invasive species — Maui Invasive Species Committee (MISC)

Two-lined spittlebug: A threat to Hawaiʻi’s ranches, watersheds

Posted on March 23, 2021 by Serena Fukushima

In 2016, a rancher on Hawaiʻi Island saw a large swath of his green pastures quickly turn brown. Surveys revealed a new invasive pest and even more damage: the two-lined spittlebug (Prosapia bicincta) had already decimated 2,000 acres of his land in the Kona area. Over the last four years, the infestation has expanded across 175,000 acres of rangeland – an area nearly half the size of Oʻahu.

At this rate, the voracious bug is consuming 35,000 acres of pasture land each year. Maui ranchers are worried that the two-lined spittlebug will make it to our island and damage pastures here.

Adult two-lined spittle bugs are aptly names for the two bright orange lines on the adultʻs black wings. These tiny pests are causing a huge impact on Hawaiʻi Island ranchlands, consuming 35,000 acres of pastureland each year.

Native to the Eastern United States, the two-lined spittlebug is a recognized pest of pastures and turfgrass in North America and elsewhere in the world. Aptly named for the two bright orange lines on the adult’s black wings, the “spittle” part comes from the white frothy mass that young nymphs make by blowing bubbles out of their abdomen, creating a camouflage defense from predators. Mature two-lined spittlebugs have a deep red head, abdomen, and legs. Nearly a half-inch long, they are highly active, able to jump almost three inches high. The crop damage comes from the bug’s feeding habits. Spittlebugs are sap suckers – feeding primarily on grasses. The saliva of adults contains an enzyme that interferes with photosynthesis and can even kill grasses at the root.

Kikuyu is the dominant pasture grass in the state; about 70% of livestock production relies on this protein-rich food source. Even if this invader doesn’t kill the grass, it can reduce the overall nutritional value and palatability of kikuyu. Kikuyu grass benefits more than just cattle, helping to curb erosion of our watersheds and reduce coastal runoff. Jordan Jokiel, Vice President and Land Manager of Haleakalā Ranch says, “Even though it is not native, kikuyu is a great ally to conservation efforts and key in land stewardship. From grazing, to silviculture, to native reforestation efforts, kikuyu keeps down ecosystem altering weeds, not only in pastures but remnant native forests as well.” When kikuyu and other pasture grasses are weakened or reduced, invasive and cattle-toxic weeds such as blackberry, gorse, crofton weed, and fireweed can move in.

The saliva of the two-lined spittlebug contains an enzyme that kills grasses at the root. Since its discovery in 2016, it has destroyed more than 175,000 acres of rangeland on Hawaii island. When pasture grasses are weakened or reduced, invasive weeds can move in. — CTAHR photo

The crippling effects the two-lined spittlebug could have on the state’s $45 million-a-year cattle industry is a significant impact. It would also hinder efforts to increase food security by raising more meat locally. Although not yet on Maui, the fast-paced movement of this pest poses a serious threat. William Jacintho, a fourth-generation rancher and President of the Maui Cattlemen’s Association, says,

The potential impact of the spittlebug on Maui would be huge. With the rate of how it spreads, we’re like sitting targets, not knowing if or when it will hit.”

Prevention and early detection activities are key to stopping this pest from reaching Maui or finding it early when it can still be controlled. To help stop its spread on Hawaiʻi Island and prevent it from becoming established on other islands, the Natural Resources Conservation Service, Big Island Invasive Species Committee, Hawaiʻi Cattlemen’s Council, and the University of Hawaiʻi Extension Service established a working group for research and outreach. Franny Brewer, Big Island Invasive Species Committee Public Relations Specialist, urges the public, “Monitor your lawns and pasture areas and report large patches of dead grass that can’t be explained by environmental factors.” Brewer also encourages people to learn what the two-lined spittlebug looks like. “If you see one, trap it, and report it to 643-PEST immediately.” Jacintho also emphasizes good cleaning protocols to prevent inadvertent spread of the bug. “If you are in any pasture, make sure you clean your boots, equipment, and check your cars and bags. If you don’t have a reason to visit a pasture known to have the spittlebug, don’t go.”

The two-lined spittlebug is a new invasive pest threatening Hawaii’s pasture lands and cattle industry. The top image displays the prominent bright orange lines on the adults’ wings, while the bottom is a spittle mass formed by juvenile bugs for camouflage. If you find a two-lined spittlebug, trap it and call 643-PEST immediately. — CTAHR photo

Many new invasive pest species are reported by the public. We rely on the eyes and ears of our community to ensure the protection of our island home. For more information about this pest, visit: https://globalrangelands.org/state/hawaii

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 January 9, 2021 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Don’t Let Hawaii Get Skunked: Preventing A Smelly Invader

Posted on March 23, 2021 by Serena Fukushima

Hawaiʻi is the only state in the U.S. that is rabies-free. State law requires that dogs, cats and carnivores complete a quarantine before entering our islands to ensure that they don’t bring in this deadly virus. However, the process of keeping our rabies-free status has started to get a little smelly with the appearance of several recent hitchhikers.

Over the last three years, Hawaiʻi Department of Agriculture (HDOA) Plant Quarantine Branch (PQB) Inspectors successfully captured four skunks near the harbors and airports in Honolulu and Kahului. And citizens have reported other sightings: In May 2020, someone submitted a video to a social media site showing a skunk in Polipoli. At the end of January of this year, a skunk was filmed near the Costco Maui gas station. In both instances, HDOA PQB Inspectors immediately searched the surrounding areas, deployed traps, and conducted outreach to businesses and the general public, but have not caught anything to date.

Using a can of tuna and a cat trap from the Maui Humane Society, workers captured a skunk that was spotted at Kahului Harbor in Decembe 2020r. — The Maui News / MATTHEW THAYER photo

There are no skunks in Hawaiʻi, outside what’s permitted to live at the zoo. Skunks are among the leading wild carriers of the rabies virus (other significant carriers are bats, raccoons, and foxes). This viral disease is transmitted through an animal’s bite, infecting mammal’s central nervous systems and ultimately causing disease in the brain and death. Vaccinations protect pets and domestic animals in the continental U.S., however, there are still cases of pet and human exposures. Each year in the U.S., hundreds of thousands of animals need to be placed under observation or tested for rabies, and between 30,000 to 60,000 people need to receive rabies post-exposure treatment.
In the continental U.S., skunks live in diverse desert, forest, and mountain ecosystems. They prefer open spaces to forage and are primarily nocturnal. Skunks are typically the size of a cat, and are famous for their foul-smelling defense mechanism to deter predators: well-developed scent glands and coordinated muscle control let them accurately aim their spray up to six feet away.

Although it is unknown how skunks snuck into Hawaiʻi, Fern Duvall, Native Ecosystems Protection and Management Maui Nui Program Manager of the Department of Land and Natural Resources Division of Forestry and Wildlife, suspects that it’s all about location. “Since skunks prefer open spaces, they could be foraging around loading areas near shipping containers”, Duvall explains, “Since they’re nocturnal, they could seek shelter in a dark container and when the sun starts to rise, accidentally get locked in.” Duvall also mentions the danger of proximity of Maui feral cat colonies to points of entry if skunks were to get loose,

“Skunks could seek food at feral cat feeding stations nearby the harbor and Kanahā Wildlife Refuge. If a rabid skunk were to bite a feral cat, it would spread quickly, creating a serious health crisis for pets and humans alike.”

A rabid skunk could impact native wildlife as well. Hawaiʻi’s only two native land mammals are the Hawaiian Hoary Bat and Hawaiian Monk Seal. Since all mammals are susceptible to the rabies virus, this deadly disease can be transmitted to these species by a rabid animal. Even if not carrying the rabies virus, skunks could eat the eggs and chicks of ground-nesting native birds, some of which are endangered and found nowhere else in the world.

Officials continue to rely on the public to be the eyes and ears of our communities to report unusual animals such as skunks. Maui HDOA Master Journeyman Inspector, Marshall Loope, encourages the public to immediately report any skunk sightings. “If you think you see a skunk, please note an exact, detailed location of where you saw it. If it left any tracks in dirt or sand, take photos of that as well.” Loope cautions the public not to approach a skunk if sighted, “HDOA officials have extensive training and wear personal protective equipment when trapping or encountering any wild animal. If you see a skunk, do not approach or try to capture it. Instead, take a photo or video from a safe distance and report immediately.” If you see a skunk, or any unusual new pest, please report it to the Maui HDOA office by calling (808) 872-3848, going online to www.643pest.org, or calling (808) 643-PEST (7378).

This article was originally published in the Maui News on March 13, 2021 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Yellow-faced bees defenseless and vulnerable to predatory ants

Posted on August 11, 2020 by Lissa Strohecker

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 July 9th, 2017, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Mullein and Milk Thistle-Some Medicinal Plants are a Bad Prescription for the Environment

Posted on May 29, 2013 by Lissa Strohecker Leave a Comment

Humans have always relied on plants for medicine and many modern remedies are still derived from plants.

Blessed milk thistle, or Silybum marianum, isn’t so holy when it forms prickly, invasive thickets. Conservationists quick to eradicate it from Maui pastures. Photo courtesy of Maui Invasive Species Committee

The active ingredient in aspirin, salicylic acid, is now synthesized in a lab but used to be obtained from the bark of willows, or plants in the genus Salix. Digitalis, a drug for heart conditions, is one of a group of medicines extracted from the foxglove plant, Digitalis purpurea. An Alzheimer’s treatment, galantamine, is either produced in the lab or extracted from daffodils. Present-day herbalists harvest or grow plants to treat everything from acne to weight loss.

But while they may have health benefits for people, some medicinal plants may sicken our environment. Mullein, notable for its use as a respiratory aid and a remedy for skin problems, is one example. Common mullein, or Verbascum thapsus, thrives on bare soil at mid to high elevations—think the painted landscape of Haleakalā crater. It can monopolize the habitat of native plants, such as the iconic silversword. Mullein is not established on Maui, but the cinder slopes of Mauna Kea and Mauna Loa on Hawai‘i Island are now covered with this highly invasive plant.

Blessed milk thistle, or Silybum marianum, is renowned to herbalists for protecting the liver from poisons. This thorny thistle is equally famous for its invasiveness. Darwin commented on the impacts of this European native as he rode through the pastures of Argentina: “When the thistles are full-grown, the great beds are impenetrable…” He continued to describe the murderous robbers who hid amongst the thistles. Blessed milk thistle has been found in a Makawao pasture, and is on track for removal. At one time this plant was in cultivation on Maui for its medicinal properties. Fortunately that is no longer the case.

Mullein, or Verbascum thapsus, invades on the open slopes of Mauna Loa and Mauna Kea. This medicinal plant is not a good prescription for the environment. Photo by Forest and Kim Starr.

There is much to be learned from studying plants. The practices of herbalism in naturopathy, traditional Chinese medicine, or lā‘au lapa‘au, Hawaiian plant medicine, all stem from living close to nature. Knowing when to harvest plants and what parts to use is an impressive skill. So too is knowing which plants to grow and where.

Hawai‘i is home to a diversity of plants and animals found nowhere else in the world, some with healing properties. When non-native, invasive species become established, they disrupt the interdependent relationships that characterize healthy, intact native ecosystems. Growing medicinal plants can be a way to revive and retain ancient types of knowledge. It can be an avenue to connect with your natural surroundings. And, with a little forethought, it can be done in balance with the environment.

If you are going to grow your own medicinal plants, choose species that are not invasive or otherwise harmful. The common artichoke, for example, has the same liver-supporting compounds as blessed milk thistle, without the invasive characteristics.

How can you determine whether a plant is problematic? The Hawai‘i Pacific Weed Risk Assessment is a screening tool that evaluates plant species’ biological characteristics and their potential for becoming invasive. Check it out at www.plantpono.org.

By Lissa Fox Strohecker. Originally published in the Maui News, May 12th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Help Hawai‘i–harvest a Christmas tree

Posted on December 13, 2011 by Lissa Strohecker Leave a Comment

‘Tis the season, and tradition calls for pine trees to decorate Maui residents’ homes, although there are many palms decorated in Christmas lights as well. Most Christmas trees are shipped in, but there’s a history of growing pines in Hawai‘i. Ralph Hosmer, Hawai‘i’s first forester, came on the job in 1904. At the time, forests throughout Hawai‘i were in a sorry state. Since Polynesian times, people have greatly altered lowland forests, initially for settlement and taro cultivation, then for sugar cane and pastureland. Feral pigs, goats and cattle escaped into intact forests, trampling shallow-rooted plants and browsing slow-growing plants. Honolulu, prospering from the sugar boom, was exceeding existing water supplies by the 1870s. Recognizing the need to protect and restore vital watersheds, everyone from sugar cane barons to King Kalākaua began fencing out animals and planting trees, some of which were pines.

Mexican weeping pine (Pinus patula) creeps into the native forest of the Waikamoi preserve. Forrest and Kim Starr photo

Hosmer helped turn sentiments about forest protection into cohesive action. He established the first forest reserves in Hawai‘i, beginning in 1906 when Alexander & Baldwin ceded management of acreage on Maui to the territorial government. With newly acquired land, Hosmer accelerated efforts to fence out cattle and goats and planted fast-growing hardy trees. The goals were three-fold: to stop erosion, restore the watershed and provide for Hawai‘i’s timber needs. Hosmer’s experimental plantation high on the slopes of Haleakalā now bears his name, “Hosmer’s Grove.” He planted species familiar from his Mainland forestry background: redwood, ash and pines. For years to come, foresters continued planting non-native species. These trees did prevent erosion on overgrazed lands, but some escaped cultivation to invade nearby ecosystems and crowd out native species.

Three species – Monterey pine (Pinus radiata), Mexican weeping pine (Pinus patula) and maritime pine (Pinus pinaster) – are particularly invasive. They persistently threaten Haleakalā National Park and The Nature Conservancy’s Waikamoi Preserve, transforming native stands into pine forests. Pines grow fast, up to one foot per year and reach maturity quickly, producing seeds within six to eight years. A massive amount of tiny seeds spread easily on the wind, help these pines colonize new areas. Removing pines has proven essential to maintaining the shrub-land and alpine habitat of Haleakalā.

Over the years, crews at Haleakalā National Park have stopped a veritable woodland of pines. Bill Haus and the crew he works with have removed 87,920 pines from the park and surrounding areas since 1982. According to Natural Resource Program Manager Steve Anderson, “Without control, the slopes of the subalpine shrub land would be a pine forest.” Subalpine shrub land is critical habitat for a native plants and animals; conversion to a pine forest would turn this rare Hawaiian ecosystem into a biological desert – no native plants like māmane, pūkiawe, ‘ōhelo or ‘a‘ali‘i; no native birds like the ‘i‘iwi and ‘amakihi.

Monteray pine (Pinus radiata) growing inside Haleakalā crater alongside silverswords. There have been a flush of pine seedlings inside the crater in the last few years. Forrest and Kim Starr photo.

Pines threaten the crater as well. Haus and his crew have removed more than 1,500 pines from inside the crater, with a peak of 778 in 2010.

Anderson said: “I wouldn’t have thought it was possible (for the crater to become a pine forest) several years ago, but it’s clear that potential exists now.”

The recent flush of pine could be the result of the 2007 Polipoli fire. Pines, including those invading Haleakalā Crater, are serotinous, meaning certain pine cones are coated with a waxy substance. These cones stay closed until the heat of a fire melts the coating to release seeds. As an ecological adaptation, it helps pines take advantage of the ash-fertile conditions following a fire. But in Hawai‘i, this adaptation may offer a unique seed-scattering advantage. The Polipoli fire possibly spurred a huge seed release and associated winds carried the seeds into the crater. Pine seedlings are even growing alongside silverswords.

You can help protect the crater from pines, and take home a pine tree! Several organizations will be working with volunteers to remove pines in time for the holidays. Friends of Haleakalā National Park leads efforts to remove pine trees from the crater. Check out their website at fhnp.org for more information.

The Nature Conservancy will be working below Hosmer’s Grove on Dec. 17. Call or email Pat Bily at 856-7665 or pbily@tnc.org for details and to confirm attendance. Both trips are free and open to the public. Dress for wintery weather and bring rain gear, water, tools and rope to bring home your tree or wreath making supplies. Participants also may bring food. Eggnog is optional.

By Lissa Fox Strohecker
Originally published in the Maui News, December 11, 2011 as part of the Kia‘i Moku Column. Check out all of the MISC articles in the Kia`i Moku series at: www.hear.org/misc/mauinews/

Pampas Gone Wild-Haipua‘ena Part 2

Posted on November 21, 2011 by Lissa Strohecker Leave a Comment

Here’s a young, but mature, pampas grass in a mostly native rainforest…pulling this guy up will leave a big hole in the groundcover, a hole means a foothold for another invasive species, in many ways doing more harm than good.

But if we leave the plant alone we’ll continue to loose our watershed and native species to this high-threat invasive plant. How can we remove it? Keep reading…

1. Remove the seed-heads.

2. Tie the pampas in a knot. this is what we refer to as the “ponytail” method; bringing all the pampas leaves together makes it easier to treat and marks the plant as one we’ve treated.

3. Bury the seed-heads deep within the plant. This keeps the seeds from dispersing on the wind, likely how this plant arrived here in the first place.

4. With the seed-heads tucked away and the plant tied together crews can apply a low-concentration herbicide directly to the plant (another benefit of the ponytail method-no over-spray). Within a month the plant will be dead and beginning to decompose and native vegetation will be intact and poised to reclaim this patch of invaded rainforest. The location of each plant we control is recorded with a GPS so it can be monitored in the future to ensure no seedlings have germinated.

There you have it-how to control invasive pampas grass a native rainforest on Maui.

Stay posted to learn how to spot a pampas grass.

The sun sets on another day of field work in the remote rainforest of East Maui

Two-lined spittlebug: A threat to Hawaiʻi’s ranches, watersheds

Don’t Let Hawaii Get Skunked: Preventing A Smelly Invader

Yellow-faced bees defenseless and vulnerable to predatory ants

Mullein and Milk Thistle-Some Medicinal Plants are a Bad Prescription for the Environment

Help Hawai‘i–harvest a Christmas tree

Pampas Gone Wild-Haipua‘ena Part 2

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