

ʻAlalā have a varied diet- they eat invertebrates, eggs, and nestlings of other forest birds, nectar, and carrion- but their diet of native fruits made them an integral part of a native forest ecosystem as seed dispersers. Indulging in over 30 varieties of native fruiting plants, ʻalalā could contribute to restoring diverse native forests that benefit the watersheds, cultural practices, and unique plants and animals that inform Hawaiian culture. Intelligent and vocal, alala form complex social relationships with human-like calls. One translation of ʻalalā means to “bawl, caw, wail, scream, etc.” which perfectly describes the sound of their cacophonous symphony. 

Reintroduction efforts to bring back the call of ʻalalā to Hawaii Island forests have been complicated. Introduced predators such as mongooses, rats, and cats have greatly impacted ʻalalā survival, especially fledglings that spend time on the ground while learning to fly. Some crows have even contracted toxoplasmosis transmitted from feral cats, which is still a concern for future release efforts.  While Hawaiʻi Island reintroduction efforts are on pause, conservation breeding facilities are running out of space to house the entire population of ʻalalā, so conservationists are thinking creatively about reintroducing Hawaiian crows to their former homes on other islands. Multiple ʻalalā populations in separate locations also help ensure the species’ survival in the event of extreme weather instances (like hurricanes) or other unforeseen circumstances that could threaten this critically endangered species.

“The reintroduction of ʻalalā to Maui could contribute not only to the survival of this species but can help revitalize and restore native forests.” Malick-Wahls explains. Along with her team, she’s held meetings with communities in East Maui–one of the potential release areas–to share the proposed plans. “So far, community input has been overwhelmingly positive.”Malick-Wahls says.

Her team will incorporate comments from the initial community meetings into a release plan for draft environmental and cultural assessments. These drafts are projected to be ready this winter for broader public commenting. If all goes well, the forests of Maui may once again be filled with the distinctive call of this treasured native species in its forests after hundreds of years of silence.

Serena Fukushima is the public relations and education specialist for the Maui Invasive Species Committee. She holds a bachelor’s degree in environmental studies and a graduate degree in education from the University of Hawaii at Manoa. “Kia’i Moku, Guarding the Island” is written by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that threaten our islands’ environment, economy and quality of life.

This article was originally published in the Maui News on August 13, 2022 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles

In June of 2022, the Hawaiʻi Department of Agriculture (HDOA) alerted the public that tissues submitted by a practicing Maui Veterinarian tested positive for Rabbit Hemorrhagic Disease.  The owner had a farm in Kula, and HDOA determined that nine of the twelve of their rabbits had died fairly suddenly without showing significant prior signs of illness. Only recently found in the United States, RHDV2 is a virus found in hares and rabbits that causes internal bleeding and death. The Maui detection marked the first known case of this disease in Hawaii.

A New Mexico-based wildlife biologist encountered wild rabbit carcasses in 2018 while walking his dog in the desert. He sent samples the U.S. Department of Agriculture confirmed as the country’s first case of rabbit hemorrhagic disease (RHDV2). The virus later caused outbreaks in 2020 for both wild and domesticated rabbits throughout 19 states. In response, HDOA ramped up biosecurity efforts to prevent infected rabbits from arriving to our islands.

Dr. Jason Moniz is the Veterinarian Program Manager with HDOA’s Animal Industry Division, Animal Disease Control Branch. “Since the 2020 outbreak of RHDV2, importers of rabbits are required to have a veterinarian examine and issue a Certificate of Veterinary Inspection within 72 hours before departure to ensure that they are healthy and have not been exposed to RHDV2. ” Upon arrival in Hawaii, inspectors check the animal again before releasing it to the owner. Finally, owners are required to quarantine the rabbit for 30-days before introducing it to other rabbits. Inspectors do follow-up calls with imports seven days after arrival to ensure the rabbits remain healthy. This strict process also provides HDOA with records on 100% of the rabbits that come into Hawaii. If there is a disease outbreak, they have the records to trace the potential origin.

With this recent case, HDOA couldn’t find a link between any introduced rabbits and those on the Kula farm. “It’s like this dropped out of the sky,” Dr. Moniz stated. However, he has suspicions about how the virus may have arrived. “RHDV2 is an incredibly hardy virus, able to survive not only on rabbits, people, and inanimate objects for up to three months.” he explains. Even wearing an unwashed piece of clothing after coming in contact with sick rabbits could trigger an outbreak months later if it comes into contact with healthy ones.  Dr. Moniz also has concerns about the potential for feed to be contaminated if harvested from areas where RHDV2 is present.

Good sanitation and biosecurity practices are essential for protecting rabbits, and the same general practices apply when introducing any new animal (or plant) to protect Hawaii from new invasive pests. HDOA recommends the following:

1. Keep new rabbits and other animals separated for at least 30 days. Dogs, cats and other imported animals are not at risk for RHVD2, but the virus can hitchhike on their fur and spread to healthy rabbits.
2. Sanitize all equipment and cages used for rabbits with 10% bleach or 10% sodium hydroxide mixed with water.
3. Do not allow visitors in rabbitries or let them handle pet rabbits without clean, protective clothing. If a visitor was recently in a state that has an outbreak of RHVD2, ensure they decontaminate any items they traveled with before coming into contact with your rabbit.
4. Always wash hands with warm soapy water before and after entering your rabbit area.

There are currently no wild rabbit populations in the state. If there were, a disease like RHDV2 would be impossible to eradicate. Additionally, wild rabbits can cause environmental damage. In the early 1900s, wild rabbits on Kauo (Laysan) island ate all the vegetation, causing the extinction of native seabirds that lost their habitat. Hawaii state law requires pet owners to contain their rabbits above ground under penalty of fines, loss of the pet, or even imprisonment. Rabbits, well, breed like rabbits; spay or neuter them in case of accidental escape.

Owners or veterinarians experiencing unusual losses of rabbits should contact the HDOA’s Animal Industry Division at (808) 483-7100 or (808) 837-8092.

Report rabbits in wild areas to MISC at (808) 573-6472.

Learn more about rabbit hemorrhagic disease here: https://www.aphis.usda.gov/publications/animal_health/fs-rhdv2.pdf

Serena Fukushima is the public relations and education specialist for the Maui Invasive Species Committee. She holds a bachelor’s degree in environmental studies and a graduate degree in education from the University of Hawaii at Manoa. “Kia’i Moku, Guarding the Island” is written by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that threaten our islands’ environment, economy and quality of life.

This article was originally published in the Maui News on July 9, 2022 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles