Hawaiian Hoary Bat-Our Only Native Land Mammal

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Opeapea is a subspecies of the North American hoary bat and is the only terrestrial mammal native to the Hawaiian Islands.

Under the cover of night a skilled hunter twists and turns in the Hawaiian sky, darting and dodging trees with acrobatic skill to catch dinner.  Little is known about this hunter: scientists don’t have an estimate of its population size, and outside of the scientific community, few people even realize that Native Hawaiian bats exist.

Prior to the arrival of humans, other species traveled to Hawai‘i one of three ways: on the wind, via water, or by wing (either flying here themselves or being carried by a winged creature). It follows that the only native land mammal would bear wings.

‘Ōpe‘ape‘a is a subspecies of the North American hoary bat. Found only in Hawai‘i , it’s listed as a federally endangered species. Its Hawaiian name means “half-leaf,” and refers to the bat’s open wing, which resembles the bottom half of a taro leaf.

‘Ōpe‘ape‘a are more common than most people realize, but researchers have only recently begun to study this species more closely. Genetic evidence indicates that bats colonized the Hawaiian Islands in the not-too-distant past—first arriving approximately 10,000 years ago with a second colonization as late as 800 years ago.

An opeapea, sleeps hanging from a tree branch. Little is known about the Hawaiian hoary bat in part because of their tendency to roost alone in trees. Photo courtesy of Forest and Kim Starr

An opeapea, sleeps hanging from a tree branch. Little is known about the Hawaiian hoary bat in part because of their tendency to roost alone in trees. Photo courtesy of Forest and Kim Starr

Like all bats, ‘ōpe‘ape‘a are nocturnal but you won’t find them roosting in caves. These bats are solitary tree roosters, attaching themselves to the tips of branches on a tall tree.  Weighing in at only ½ oz, these little acrobats are hard to find and even harder to study. Mist nets, the kind used to catch and study songbirds, are not very effective when catching bats, as the tiny mammal quickly learns to avoid the net.

The most effective way to detect ‘ōpe‘ape‘a is with ultrasonic bat detectors that pick up the bats’ vocalizations as they travel and hunt. Recent improvements in ultrasonic detection technology have made bats easier to study, and researchers in Hawai‘i  are working to find out more about these mysterious mammals.

On Hawai‘i Island, researchers detected ‘ōpe‘ape‘a more frequently during the summer at lower elevations, possibly because food is abundant during the summer at lower elevations or because the warmer temperatures mean less stress for newborns and lactating mothers. Mother ‘ōpe‘ape‘a  give birth to pups, typically one set of twins, in May or June and stay with the pups until they are 6-7 weeks old. When the pups are young, the mother will carry them with her on her nightly hunts. When they are old enough to hold on to the roosting site themselves, she will leave them safe in the tree until they are old enough to fly with her and learn to hunt. ‘Ōpe‘ape‘a’s diet is mostly moths, but includes mosquitoes, beetles, crickets, and termites.

When temperatures began to cool, researchers on Hawai‘i  Island found increased bat activity at higher elevations. Whether that means they “migrate” up and down the mountain is still uncertain. Even movement between islands is unknown, but bats are on all the main Hawaiian Islands so inter-island movement occurred at some time in the past.

Researchers studying the opeapea are learning  more about this federally endangered species. It has been seen throughout Maui, from sea level to the top of Haleakala as it swoops through the sky. Photo by Forest and Kim Starr

Researchers studying the opeapea are learning more about this federally endangered species. It has been seen throughout Maui, from sea level to the top of Haleakala as it swoops through the sky. Photo by Forest and Kim Starr

On Maui, researchers know ‘ōpe‘ape‘a are in Haleakalā National Park, both at the summit and in the crater. The flying insectivores are often spotted at sea level as well. There is a good chance they are in your neighborhood.

Look for bats at twilight, particularly along pasture edges pastures and clearings. Bats dart back and forth as they catch insects, whereas the rare birds returning to roost take a direct path.

The threats to ‘ōpe‘ape‘a not yet clear but one cause of death is collisions with man-made objects such as communication towers, wind turbines, and barbed wire. This may happen as the bats catch an insect and “turn off” their echolocation for a few seconds to eat.

You can help protect this endangered species. If you know you have ‘ōpe‘ape‘a in your area, protect roosting sites–don’t cut tall trees until after the summer pupping season.  If you are installing a fence in a pasture, consider using barbless wire on the top strand to prevent snagging a hunting bat. If you find a dead bat on Maui, contact Fern Duvall, Wildlife Biologist with the Department of Land and Natural Resources, at 873-3502. You can help scientists learn more about the genetics and habits of this cryptic creature—far more spectacular than spooky.

By Lissa Fox Strohecker. Originally published in the Maui News, October 12th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committe

Pacific Cooperative Studies Unit: the fingers on the keyboards that get the boots on the ground

Crew  with the West Maui Mountains Watershed Partnership build fence in some of the most difficult terrain imagnable. This and other resource managment efforts are possible thanks to the work behind the scnese at the Pacific Cooperative Studies Unit. Photo by Chris Brosius

Crew with the West Maui Mountains Watershed Partnership build fence in some of the most difficult terrain imagnable. This and other resource managment efforts are possible thanks to the work behind the scnese at the Pacific Cooperative Studies Unit. Photo by Chris Brosius

On any given day, there are hundreds of people at work throughout Hawaii to protect the āina.

Fence crews pound ungulate-proof fences into place in thickly forested terrain, spending weeks away from their families. Botanists scale cliff faces, tracking down the last populations of rare and endangered plants. A researcher on Hawai‘i Island loads gallons of peanut butter into a ceiling spackler testing new ways to control little fire ants in trees.

These people all have one thing in common: the Pacific Cooperative Studies Unit, based out of the Botany Department at the University of Hawai‘i at Mānoa. The unit’s staff works behind the scenes, helping project managers buy helicopter time, hire staff and pool funds from different sources so that conservation crews can stay in the field and focused on their work.

The Pacific Cooperative Studies Unit began 40 years ago when the University of Hawai‘i was providing scientific services to the state’s national parks.

Today, the unit facilitates funding for many of the “boots on the ground” projects throughout the state. It enables multiple funders and agencies to work together. In Maui County, the unit administers three watershed partnerships, two bird projects, one seabird project and two invasive species committees. Each of these projects has field staff, baseyards or offices, vehicles and equipment to maintain, safety concerns and multiple funding sources.

They work on land that falls under various types of management, from private to public and county to federal. A project might have funds from 10 different sources in one year, each with different deadlines and contract requirements. Having a single organization to pool and manage these resources allows the project to remain effective.

Despite supporting 350 staff across five islands and an annual budget of approximately $12 million per year, the unit is a surprisingly low-key organization, an approach mirrored in the philosophy of Unit leader David Duffy, a professor of botany with UH- Mānoa.

“We’re not top down. We try to give projects as much autonomy as possible,” he said.

So, the unit’s role in protecting natural resources in Hawai‘i may be overlooked.

One of the main benefits the unit offers its projects is flexibility. “We can do things that other people can’t, and we can do them faster,” Duffy said. State and federal organizations can be limited by mandates and jurisdiction, whereas a unit project may work wherever the need is.

Need drives the continued presence of the unit. If invasive species were no longer a threat, or endangered plants were safeguarded across the archipelago, it could go by the wayside. “In the best of worlds, we would go away,” Duffy said. “We continue to exist because we’re useful.”

The unit’s efforts mean that researchers and field crews can get the funding needed to continue monitoring and preserving rare native ecosystems across the āina.

To learn more about PCSU and the projects it manages, visit manoa.Hawai‘i .edu/hpicesu/pcsu.htm.

By Lissa Fox Strohecker. Originally published in the Maui News, September 14th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committe

Coqui calls on the rise

A male coqui guards a clutch of eggs inside a pipe. With coqui populations on the rise throughtout the state there is an increased likelihood of coqui inadvertently reaching Maui. MISC file photo

A male coqui guards a clutch of eggs inside a pipe. With coqui populations on the rise throughtout the state there is an increased likelihood of coqui inadvertently reaching Maui. MISC file photo

The call of the lone coqui may not be increasing in volume, but calls reporting coquis on Maui are on the rise.

There’s been a dramatic increase in coquis arriving on Maui. In 2013, 25 Maui residents reported the presence of these noisy amphibians, almost double the reports from 2012 and 2011 combined. And the trend seems to be continuing for 2014, with reports of these invaders popping up in surprising places across Maui.

Coqui frogs are known to be in a handful of scattered populations around the island. According to the Maui Invasive Species Committee, all are under control and on target for eradication, with the exception of Māliko Gulch in Ha‘ikū. But the influx of new arrivals has the MISC crew concerned.

“We interview homeowners when there are new frogs reported, but we haven’t found any clear source of introduction,” said MISC Operations Manager Adam Radford. “In general, there are more frogs in the state than there used to be.” As coquis increase in number, particularly on Hawaii Island, so do the chances that the notoriously loud hitchhikers will spread elsewhere.

If you have heard a coqui, you know why they are not a welcome addition to your neighborhood. A single male frog has an 80- to 90-decibel screech, as loud as an alarm clock or freeway traffic. The frogs call from dusk until dawn. Coquis arrived in Hawai‘i sometime before 1988. In the absence of predators or competitors, their numbers ballooned, reaching densities exceeding 36,000 frogs per acre – two to three times greater than in their native range in Puerto Rico.

The coquis’ ear-splitting chorus may be the most obvious impact of this invasive species, but recent research suggests there are secondary, less-apparent consequences to allowing these quarter-sized pests to become established. Researchers have long known that coquis eat invertebrates such as insects, spiders and worms, but they recently discovered how these invasive amphibians skew the ecosystem in Hawai‘i.

What goes in must come out. The coqui frogs’ most significant change to the landscape is through the increased nutrient input from their droppings. While this sounds like a good thing, altering nutrients can create an environment more hospitable to non-native species.

This coqui was discovered by an observant Maui resident, hiding in a potted plant recently purchased from a garden shop. MISC file photo.

This coqui was discovered by an observant Maui resident, hiding in a potted plant recently purchased from a garden shop. MISC file photo.

Researchers found increased leaf production rates in invasive strawberry guava in coqui-invaded sites compared to other sites. Plants native to Hawaii evolved in nutrient-poor conditions, so increased nutrient input favors non-native plants. Additionally, scientists found a greater number of insects in the order Diptera (flies) associated with coqui-invaded areas, the outcome of more excrement and more coqui carcasses.

Unfortunately, the coqui frog is widespread on Hawai‘i Island and cannot be eradicated. There, residents work together to control frogs in individual neighborhoods, and nurseries bathe plants at a hot water treatment facility before shipping stock off island. Barriers around parking lots prevent frogs from moving between cars and the areas surrounding the lot. But in the big picture, these stop-gap measures only will provide a temporary respite. We can prevent this from happening on Maui. With only one significant population in Māliko Gulch, land managers believe that the frogs can be eradicated, and new infestations thwarted.

You can help. Report coqui frogs to the Maui Invasive Species Committee at 573-6472. Support business and landscapers who take steps to prevent the spread of coquis via the plant trade. And, find a list of certified coqui-free businesses at coquifreemaui.org. For more detailed information about recent research on impacts of coqui, check out the coqui frog information page under priority pests at mauiinvasive.org.

By Lissa Fox Strohecker. Originally published in the Maui News, August 10th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee

The Haleakalā silversword—the greatest threat is now climate change

 

The Haleakala silversword is found only in Haleakala crater.

The Haleakala silversword is found only in Haleakala crater.

The Haleakalā silversword is one of Maui’s most spectacular native plants. Known as ‘āhinahina to Hawaiians and Argyroxiphium sandwicense subsp. Macrocephalum to botanists, it is the quintessential plant of Haleakalā Crater and grows nowhere else on Earth. This much-loved species has survived many threats over the last century—but a warming climate may prove its toughest challenge yet.

In the late 1800s, silverswords were so plentiful that explorer and naturalist Isabella Bird wrote of finding “not…one or two, but thousands of silverswords, their cold, frosted silver gleam making the hill-side look like winter or moonlight.” In the decades that followed, feral goats munched silverswords as they roamed the crater and 2-legged souvenir hunters yanked the unusual plants up by their roots. Anecdotal accounts from the 1920s and ‘30s indicate that the silversword population was in dramatic decline.

After Haleakalā National Park fenced the summit and removed the last of the goats, there was good reason to believe that silverswords would recover. Visitors learned to take photos rather than live plants as souvenirs. In 1982, biologists began documenting the recovery of this threatened species that had become part of the Park’s allure.

They counted silverswords at various sites throughout the crater nearly every year, but were surprised by the results. “Data from plots show a really obvious trend when you look at them over the last 30 years,” explains Paul Krushelnycky, a University of Hawai‘i researcher currently studying the silverswords. From the early ‘90s or so you get a steady decline.”

He investigated potential causes of the decline, first looking at invasive species. “Ants were a concern—they could be impacting the pollinators,” says Krushelnycky. “But it doesn’t look like that’s happening right now.” While Krushelnycky fears the invasive Argentine ant could impact silverswords in the future as the insect’s population expands, ants are not currently causing a problem.

When Krushelnycky compared silversword population data to climate data, specifically rainfall during the drier summer months, he saw a clear pattern: as summer rainfall declined, so did the silverswords. Today, the silversword population throughout the crater is only about 40-50 percent of what it once was. “As summers got drier,” says Krushelnycky, “drought stress was an obvious part of the picture.”

According to scientists’ predictions, this trend will continue. Rising temperatures in Hawai‘i affect the inversion layer, possibly causing the ring of clouds that surrounds Haleakalā in the afternoon to become shallower. This cloud layer currently drifts through the crater, providing water via condensation for the silverswords—which have hairs on their leaves specially adapted to collect this moisture. As the height of the inversion layer continues to drop—as it’s predicted to with rising temperatures— clouds drift into the crater floor less frequently.  Consequently, less moisture is available to the silverwords living at the crater floor. Another potential cause of the drying in the crater is an overall increase in the frequency occurrences of the trade-wind inversion. “What we are seeing is consistent with basic predictions of climate change—that plants at lower elevations will have to move up,” says Krushelnycky. But for species in an alpine ecosystem on an isolated island in the Pacific, there’s only so far they can go.

The effects of climate change are frequently talked about in the news in Hawai‘i. Rising sea levels threaten coastal ecosystems and even zoning regulations for coastal buildings. But the rare plants and animals found in the alpine ecosystem in Hawai‘i are extremely vulnerable. These species are uniquely adapted to harsh climates, and sudden changes in their environment will leave them vulnerable.

Krushelnycky is currently looking for genetic variations among plants to see if some populations are more drought tolerant. At the same time, he’s looking to see if elevation factors into silversword survival. His findings will likely influence future decisions about where to collect seeds and where to plant keiki – results that may spell hope for the plant synonymous with Haleakalā.

Learn more about the impacts of climate change on the silversword: http://www.usgs.gov/newsroom/article.asp?ID=3490#.U4jzcnK-2G4

Learn more about Hawai‘i ’s changing climate: www.soest.hawaii.edu/coasts/publications/ClimateBrief_low.pdf.

*The original article, as printed in the Maui News, overstated the decline in silversword population indicating the remaining population is only 25-30% of what it was when monitoring began. While this is correct in certain monitoring plots, the population throughout the crater is 40-50% of what is once was. This correction is reflected above.

By Lissa Fox Strohecker. Originally published in the Maui News, May 11th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee

LFA – Insidious invaders that you can stop

Ginger Johnson bought a hapu‘u fern late in 2013 to plant alongside others in her yard.

MISC employee Molly Wirth surveys for LFA in response to a Maui residents concern about little fire ant moving in hapuu. No LFA were found. MISC file photo

MISC employee Molly Wirth surveys for LFA in response to a Maui residents concern about little fire ant moving in hapuu. No LFA were found. MISC file photo

But when she heard the news in early January that inspectors found a new species of fire ant hitchhiking from the Big Island to Maui in hapu‘u , she thought of the hapu‘u  she had just brought home. What if the ants had infested her yard? “I was very concerned. I went and looked at it and didn’t see anything.” Johnson left the hapu‘u in the shade of a tree, uncertain about what to do.

“I called a friend of mine who happened to be a biologist. He advised that I do the peanut butter and chopstick test.” The simple test, placing a peanut-butter smeared chopstick near material that may carry little fire ant, will attract many ants, including Wasmannia auropunctata, the little fire ant (LFA). Johnson tested but did not find any ants that resembled LFA, which are tiny (as long as a penny is thick) and uniformly light red in color. She was still concerned and called the Maui Invasive Species Committee (MISC) for further assistance.

Crews from MISC arrived, bagged the hapu‘u to contain any ants, and took it to the Hawai‘i Department of Agriculture (HDOA) where entomologists examined it for LFA. No suspect ants were found. But because the hapu‘u had been at Johnson’s house for a little while, MISC workers surveyed her property. They’ll return several times to ensure LFA weren’t introduced. This new pest is so damaging, it’s worth the extra effort to prevent it from becoming established on Maui.

Little fire ants can be hard to find when first introduced. Workers may not be foraging far from the queen, and even if several colonies are present, these miniscule insects are very hard to detect. Bait (like the peanut-butter-smeared chopstick) must be placed every two feet or closer. By the time the ants are stinging people or blinding pets, the population may have been present for months or years.

Little fire ants on the large end of a chopstick. Photo courtesy of the Hawaii Department of Agriculture.

Little fire ants on the large end of a chopstick. Photo courtesy of the Hawaii Department of Agriculture.

These opportunistic ants don’t build mounds; rather they find shelter in leaf litter, under rocks, or in loose tree bark. Little fire ants are insidious invaders. They don’t announce their presence by swarming feet and legs; instead, they sting when they are trapped against skin or in clothing. Establishing nests in trees and amongst ground cover, LFA can reach densities of 20,000 workers per meter, or a whopping 155 ants in a square inch. At that level, painful encounters become unavoidable.

So: if it’s small, call. MISC will survey your property, using peanut butter to attract ants. Alternatively you can submit a sample to MISC. Expert taxonomists review all ants collected. If they suspect little fire ants, they’ll take the sample to HODA for confirmation.

Little fire ants are not known to be established on Maui, Lāna‘i or Moloka‘i; though small infestations have been detected and controlled on Maui and Lāna‘i. Resources exist to stop this pest in its tracks. An interagency team made up of the Hawai‘i Department of Agriculture, Hawai‘i Ant Lab, and Maui Invasive Species Committee will respond to any new infestation in Maui County.

Inspectors at the Kahului airport destroy any little-fire-ant-infested shipments they find, but some might slip through. No organization has the resources to survey all of the places or pathways LFA could travel. If you have brought any soil, potted plants, or vehicles from off-island in the last year, take time to test for LFA. Waiting until you are stung is too late.

“I’m tremendously careful now,” says Johnson. “Someone just told me the other day they got a magnolia tree from the Big Island. My first thought was: how well did you test it?”

To learn more about the little fire ant, including detailed instructions for how to survey, visit the Hawai‘i Ant Lab’s website at littlefireants.com. The HDOA site at  hdoa.hawaii.gov/pi/main/lfainfo/ has updated information on spread. If you suspect you may have LFA, please don’t try to treat them yourself– contact MISC at 573-6472 or the Maui branch of HDOA at 872-2848. “The issue is so frightening,” says Johnson. “I’m born and raised here, so I’ve seen many things change. The only time to deal with something like this is before it’s a disaster.”

By Lissa Fox Strohecker. Originally published in the Maui News, May 11th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

CRB spells trouble for Hawaii’s palms

At over 2.5" in length, the Coconut Rhinoceros Beetle would seem hard to miss, yet it spends most of it's life in the crown of a palm tree. Photo courtesy of Hawaii Department of Agriculture.

At over 2.5″ in length, the Coconut Rhinoceros Beetle would seem hard to miss, yet it spends most of it’s life in the crown of a palm tree. Photo courtesy of Hawaii Department of Agriculture.

At two and a half inches long and sporting large horns on the front of its head, the coconut rhinoceros beetle (CRB) is a remarkable-looking creature, but this lumbering giant of an insect is also a devastating pest of coconut and palm trees. Following its arrival on Palau in 1942, this critter from Southeast Asia quickly spread widely, wiping out 50 percent of the palms in the archipelago.

On December 23, 2013, during a routine survey of the Joint Base Pearl Harbor-Hickam, surveyors discovered the coconut rhinoceros beetle in palms on the base, marking it the first reported case of the insect in Hawai‘i.

Teams mobilized to survey the surrounding area and control the infestation. Based on the size of the population, the beetle may have been present for up to two years.

Populations of the beetle in its home range are kept in check by natural controls (predators, disease, and competition) but globalized shipping has transported the beetle throughout the Pacific; it has become a major palm pest, affecting the Philippines, the Republic of Palau, Fiji, American and Western Samoa, and most recently Guam. It has spread elsewhere in the world, hitching rides in the holds of aircraft, through nursery stock, cargo, mulch and sawdust.

The beetles leave boring holes in the crown of coconut palms. Photo courtesy of HDOA

The beetles leave boring holes in the crown of coconut palms. Photo courtesy of HDOA

When coconut rhinoceros beetle was detected in Guam in 2007, Hawai‘i officials grew concerned that the pest would make its way here, given the regular exchange of goods between the islands; however, it’s not known how the beetle arrived in Hawai‘i, nor where it came from.

Notable as they are in appearance, these beetles spend most of their adult stage out of sight, high in the tops of coconut trees. These monstrous beetles bore into the crowns of healthy palms, biting through unopened leaves and then feed on the sap produced by the injured plant.

Mature coconut trees can typically withstand feeding damage, but young plants under three years old often die. Over time, the mature trees are not replaced.

The population of these giant beetles grows quickly. An adult female beetle lays 70 to 140

As CRB bore through unfurled leaves the leave signs of damage that become apparent as the leaves unfurl.  But  this is not a definitive indication--other damage can leave V-shaped cuts. Photo courtesy of HDOA

As CRB bore through unfurled leaves the leave signs of damage that become apparent as the leaves unfurl. But this is not a definitive indication–other damage can leave V-shaped cuts. Photo courtesy of HDOA

eggs in its lifetime, depositing  the eggs in mulch heaps or soft logs where they hatch into large whitish larvae. Even the larvae reach an impressive size: between 2 3/8 inches to just over 4 inches long. These brown-headed larvae with bluish-grey tail tints feel “squishy” and crawl on their sides. They lack any marking on the underside of their mouth.

Larvae mature through several stages over the next 2 to 3 months and finally form a cocoon where they become adult beetles. The adults hatch out at night, flying a few hundred feet to a nearby tree

While coconuts are the preferred host, the beetles can live on other palms, bananas, sugar cane, agave, even ironwood and taro.

Based on current surveys, the infestation on Oahu seems limited, with all known sites under active control. However, with any flying insect, certainty about the extent of an infestation can be challenging. Coconut rhinoceros beetles have not been detected on Maui. The key to preventing their establishment–and protecting coconuts, native and landscape palms in Hawai‘i–is detecting their presence early. You can help by looking for boring holes in the palm crown and the distinctive V-shaped cut on the leaves. Other types of pests can cause cuts and boring, but if you see these symptoms, an expert can help check it out.

To learn more, visit the Hawai‘i Department of Agriculture CRB update page at http://hdoa.hawaii.gov/pi/main/crb/. Submit pictures of damaged coconuts or palms via the Project Noah website. Look for the mission entitled “Help Save Hawai‘i’s Coconut Trees”- projectnoah.org/missions/18256600. You can also use, the online reporting tool at reportapest.org, or call the Hawai‘i Department of Agriculture’s Pest Hotline at 643-PEST (7378) toll-free from any island.

By Lissa Fox Strohecker. Originally published in the Maui News, April 13th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

What’s that new black caterpillar?

Secusio caterpillar eat fireweed and other invasive plants like Cape ivy, The Hawaii Department of Agriculture estimates it will take 8 caterpillars to kill one fireweed plant. Photo courtesy of HDOA.

Secusio caterpillar eat fireweed and other invasive plants like Cape ivy, The Hawaii Department of Agriculture estimates it will take 8 caterpillars to kill one fireweed plant. Photo courtesy of HDOA.

A new fuzzy black caterpillar is starting to show up across Maui—a promising omen for cattlemen and conservationists alike.  The caterpillar is the larva of the Secusio extensa moth, a biological control for firerweed released by the Hawai‘i Department of Agriculture (HDOA) to control fireweed in March of 2013.

Diana Crow, a horticulturalist with ‘Ulupalakua Ranch, has been helping to raise and release Secusio moths on Maui.  “For a while I wasn’t seeing them at all. Then things changed when the rains came. I started seeing them around lights. That was the first indication they were reproducing in the wild.”

Impacts on fireweed aren’t likely to come immediately.  Established in the islands since at least the 1980s, fireweed now infests an estimated 850,000 acres statewide.  According to Rob Curtiss, an entomologist with HDOA, it takes an average of eight caterpillars to kill one fireweed plant. “What will probably happen is that the population [of Secusio] will continue to grow and reach epidemic proportions, then we will see them start to defoliate fireweed.”

Fireweed, Senecio madagascarensis, is a highly invasive weed, toxic to many animals that blankets pastures on Maui and Big Island. Photo courtesy of Forest and Kim Starr.

Fireweed, Senecio madagascarensis, is a highly invasive weed, toxic to many animals that blankets pastures on Maui and Big Island. Photo courtesy of Forest and Kim Starr.

Secusio may be getting some help from another unwelcome pasture pest; the caterpillars are capable of living off Cape ivy, a noxious weed related to fireweed, and containing the same toxic properties. “It’s inedible for livestock,” says Crow of the ivy. “We don’t want it. Plus it’s a threat to higher elevation native forest.”

The moth’s broad appetite isn’t a surprise to state agriculture officials. Before Secusio was released, entomologists reared the caterpillars in captivity to test what plants they would eat. Confined in cages with 88 different kinds of plants (71 of which were related to fireweed), they found it only ate 6 different species, including Cape ivy, and all were closely related to fireweed. Any plant it caused significant damage on is considered a weed in Hawai‘i.

Also known as German ivy, Cape ivy is extremely invasive. Introduced at the turn of the century to Kona, Cape ivy escaped cultivation and now threatens watersheds and native forests on the Big Island and Maui. It spreads quickly and once established can be extremely tenacious. Pat Bily of The Nature Conservancy has found several small populations in the Waikamoi preserve. Using herbicide to control a smothering vine would damage native vegetation so Bily removes plants by hand. Every leaf, stem, and root have to be removed or the plant resprouts; eradicating a handful of small populations is taking Bily years.

“Any feeding on Cape ivy, even if it was low, is a benefit,” explains Rob Curtiss. “Cape ivy certainly can be an alternate host. If populations of fireweed go down and there are populations of Cape ivy in the area, they will sustain a larger population of Secusio and we’ll get a better impact on fireweed.”

How do you know if you have them? The larval stage of Secusio is a fuzzy black caterpillar

The Secusio moth is about the size of an almond with mottling on the wings. The moth is nocturnal; turning off lights in the evening will encourage the moth to return to fireweed plants  to lay eggs. Photo courtesy of HDOA

The Secusio moth is about the size of an almond with mottling on the wings. The moth is nocturnal; turning off lights in the evening will encourage the moth to return to fireweed plants to lay eggs. Photo courtesy of HDOA

with an orange head and sometimes orange feet. It ranges in size from 1/8th inch when young to just over 1 inch before pupating into a moth. The moth is beige with brown mottling on the wings and about the size of an almond.

Are other plants on the menu for the Secusio moth? Seeing the caterpillar on other plants doesn’t mean the caterpillar is feeding on them. According to Curtiss, most feeding happens at night. The caterpillars often leave the host plants during the day to avoid potential predation.

People may also see them when the caterpillars are looking for a place to pupate, preferring a dark place like a garage or shed. “If you see them, leave them alone or take them outside,” advises Curtiss. The moths are nocturnal and attracted to light so leaving outside lights on all night may keep them close to houses rather than seeking out fireweed in adjacent pastures.

For more information about the Secusio moth, visit the HDOA website: http://hdoa.hawaii.gov/blog/news-releases/2013-news-releases/biocontrol-moths-released-on-maui-to-fight-invasive-fireweed/

By Lissa Fox Strohecker. Originally published in the Maui News, July 13th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

The little fire ant-bad news for food crops

Liitle fire ant colony inside a macadamia nut

Little fire ants have many queens in the colony, and by moving a queen the population spreads to new areas. If you live in an area infested with little fire ant, don’t bring the pest to your new home. Photo courtesy of Hawaii Department of Agriculture.

The little fire ant, Wasmannia auropunctata, is a pest with a deservedly nasty reputation. Alone, this wee ant is neither aggressive nor impressive, but with her sisters, living in a network of colonies stretching from tree-top to ground, she has a dramatic impact. Once established, little fire ants are more than a pest, they will put the kibosh on agriculture. Little fire ants have already shut down fruit orchards in the Hilo area and their establishment threatens agriculture throughout the state.

Little fire ants do not compete between colonies; rather, they cooperate, blanketing the ground and trees and outcompeting other ant species for food and resources. Other insects and animals may also be pushed out and end up abandoning highly-infested areas to the little fire ant.

As little fire ants find homes in bananas, citrus, rambutan, and coffee trees, farmers faced with new difficulties in harvesting their crops. Because the ants don’t hold on well to branches, scads of tree-dwelling ants rain down on workers become trapped in their clothing, and sting in self-defense.

fungus on coffee infested with little fire ants

Stinging ants raining down upon harvesters is enough of an obstacle for coffee infested with little fire ant, but additionally, yields are reduced because little fire ants protect aphids that support plant disease, like this fungus. Photo by Cas Vanderwoude

In the Galapagos, little fire ants have made harvesting coffee one of the most difficult ways to earn a living; coffee harvesters now command a higher wage than other agricultural workers to compensate them for the aggravation. Increased costs affect farm profitability; in several areas of the Galapagos, coffee plantations lay abandoned because of the little fire ant. In Kona, the famed coffee-growing area, and elsewhere in the state, most coffee is harvested by hand. The spread of LFA into coffee plantations will be a huge blow to an industry already struggling to address the coffee borer beetle, another invasive pest that threatens the coffee industry as it reduces yields.

Little fire ants threaten more than just coffee. In Brazil and Cameroon, little fire ants infest cacao farms. In Puerto Rico, Florida and New Caledonia, little fire ants have overrun citrus

Cacao and other tree crops are particularly susceptible to little fire ant infestations. Photo used by permission from  Cas Vanderwoude.

Cacao and other tree crops are particularly susceptible to little fire ant infestations. Photo used by permission from Cas Vanderwoude.

groves and in some areas practically blanket the ground.

The ants are causing havoc with other types of agriculture as well. Little fire ants cause blindness in animals and livestock, poultry, and pets in infested areas have a much higher incidence of blindness than do animals without LFA.

Controlling these ants is extremely difficult, especially for tree crops, as few pesticides are registered for use in trees and the bait must stick to branches long enough for the ants to find it. Existing control techniques rely on traditional pesticides; an effective organic method has yet to be developed.

As with any invasive species, preventing spread and establishment are the most cost-effective approaches.  Eradication is possible only if the population is small. Once established, these ants may be forever.  Little fire ants are widespread on the eastern side of Hawaii Island and beyond eradication in that area, but further spread throughout the state can be prevented. Help protect agriculture on Maui, as well as your own quality of life. Support efforts to prevent their movement between islands and quarantine and check any plants or soil you bring on to your property for little fire ants. Learn more at www.lfa-hawaii.org and www.littlefireants.com.

By Lissa Fox Strohecker. Originally published in the Maui News, May 13th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Invasive plants=Less water

Open canopy rainforest in Puu Kukui

This rainforest, in Puu Kukui on West Maui, is an example of an open canopy rainforest typical of native rainforest in Hawaii. This forest acts like a ‘sponge,’ absorbing water from rain and gently releasing to recharge streams and aquifers. MISC file photo

When rain falls from the sky by the bucket-load it can be tempting to take water for granted, but the trip from raincloud to tap relies on effective, functioning natural systems. In Hawai‘i, alien plants disrupt the forest’s ability to capture water.

Water follows a cycle through the environment. Water over the ocean evaporates becoming atmospheric moister, as it travels over land it condenses into clouds, falling to Earth as rain or fog drip. Once on the ground, water has three paths: 1) it’s taken up by plants that use it to move nutrients through their cells, then return it to the atmosphere via transpiration; 2) it fills streams, lakes and rivers, eventually returning to the ocean–minus what was used for irrigation or lost through evaporation; or 3) it seeps through the soil into underground pools called aquifers. These aquifers supply most of the water we use to drink, bathe, and grow our food.

 

Forests have evolved differently to take advantage of prevailing water cycles in their regions. In South America and Africa the greatest diversity of plants is found up in the canopy.  In Hawai‘i most plant species are found in the lower third of the forest, closer to the forest floor.  Hawaiian understory plants need sunlight filtering through an open canopy. Koa and ‘ōh‘ia, the dominant Hawaiian canopy trees, grow in such a way that light reaches the shrubs and groundcover below.

Koa and ‘ōh‘ia  pull water from passing clouds as fog drip; the curved leaves of koa provide surface area to collect moisture from clouds and channel it down leaf tips to the forest floor. Spongy plants on ‘ōh‘ia branches and trunks absorb moisture from passing clouds. Alien species disrupt the system.

Strawberry guava, Psidium cattleanium, has invaded Hawaiian rainforests, growing so dense and so

Strawberry guava invaded forest in Makawao Forest Reserve

The invasive tree strawberry guava chokes out native plants. As it sheds bark, strawberry guava provides no habitat for the plants growing on the trunks of native species. Photo courtesy of Forest and Kim Starr.

fast that it chokes out other plants. A strawberry-guava-invaded forest captures water differently than our native forests. In Hawai‘i Volcanoes National Park researchers found that a forest dominated by strawberry guava delivered less water to the forest floor than an intact native rainforest. Researchers noticed several differences between the two forest types: more rain ran down the stems of strawberry guava than ‘ōh‘ia but less water was pulled from the passing clouds. This could result from structural differences. ‘Ōh‘ia have aerial roots and furrowed bark carpeted with mosses and small plants called epiphytes. The epiphytes and aerial roots soak up water from passing clouds. Strawberry guava bark is smooth and regularly shed; few plants grow on its trunk and branches.

Other invasive species disrupt the water cycle by sheer size—leaf size. Miconia trees with three-foot long leaves sweep into the forest, stealing light from the understory and transforming it into darkened forest, the soil bare but for miconia seedlings. As another researcher on Hawai‘i Island discovered, the huge leaves are more than just light-hogs. They collect water as if they were huge tarps, and, as anyone who has stood near the edge of a tarp in a rainstorm knows, it’s only a matter of time until the water

The forest floor under a miconia invasion is bare, often with exposed roots. Not a good sign for water collection. MISC file photo

The forest floor under a miconia invasion is bare, often with exposed roots. Not a good sign for water collection. MISC file photo

dumps down. The drops running off of miconia turn out to be the largest drops ever measured. Larger drops hit the ground harder, and where miconia has smothered the understory, those drops fall on bare soil. Huge drops compact soil particles, preventing water from seeping down to aquifers, instead causing it to run off, carrying topsoil into streams and eventually the ocean where it can smother coral reefs.

These are only some of the ways invasive plants alter the forest’s ability to capture water. Water-hungry plants like Himalayan ginger pave the forest floor in tough roots. Huge trees like eucalyptus require more water to carry nutrients to their crowns than smaller trees. Unfortunately, the list goes on. Healthy forests mean reliable sources of water. Keeping invasive plants out of native forests is one way to help keep the water flowing from raincloud to tap

By Lissa Fox Strohecker. Originally published in the Maui News, March 11th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee

Flower grower who detected little fire ant in December 2013 receives award

Masako Cordray, 2014 Malama i ka Aina Award Winner

Masako Cordray, 2014 Malama i ka Aina Award Winner

 

Farmer and flower grower Masako Cordray was the 2014 recipient of the Malama i ka Aina Award, presented Saturday June 14th in  a ceremony at the Maui Association of Landscape Professionals’ Lawn and Garden Fair held at the Maui Mall.

 

The person nominating her said “Masako’s passion for land stewardship extends beyond the boundaries of the land she farms to the entire island.

 

On December 23, 2013, Cordray tested plant material she had recently purchased for little fire ants. After finding small orange ants on peanut-butter coated sticks she contacted MISC. Confirmation of the detection by the Hawaii Department of Agriculture set off a chain of events that resulted in the discovery of little fire ants at other garden shops and nurseries on Maui and Oahu and has sparked a statewide response “The 45 minutes she took to sample plant material has had immeasurable consequences. This is truly an example of the contributions one person can make” said MISC manager Teya Penniman.

Cordray has influenced invasive species prevention efforts for many years. She was part of grass roots efforts to incorporate an improved biosecurity facility when the Kahului airport was being expanded–actions that led to the completion of the Hawaii Department of Agriculture’s state of the art inspection facility completed in 2007. In addition to being a farmer, Cordray is an award-winning photographer and videographer and donated much of her time to helping educate the public about invasive species. She worked to create a film about miconia in 2006 and when little fire ants were discovered on Maui n 2009, she approached MISC about creating a film about this devastating species. A true artist, her attention to detail and uncompromising standards are evident in the quality of her work, both

(L-R) Allison Wright, MALP; Masako Cordray; Teya Penniman, MISC; Rob Parsons, County of Maui. MISC file photo

(L-R) Allison Wright, MALP; Masako Cordray; Teya Penniman, MISC; Rob Parsons, County of Maui. MISC file photo

in her photographs and floral arrangements.

 

The Malama i ka Aina Award is presented annually to recognize an individual or business working within the landscape or agricultural community to keep invasive species out of Maui County.  The award is sponsored by the Maui Association of Landscape Professionals (MALP), the County of Maui, and the Maui Invasive Species Committee (MISC).
This year’s award featured a glass sculpture of an endemic Hawaiian damselfly, or pinao, by local artist Jupiter Nielsen. Award presenters were MALP Vice-President Allison Wright, Maui County Environmental Coordinator Rob Parsons, and Penniman.

Press Release – 2014 MIKA awardee Masako Cordray_final