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.

Invasion: Little Fire Ants in Hawai’i [video & transcription]

[Transcription] There is a new, invasive, stinging ant now established on the Big Island that threatens the environment, the economy, and the way of life on all the Hawaiian Islands.

How could this be? How could I not know about this? How could this be something that’s going to threaten me so badly and I’ve never heard of it?

When you look in the grand scheme of things, the nastiest of the invasive ants, with the greatest impact on Hawai’i is the little fire ant.

http://www.LFA-Hawaii.org/

A guy came in with his back completely covered with fire ant bites. I would guess two hundred, three hundred bites.

They’d crawl up our legs, they were on our couches, in our beds, in my dresser. Millions of ‘em. They were just everywhere.

I’ve been the manager of the Maui Invasive Species Committee for more than a decade. Working with an amazing team of people, staff, partners, working to control and eradicate the most harmful species across Maui Nui. I’ve had the opportunity to work on issues statewide. Traveling to Big Island, Kaua’i, and Tahiti, I’ve seen just how devastating the little fire ant can be and my concern has only grown. I’m now convinced that without an extraordinary effort, the little fire ant will be a catastrophe for Hawai’i.

The little fire ant is native to South America. Moved by human travel and commerce the ants have spread to many islands in the Pacific with devastating impacts. In 1999, little fire ants were discovered in Puna on the Big Island. Now they are widespread in Hāmākua, Hilo, and Puna, from Waipi’o to Kalapana. By 2011 they had spread to Kona and are now established in many sites. In 1999, they were found in Kalihiwai on Kaua’i, and in 2009 a small infestation was confirmed in Waihe’e, Maui.

Dr. Cas Vanderwoude in an expert on the little fire ant who has worked on ants throughout the Pacific. He is now based in Hilo as Hawai’i’s ant specialist.

I was working on a project in New Guinea and the locals there took me to a place that was infested with little fire ants. And the impacts were so extraordinary, the problems that this species caused were so huge, that it was sort of a bit of a turning point for me, I guess, and from that time onward I spent more and more of my time working researching ways to control this species and also looking at the kind of impacts this species has on both people, and on the environment, and on agriculture.

Now with little fire ants, we have colonies with lots and lots of queens. So if one queen dies, it’s not that important because there are other queens that will take her place. And those queens will stay with that parent colony, or walk away a few feet, or a few yards so that they remain connected to the parent colony all the time where really most scientists would consider that network to be a single colony and we would call that a super colony. Super colonies can span many aces, many thousands of acres in some cases where all the workers you would find all work together and cooperate with each other.

The Hawaiian Islands are in the early stages of infestation. Unless we stop their spread, little fire ants will form massive super colonies on each island changing Hawai’i forever.

Most ants like open, sunny, kind of drier places, but little fire ants are much more of a rainforest species. They like it shady, they like it wet, and they like to live in trees, which again, most ants will nest in the ground and then actually forage on trees but these will look for places to set up their nests in the trees themselves. For an arboreal species, for a species that like to live in trees, they’re not actually very good at hanging on. So even a small bump to vegetation will result in a rain of these little ants falling down onto the person or the animal that’s bumped the tree.

We got rained upon by all of these fire ants. We didn’t know what it was, but it was very, very painful it was. Like burning after that, just had to go take a shower and it still was burning after that.

The sting’s actually very small and a lot of people don’t notice that it’s an insect that stung them. What they end up with is, a few minutes after being stung, they end up with a rash.

It was like, what is this rash? Intensely itchy, painful rash. And the itch, if you can not scratch is manageable, manageable if you don’t scratch. But kids scratch and adults scratch. And you know it’s just very hard to not go, I have a fire ant bite right here, it’s very hard for me to not dig at it right now cause it’s itching me.

They were so itchy, they were so, so itchy and I mean even a day or two after I got bit they were still itchy. They hurt for a long time and they leave scars, too cause I would scratch them I guess.

The pattern of fire ant bites is that they disappear for a while and then they come back, they disappear for a while and then they come back. And over three or four days, on day three it can be just as itchy as it was on day one. The next level of concern is infection, that’s when people dig at it. And around here when you have an open sore, you’re going to get infected. You’re gonna get a staphylococcal infection and then chances are really good that it’s gonna be MERSA and so that’s what we are dealing with at the clinic.

Yeah, well I remember the first time Michaela got bit by a fire ant. It bit her on her chest and it swelled and it was red and it was really angry looking and I think she was maybe not even a month old, I think, and I just freaked out.

You know we’d sit and the couch and you’d look on the ground and you’d see ants, you know, right under you. So we couldn’t put her on the ground.

You’d have to dust your feet off before you sat on the couch or got into bed. Shake your towels out, your clothes out. They were just everywhere. It was everywhere.

Now, it’s just really a prevalent problem. They’re everywhere. I think everybody would have a story about an infestation in their homes, in their cars. They’re all over in the schools. Prior to the very recent treatment of this school, they were in my classroom. It’s challenging in an elementary school and an edible garden. I had to let all the parents know, we have this problem. If you kid comes home with a…you know, make sure that none of them have allergies. But everybody at one point or another got a bite or two. The custodians, I mean they a hard time maintaining the campus because all of the foliage around the campus was just loaded.

So, when they did the septic tank they brought in materials and they brought in cinder, so I’m thinking that they probably brought in the ants too. We never had that problem before. And then whatever we move around, the materials, you spread around for the campus, so we probably spread it more.

People are being stung in their homes, at work, and in parks. Public land and wild places may be abandoned to the ants. Hunting, hiking, and even beach trips will not be the same. The ants have already infested parks in the Hilo area.

We notice because it’s around out tower. And then for some of the people that lay out on the grass or sometimes they lay out on the far side, over there and they come telling us they’re getting bit. It falls off the trees, too, sometimes. It falls onto the beach patrons and they come up, something’s burning their neck and…[sigh]. It’s a really bright, bright day you see the little ant cause it’s really small. That thing actually went with us to our homes. That’s the, that’s the bad part. In our cars. They spread and end up in your bed and you get a bite in the night and not a good feeling. Yeah, it’s getting worse, it’s getting worse.

But for people that live a subsistence lifestyle, that live, you know, very firmly connected with the land, that produce most of their own food and the things that they need from their own land. And they have to suffer the crop losses or the economic losses or the production losses and there’s not a lot that they can do about it.

Everywhere, there’s not, not one spot without ants. If he didn’t treat, he’d have no life, no income. So, t he ant has been here for six years and he’s been able to contain it right on his property and trying to find a way to get rid of it.

Some of the people I talk to they feel really trapped because they don’t have the ability either financially or technically to actually deal with these issues, so it just adds an extra burden to their life.

They don’t even want to eat their bananas any more. The pineapple is full of ants. The ants get into the taro. What was it like before the ants came, living here? A lot of food. It was really nice. A lot of food. Paradise. It was paradise, but they don’t give up. How long has the land in this area been a part of her family? Generations. How often do you get stung? Everyday, everyday, everyday. When the wind is really strong, don’t come outside. A lot of people have abandoned their land already. Her cousin abandoned his land, up there they abandoned they’re land. They left. They don’t wasn’t to live here anymore. They gave up.

So Tahiti is the most populated island in French Polynesia. It is also the biggest one with the tallest peaks and mountains, so it has the richest biodiversity in French Polynesia. We’ve got about 850 native plants including 550 endemics. If some colonies are accidentally moved to those higher elevation areas it would be an ecological disaster.

Like Tahiti, Hawai’i is an evolutionary showcase with an exceptionally high number of plants and animals found nowhere else in the world. Little fire ants have the ability to transform and decimate native places and species. Forest birds and ground nesting sea birds are at risk along with sea turtle hatchlings. Even the smallest creatures, bugs, beetles, and spiders are vulnerable. In some infested areas of New Caledonia, little fire ants now dominate, making up more than 90% of insects with impacts cascading throughout entire ecosystems.

Hawai’i’s got quite a remarkable number of seabirds for the area. We have 23 breeding species of seabirds. Probably 20 would be directly threatened by ants in a large way. And all of them have this really long incubation period and long defenseless period. This about a month old chick of a wedgetailed shearwater and you can see it’s pretty helpless. There’s no tail feathers or wing feathers. A big, fat, ball of down. These birds are particularly susceptible to ants during the period of time when the egg is ready to hatch. It makes a hole in the egg shell which allows ants and things to actually enter it and to start directly attacking the chick inside of the egg. If ants were to get into some of the of the low wet forests like I’ve heard that they’ve done in other areas, they may be the thing that would push Newell Shearwaters and low elevation nesting Hawaiian Petrels or other endangered species over the edge.

The effect that it has on pets. The blinding and I’m sure it’s got to be very painful for them to be constantly being bitten or stung.

At start she was loving to go in the bush. Now she stays home. She is blind.

One time we did witness a bite on the eye. He came in right after and just ferociously rubbing his eye. You know, he was in a lot of pain for a while. You could tell. A few hours, sat and just licked and rubbed his eye.

The black one who is affected the most, if I pick him up, it never fails, he’s got fire ants in his fur. I’m bitten every time I pick him up.

Every single animal we have, we have three cats and two dogs and every single one of them has a, have clouded cornea. There’s no question that the fire ants and the clouded cornea come together I don’t know how you prove it.

Being here I know, I know that’s what ‘s doing it. Feeling the stings, I’m sure that it’s the fire ants.

We’re animal lovers, yeah. They’re very much a part of the family.

When I first heard that the little fire ant had arrived on Maui, my heart sank because I knew what a threat it posed and knew what the challenges are associated with trying to control a pest species that is so small, but that can be so powerfully damaging.

When we were making a banana delivery my glasses had dropped to the ground and when I picked them up and put them on I got bit on the eye. And it was so severe. I had to, like, run to the house and put ice on my eye. I had to lay down and the thought came that, I wonder if this is the fire ant. Initially when they came out to do the testing, so they put the peanut butter sticks everywhere, where we felt the ant, we’d experienced the ant. And it came back positive. It was evident that the destruction that the fire ant can bring to an island, which is what’s happening on the Big Island is something we did not want to happen here on Maui. Then whatever contribution we could make to help prevent the fire ant from coming to Maui we were gonna make.

So Maui was a good small scale test case. And Kaua’i presents a good opportunity for a large scale test case on eradication.

Right here we’re on Kalihiwai Beach. It’s a beautiful sandy scape and it abuts this cliff side area. The ant infestation is actually along that cliff line around the corner.

And as I got to the bottom of the cliff where i go holoholo and I could feel some bites all over my shoulders and my back and I was like, ho, what is this? And then I could see some ants was on top of me. When it’s wet, you’re always grabbing trees, grabbing the rope, so I guess that’s what kinda makes ‘em all come down too on you. And you’re getting bit going down the trail and it’s like, ahhh. That’s the trail we use all the time and that would be the trail I would take my son down there and having the ants fall on top of him and getting bit up, that’d be a big concern for me. I wouldn’t want that happening.

Well, some landscaper came and you know, landscaped the property down below here and two fire ants were in that particular plant and now we have a colony. It’s really bothered us and so I asked that question. How and why, where did this fire ant come from?

Historically, the little fire ant arrived to Kaua’i in 1999 on a shipment of palms. So the original infestation was only about five acres. It was believed to be eradicated, but what had actually happened was that it was brought to undetectable levels. And unfortunately now it’s about twelve to fifteen acres. Without Department of Ag’s containing it on that edge, it would have spread across that property and on to the next one. It would be devastating to have it infest this area, one of the nicest beaches on Kaua’i.

Farming is woven into Hawai’i’s history and is key to a sustainable future. Healthy are a critical component of farming. The pollination of crops, honey production, and Hawai’i’s Queen Bee industry face a new threat.

The bee industry is important wherever you are. All our hives have succumbed to LFA because LFA is a protein eater and the larval stage of the bees are very susceptible. If you have LFA and they’re close to your hive and they can get up and into that hive, they’ll probably take your hive down. I think it’s much more dangerous than the varroa mite.

Both local and export agriculture and our hopes for food security are at risk because of the little fire ant. In addition to stinging agricultural workers, little fire ants can weaken plants by farming insects like aphids and mealy bugs.

Those insects secrete a sugary substance that the ants use as a source of energy. So the ants have a huge source of energy that allows them expand and grow and farm yet more mealy bugs and scale insects which makes the plant sicker and sicker. That decline in health could result in quite substantial crop losses.

I grow macadamia nuts, coffee. I have lychee, mangosteen, orchids. Just a little bit of everything. A diversified crop farm.

I was going to grow four to eight acres of palms for hearts of palm, a couple acres bamboo nursery. So by the time we discovered them, we had millions and millions and millions. The palms are not harvestable because of the ants. I’m out of business. Totally. Little fire ant.

Now I have fire ants in my lychee crop. You’re in there with the panicles and you’re trying to grab your lychee and cut it and all that. You get them on you. I watched them as they were shaking all these ants off of them. And basically it was raining ants. Raining fire ants on them from the lychee.

The cost of trying to actually control fifteen acres when there are literally, you can ask Cas, but I’m sure hundreds of thousands in one tree. And finding people willing to work in the orchard is extremely difficult. I really think that this is the most devastating invasive that we have.

When I heard about the little fire ant I was really appalled and really scared. We’d be in very big trouble if it came into our coffee lands. We harvest off the tree and these branches are always leaning over us. Harvesting anything from a tree is going to be very, very, very difficult. And it will greatly impact agriculture. I mean, agriculture as we know it will not be here.

Wearing my hat as the chair of the board of agriculture, I see little fire ant as being a very significant threat. We need to address this quickly.

When you look at our mandate, what is it to do? It’s not just to protect agriculture, it’s not just to protect the environment, it is to protect the native biota, it’s to protect the public health. We can’t do it all. And that is very frustrating. It’s hard choices. It’s choosing between snakes or between, do we look at all the fish coming in because they may have pirahnas in them. Or do we look about what we’re not doing now which is the weedy plants. We’re so dependent on food, imported food, that we can’t let our stores or restaurants go empty. So we’re forced to get it out. Whether or not there are pests on them, we’re forced to get them out. We still get a sampling of interceptions. You know things are getting through and now what do we do from here.

So invasive species and the little fire ant in particular are very problematic because they will inhibit, I think, agricultural expansion.

So I think, it is impacting our growers. I think they’re finding that the ant is moving and where they didn’t have a problem a couple years ago, I think everyone is concerned this pest is moving from area to area and how do you deal with it. I think that’s the difficulty with this. It’s the size of the pest. This particular one is so small that you really have to look for it. Because we’re already considered a high risk pathway for the spreading of pests to the continental US, the presence of little fire ant in these nursery shipments or these flower shipments has heightened the concern that it will cause a California embargo.

California’s gotten very, very restrictive in terms of what we can export from Hawaii to their markets. So they’re, you know, they’re really kind of on the verge of closing us down.

If they find out that they cannot export their crop. Or, or sell it, at all. I think they’ll be very concerned. But because most people don’t have it, or haven’t been stung, bitten, they don’t know the effect. they don’t know that this is a very serious insect.

Because our islands are connected, you have to have real, meaningful, ongoing inspection, detection, reporting capabilities, because without that we will get it. It will become established and it will spread in the Pacific.

The ant is essentially gonna be, is here to stay on the Big Island and that’s just the reality and what we’re gonna be doing is mitigating effects, essentially forever. What we need is a good detection network so we can respond quickly and eradicate it before LFA gets a good foothold.

To do that we need more support for our inspectors. We need more inspectors. We need sniffer dogs, dog detectors and handlers. We need to have the industry, the shipping industry to be involved and supportive. We need to stop [the ants] from moving between islands. And that’s why it’s so important for people everywhere to become aware of what it looks like, what it does, how to report it, and to demand the tools and the resources to address it when it does become established. We need support from our legislators, our elected officials, county officials, federal officials, and we need everyone to be involved.

There’s on thing that that little ant really loves, and it’s peanut butter.

So you take a chopstick and thinly coat it with peanut butter on one end and lay it in the areas where you think you might have little fire ant. Be it a potted plant you’re bringing onto your property or a banana tree you’ve already planted or a palm you’ve already planted, they really do like moisture. It’s really not difficult, at all. Within forty five minutes, the sticks will have the little fire ant on them. They’re very small, but you should be able to see them. And of course if you do find them, you want to put that little stick in a plastic bag, freeze it to kill it, and then send it to the Department of Agriculture so that they can make a positive ID because there actually are quite a few stinging ants on the islands and they’re only able to actually positively ID them with a microscope.

We need for people to understand just how serious this problem is and to ask, demand, support action to stop it now while we still have a chance.

http://www.LFA-Hawaii.org/

Premiere of the new documentary Invasion: Little Fire Ants in Hawaii

LFA Premiere invitationIn 2009, Waihee farmer Christina Chang was stung on the eye by a tiny ant at her home on Maui. She suspected, and the Hawaii Department of Agriculture confirmed, that this ant was the little fire ant, Wasmannia auropunctata, never before found on Maui. The detection spurred creation of a new documentary, Invasion: Little Fire Ants in Hawaii.

Invasive species introductions to Hawaii often end in regret and a list of should-haves. This film, produced by the Maui Invasive Species Committee, aims to change the result of the arrival of little fire ants in Hawaii. Featuring videography from award-winning film makers Masako Cordray and Chris Reickert, this half-hour film examines the biology, impacts, and potential solutions to the spread of little fire ants through interviews with scientists, farmers, and community on the Big Island reeling from the impacts of this miniscule, but devastating, ant. Viewers will learn how to identify and report new infestations, helping to protect Hawaii from this small stinging ant

The Waihee site is on target for eradication. However, little fire ants have recently been detected moving between islands, raising concern about the establishment of new infestations. On Hawaii Island, the little fire ant is now widespread in the Hilo area where efforts are focused on educating landowners about control options.  Infestations are now occurring on the Kona side as well. Research on effective control continues by the Hawaii Ant Lab, a joint project of the Hawaii Department of Agriculture (HDOA) and University of Hawaii. The little fire ant on Kauai is contained within a 12-acre area under active control by HDOA

The film will premiere on Maui January 8th at the McCoy Theater at the Maui Arts and Cultural Center. Doors open at 5pm. An awards ceremony and panel discussion will follow the screening. Food and beverages are available for purchase on site beginning at 4:30pm.

Screenings on other islands will follow. Please RSVP to miscpr@hawaii.edu to reserve a seat. Below is the current screening schedule:

  • Maui: January 8, McCoy Theater and the Maui Arts and Cultural Center, 5pm
  • Oahu: January 13, Cafe Julia at the YWCA, 1040 Richard St, 4:30pm
  • Kauai: January 18, Kauai Community College Performing Arts Center
  • Hilo: TBA (February 18)
  • Kona: February 19, Aloha Performing Arts Center, 5pm

The film will also air throughout the state on KITV

Sat 1/11                630-7PM

Sunday 1/12       9-9:30AM

Sat 1/19                4-4:30PM

Sunday 1/20       10:30-11P

Funding and support for the film was provided by the Hawaii Department of Agriculture, County of Maui-Office of Economic Development, US Fish and Wildlife Service, Hawaii Community Foundation-Pikake Fund, Maui Electric Company, Alexander and Baldwin Foundation, Tri-Isle RC&D. MISC and the Hawaii Ant Lab are collaborative projects of the Pacific Cooperative Studies Unit.

Tiny beetle bores down on Hawaii coffee industry

tiny coffee berry borer beetle is seen here entering the coffee fruit.

The tiny coffee berry borer beetle is seen here entering the coffee fruit. Coffee berry borer eats the coffee bean, reducing yield dramatically. In four months’ time one beetle will produce 40,960,000 beetles. This pest is only known to be on Hawaii Island and coffee farmers throughout the state are on the lookout. Never bring green coffee or plants between islands. Photo by Andrea Kawabata, UH CTAHR.

Hawai‘i is the only state in the United States where coffee is grown commercially, and Hawaiian coffee, often synonymous with Kona, is beloved throughout the world.  Coffee farms have started springing up on Maui in recent years. “There are maybe 20 times more coffee farmers than 10 years ago,” says Sydney Smith, owner of Māliko Estate Coffee and president of the Maui Coffee Association.

But a tiny bark beetle from Africa, Hypothenemus hampei, or coffee berry borer threatens the coffee industry throughout the state. The miniscule pest was first detected in Kona in 2010. It spread like wildfire reaching north Kona, Ka‘ū, Hāwī, and Hilo. The beetle lays eggs inside of coffee berries. Its larvae hatch and begin to feed, hollowing out the bean and leaving little to harvest and roast.

“Once infestation levels exceed 50% of the cherries in the field, the coffee is not worth picking,” says Rob Curtiss, entomologist with the Hawai‘i Department of Agriculture (HDOA).  He explained that there are farms on Hawai‘i Island with 80-90% infestation.  “After [the beetles] are in the coffee [fruit] there is nothing you can do to kill them.”

People are responsible for spreading coffee berry borers, says Curtiss. Moving infested beans and bags moves the insects. A few infested beans in the back of a pickup truck could mean the introduction of the pest to a new farm—where the beetle population then explodes. Each female can lay 120 eggs, of which there are 10 females for every male. When the females mature, they find a new coffee fruit, tunnel inside, and lay eggs immediately. Their life cycle is approximately 27 days, most of which occurs inside the coffee berry. “Every 30 or so days you can multiply the infestation by about 80,” says Curtiss. “In four months’ time one beetle becomes 40,960,000 beetles.”

Coffee farmers in Kona have been working closely with entomologists and researchers at the Hawai‘i Department of Agriculture and the University of Hawai‘i-College of Tropical Agriculture and Human Resources (UH-CTAHR) to find effective ways to manage the infestation.

By combining several methods of control, some farmers on Hawai‘i Island have successfully reduced infestation levels to below 5%. This system of integrated pest management includes protocols for field sanitation, pruning, monitoring, pesticide application, harvest, and shipping. Instructions can be found in an online publication on the UH-CTAHR website titled “Recommendations for Coffee Berry Borer Integrated Pest Management in Hawai‘i 2013”

The long-term solution may lie in the discovery of an effective predator for the beetle.  According to Curtiss, coffee berry borer is an ongoing target for biocontrol research for the Hawai‘i Department of Agriculture. The department’s exploratory entomologist may someday make a promising discovery in Africa, the beetle’s native range.

Currently, an interisland quarantine restricts the movement of coffee plants and unroasted or untreated “green” coffee from Hawai‘i Island to prevent the pest’s spread to other islands.

Back on Maui, Sydney Smith has changed the way she runs her farm. “I used to give tours to visitors, but I

The coffee industry on Maui and throughout the rest of the state is growing, as this farm in Kaanapalli shows. But coffee berry borer threatens the entire state. Photo by Forest and Kim Starr.

The coffee industry on Maui and throughout the rest of the state is growing, as this farm in Kaanapalli shows. But coffee berry borer threatens the entire state. Photo by Forest and Kim Starr.


don’t do that anymore…I’ve removed coffee plants from near our vacation rental.” Smith’s actions stem from concerns that a visitor may have toured an infested coffee farm on Hawai‘i Island and unknowingly be transporting a beetle. “They’re little tiny things that can get in shoes and clothes.”

Coffee berry borer has thus far only been detected on Hawai‘i Island, but Maui coffee farmers have been trained on what to look for. “It’s not if—it’s when,” says Smith.

To learn more about coffee berry borer, visit the UH-CTAHR webpage: www.ctahr.hawaii.edu/site/cbb.aspx and the HDOA webpage: hdoa.hawaii.gov/pi/ppc/coffee-berry-borer-information-page.

By Lissa Fox Strohecker. Originally published in the Maui News, November 10th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

The public health threat of invasive species-mosquitoes and dengue

Aedes aegypti is famous the world over for spreading dengue.

Aedes aegypti is famous the world over for spreading dengue. This species is not established statewide, but it has shown up at the Honolulu International Airport five times since January of 2012. Photo by Muhammad Mahdi Karim

Back in 2001, several East Maui residents started reporting fever, body aches, and rashes. One of the people sickened had just traveled in French Polynesia during a dengue fever outbreak. The Department of Health eventually confirmed 20 cases of dengue fever in East Maui and a crew hired with funds allocated for environmental emergencies went to work removing mosquito habitat. What made this outbreak interesting was that it was spread by the tiger mosquito, Aedes albopictus, common in Hawai‘i.

“We may be the only place in the world to confirm [that] dengue could be spread by the albopictus mosquito. It’s not an efficient carrier of the disease,” explains Gary Gill, Deputy Director of the Environmental Health Administration with the Hawai‘i Department of Health. “In places where dengue is endemic [regularly occurring], it is the aegypti mosquito that is the carrier.”

The invasive mosquito, Aedes aegypti, is famous for spreading dengue. Neither the mosquito nor dengue is widespread in Hawai‘i. Both periodically appear, but luckily not at the same time. Though conditions are prime as Hawai‘i is a global hub for tourism and commerce..

Dengue outbreaks in Hawai‘i are rare and typically occur when someone travels to an infested area, returns to Hawai‘i and is bitten by a mosquito, as happened in 2001. According to Gill, immediate family members and neighbors are at risk, but the common tiger mosquitoes rarely eat from more than one source. The female mosquito finds a person (or animal), and, given the chance, feeds until her belly is about to burst.

In contrast, Aedes aegypti flit from person to person, taking a blood meal from multiple people and spreading any disease carried by the bloodsuckers. Aedes aegypti is not normally found on O‘ahu. “We have not, up until last year, identified any aegypti since the 1940s,” says Gill.

In January of 2012, a Department of Health entomologist collected a trap containing what was later identified as Aedes aegypti at the Honolulu International Airport. “We’ve found aegypti five times in the last year.  Every indication is that this mosquito is either living and breeding at the airport, or it is regularly being reintroduced,” Gill says.   Mosquitoes can survive in the cabin, cargo hold, or underbelly of an airplane coming from an infested area. Aedes aegypti are originally from Africa but have spread to tropical and sub-tropical regions of the world including Mexico, Asia, and Australia.

Dengue fever is a widespread subtropical disease that is continuously present in areas with established population of Aedes aegypti.  This map shows the distribution of Aedes aegypti (blue) and Aedes aegypti and dengue fever (red). Image from Centers for Disease Control

Dengue fever is a widespread subtropical disease that is continuously present in areas with established population of Aedes aegypti. This map shows the distribution of Aedes aegypti (blue) and Aedes aegypti and dengue fever (red). Image from Centers for Disease Control

From a public health standpoint having a thriving population of dengue-spreading mosquitoes at the airport is a worst case scenario according to Gill. “A person carrying the virus walks through the airport, and then it spreads to any number of people at the airport who will then take it to wherever they are going. A single population of aegypti could easily spread dengue throughout the state. A dengue-carrier mosquito would be a concern for people who come here as much as for people who live here.”  If Aedes aegypti became established throughout Hawai‘i, it would set the stage for a consistent presence of dengue, like does in parts of Central and South America, India, Southeast Asia, and Africa.

Ongoing surveys for mosquitoes are the best way to ensure early detection of this species. The Department of Health continues to monitor mosquitoes at Honolulu International Airport, but surveys are limited to that airport and don’t include surrounding areas. Funding cuts in 2009 gutted the Department of Health. At one point 40 people worked on O‘ahu on environmental health but now only seven positions remain. Staff cuts throughout the state have left no capacity for mosquito monitoring elsewhere. “What’s at Kahului? We have no idea,” worries Gill.

The Department of Health is working with Hawai‘i’s Departments of Agriculture Transportation to explore options for mosquito surveys at airports and harbors statewide. They are working to reduce mosquito habitat at the airport, removing bromeliads and dark undergrowth and replacing it with less mosquito-friendly landscaping. Gill encourages homeowners to do the same, along with removing or changing water in outside open containers every week. For now it’s our best hope. Unless and until capacity is restored at the Department of Health, early detection of this devastating mosquito is up to the public.

By Lissa Fox Strohecker. Originally published in the Maui News, August 11, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Hawaiian land snails– a tale of evolution worthy of protection

The tale of Hawaiian land snails began millions of years ago as the first plants and animals began to colonize the islands. Researchers don’t know exactly how snails arrived – perhaps stuck to the feathers of a bird or on a floating tree trunk. But in a remarkable story of evolutionary radiation, some 21 or more of those first species that arrived over the millennia gave rise to more than 750 distinct species. Of those, 99% are endemic to Hawai‘i – found here and nowhere else.

This species of Newcomb's tree snail used to be widespread on Maui but today is only known from a handful of places in the West Maui Mountains thanks to habitat loss and invasive predators-rats and the rosy wolf snail.

This species of Newcomb’s tree snail used to be widespread on Maui but today is only known from a handful of places in the West Maui Mountains thanks to habitat loss and invasive predators-rats and the rosy wolf snail. Baby snails, like this one riding on mom, are rare. Photo courtesy of Hank Oppenheimer

Famously varied in color and shape, Hawaiians called them pūpū kuahiwi, or high-hill snails. Early Europeans collected these jewels of the forest, selling them as lei or to collectors. These snails are still highly valued. Current efforts focus on saving remaining species; high-elevation snail refuges are built to protect them.

Often native snails are found only on one island, or in a single valley or ridge, teetering on extinction because of habitat destruction, shell collection, and invasive species. Adding to the challenges, many Hawaiian land snails reproduce at what is truly a snail’s pace: some species are 3-7 years old at first reproduction and have only 4-7 young per year. They grow slowly—only 0.2 to 0.4 cm a year. Compare this to the invasive giant African snail (Achatina fulica) which reproduce at one year of age, lays up to 600 eggs annually, and grows about 2.5 cm per year.

One species of snail endemic to Maui, Newcomb’s tree snail or Newcombia cumingi, was once found from Lahaina to Makawao, but like most land snails, has become increasingly rare during the latter half of the 20th century. It was last seen in 1938 by Bishop Museum researchers then rediscovered in 1994 by resource managers with the Maui Land and Pineapple Company’s Pu‘u Kukui Watershed Preserve (PKW).

“One hundred years ago they [native snails] were everywhere,” explains Dr. Kenneth Hayes, a University of Hawai‘i researcher who, along many others, has been working to find out how many West Maui snails remain. Today, 50 percent or more are gone, many turned into escargot for invasive predators—rats, Jackson’s chameleons, and the rosy wolf snail. According to Hayes, the remaining native snails have mostly been relegated to the few areas that still contain native forest, but even these refuges won’t last long if we don’t stem the tide of invasive species. Native snails dine primarily on the fungi that grow on native plants. Invasive plants change the way water moves through Hawaiian watersheds altering the ecosystem by changing what plants, animals, fungi or microbes can live there. The snails’ preferred fungi may not grow in altered habitats.

Pomaikai Kaniaupio-Crozier, conservation manager with PKW, is leading efforts to protect the Newcombia. With US Fish and Wildlife Service funding and partner help they are planning an exclosure in the native forest of West Maui to keep hungry predators from munching native snails.

The West Maui “snail refuge” will be modeled after similar exclosures on O‘ahu, where the O‘ahu Army Natural Resources Program has enclosed three areas to keep out rats, chameleons, and even the predatory rosy wolf snail. A 4-foot tall sheet metal fence topped by a curved lip deters rats and chameleons. Predatory snails face sheet metal at an impossible-to-scale 10 degree angle– if they do manage they hit an electric wire. One fence is equipped with an electronic sensing system that alerts managers via text message if debris falls on the fence.

The first step in protecting Newcombia is a population survey.  “They are the size of a pinky fingernail and very cryptic,” says Kaniaupio-Crozier. “It’s like finding the needle in the haystack, looking for something that small in 8,600 acres.  Up until a couple months ago we were getting pretty demoralized.”

Then they made a remarkable discovery. They found a new population, in totally unexpected habitat. The existing Newcombia population inhabited a wet area with lots of ‘ōhi‘a; the new population was found on ‘ākia, in much drier terrain. “There’s hope there may be another population somewhere else.”

From survey to construction, building the snail refuge will take several years. You can help. PKW is welcoming people interested in habitat restoration, monitoring, even joining in the brainstorming. Contact Kaniaupio-Crozier at pkaniaupio-crozier@mlpmaui.com or by phone, 870-4225. To learn more about the native and non-native land snails of Hawai‘i, contact Ken Hayes, khayes@hawaii.edu, Norine Yeung, nyeung@hawaii.edu, or visit the Hawaiian Land Snail Conservation Facebook Page.

As with many conservation projects, the snail exclosure at Pu‘u Kukui involves many agencies and partners:  US Fish and Wildlife Service, National Science Foundation, University of Hawai‘i Mānoa, O‘ahu Army Natural Resources Program, Department of Land and Natural Resources, Plant Extinction Prevention Program, and more.

By Lissa Fox Strohecker. Originally published in the Maui News, July 14th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

The crown-of-thorns starfish–despite the prickly reputation, this species is native to Hawai‘i, and beneficial to the reef

The crown-of-thorns starfish does munch on coral, but new research is showing that this species, native to Hawai‘i, benefits the reef. Photo courtesy of the National Oceanic and Atmospheric Administration

The crown-of-thorns starfish does munch on coral, but new research is showing that this species, native to Hawai‘i, benefits the reef. Photo courtesy of the National Oceanic and Atmospheric Administration

The crown-of-thorns starfish does munch on coral, but new research is showing that this species, native to Hawai‘i, benefits the reef. Photo courtesy of the National Oceanic and Atmospheric Administration[/caption]A single crown-of-thorns starfish is impressive. This unusually large, sinister-looking sea star grows to three feet in diameter with as many as 19 spiny arms. It’s hard to miss on the reef, where it munches on coral. Crown-of-thorns have the highest fertilization rate of any invertebrate: each female can produce up to 60 million eggs during a single spawning season. When too many of these survive, it’s considered an “outbreak.” An overabundance of crown-of-thorns can spell trouble for Pacific reefs. It’s an unusual case of a native animal acting invasively in the marine environment. But it’s not clear that all outbreaks are bad or how environmental changes might exacerbate the problem.

Proliferations of the spiny creatures can destroy 90 percent of a reef, as past outbreaks in Saipan, the Marshall Islands, and Guam have shown. In situations where the reef is stressed, an abundance of coral-eating starfish can trigger a cascade of changes. First the corals go, replaced by algal overgrowth. The resulting shift in fish populations can take years to recover. In Hawai‘i and Australia, concerns about crown-of-thorns outbreaks have focused on the reduced aesthetic value of the reef, and consequently, a decline in tourism. For some communities the reef is the icebox, and crown-of-thorns outbreaks can leave it empty.

But outbreaks rarely occur in Hawai‘i. Many crown-of-thorns starfish larvae die off, while adults are eaten by triton’s trumpet snails, stripebelly pufferfish, and harlequin shrimp. A healthy reef can support small numbers of prickly stars, and it’s probable that they benefit the reef in some way. According to Russell Sparks, aquatic biologist with the Department of Land and Natural Resources Division of Aquatic Resources, “In Hawai‘i, crown-of-thorns starfish feed on fast-growing, quick-to-settle corals, such as rice and cauliflower coral. These corals can overrun other species like lobe and finger coral, so a periodic bloom of crown-of-thorns could be an important way for reefs to maintain coral diversity.”

In 2004, marine biologists observed a crown-of-thorns outbreak in ʻĀhihi Kīna‘u. “Although the coral cover impacts were dramatic, the recovery seems to be well on its way,“ says Sparks. “It may increase overall coral diversity, which should make the reef more resilient to future disturbances.”

Until recently scientists hypothesized that crown-of-thorns outbreaks in remote locations such as Hawai‘i, Guam, and French Polynesia resulted from an influx of larvae from elsewhere in the Pacific. In Australia, massive starfish outbreaks spread south along the reef in waves, seeded from larvae upstream. But new research indicates that Hawaiian blooms occur within the native population. A team of scientists from the University of Hawai‘i-Manoa looked at the genetics of crown-of-thorns starfish and found that these supposed “invaders” were actually locals—they weren’t some rogue population from across the Pacific. What does this mean?

Crown-of-thorns outbreaks are not fully understood. The species may be acting invasively because of human interference. Some biologists theorize that heavy rainfall and coastal nutrient runoff contribute to a higher than normal survival rate for larvae, resulting in a larger number of adults. Over-harvesting of the species’ natural predators could be another potential trigger. Researcher Dr. Rob Toonen recommends that marine wildlife managers “seriously consider the role that environmental conditions and local nutrient inputs play in driving crown-of-thorns outbreaks.”

You can help scientists learn more. The citizen-monitoring project Eyes of the Reef relies on reports from regular reef users to monitor reef health. Crown-of-thorns sea stars are one species of focus. Early detection of outbreaks is critical to protecting the reef. Report any occurrence of 20 or more crown-of-thorns starfish through the Eyes of the Reef monitoring project at reefcheckhawaii.org/eyesofthereef.html

By Lissa Fox Strohecker. Originally published in the Maui News, March 10th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Traveling by boat? Swab those hulls and propellers to stop invasive stowaways.

Each year over ships make over 1000 trips to Hawai‘i. Container ships and barges, fishing boats, cruise

Organisms colonize an anchor chain. Photo courtesy of Hawaii DLNR-DAR

Organisms colonize an anchor chain. Photo courtesy of Hawaii DLNR-DAR

ships, and sailboats, aircraft carriers and military ships come bearing cargo for Hawai‘i or stop over on their way across the Pacific. Any of these boats could carry tiny stowaways from distant places, and that has resource managers concerned. Even an interisland boating trip could translate into trouble for your local reef.

“The majority of Hawai‘i’s aquatic invasive species came in via ballast water and hull-fouling,” explains Sonia Gorgula, the state coordinator recently hired by the Hawai‘i Department of Land and Natural Resources’ aquatic division to address the problem. Ballast water is taken by ships at sea or in port to maintain stability, and can contain organisms or larvae that may be harmful when released into a new environment, oftentimes thousands of miles from where they originated. Hull-fouling, or bio-fouling refers to the plants and animals that grow on any aquatic vessel, be it ship or yacht, dingy or dock. When these living organisms reach new waters, they can cause problems.

Of the two types of marine contamination, Gorgula says biofouling is the bigger worry in Hawai‘i. One species introduced this way is snowflake coral, a fast-growing soft-coral from the Caribbean. Since arriving in Hawaiian waterways, it has devoured the zooplankton that supports the marine food web and destroyed numerous black coral colonies. Hypnea, the rank invasive algae that washes up on Maui beaches, spread between the Islands attached to the underbelly of a fishing or sailboat.  Hypnea is not only stinky and expensive to deal with on the beach, it outcompetes native limu.

Biofouling happens on any type of vessel, ocean or freshwater, that remains in port or dock long enough for organisms to become attached. “Broadly speaking it’s mussels, algae, barnacles,” says Gorgula. “When you start to see an assemblage become quite dense, you can even find crabs.” Boats function as floating reefs, transporting these aquatic aliens to Hawai‘i, where they may or may not find a home.

“Some species arrive and establish, then fail. Yet many species become invasive here that were not thought to be invasive until they get here,” says Gorgula. “Often there’s not enough information to predict what will become invasive.” One way to approach the situation is to treat all biofouling as harmful and focus on prevention—keeping boats with Hawai‘i on their itinerary free of small stowaways.

Biofouling is a drag, literally. Barnacles colonize the hull of a ship and reduce fuel efficiency as well as pose a risk of becoming invasive. Photo courtesy of Hawaii DLNR-DAR

Biofouling is a drag, literally. Barnacles colonize the hull of a ship and reduce fuel efficiency as well as pose a risk of becoming invasive. Photo courtesy of Hawaii DLNR-DAR

Most commercial ships have incentives to keep hulls relatively free of growth; biofouling creates drag that reduces fuel economy. But other hidden “niche” areas underneath the boat—propellers and intake pipes used to pull in water for cooling the engine and fire-fighting—often house alien species. Cleaning the hull is part of regular boat maintenance; focusing on niche areas will help prevent the spread of hitchhikers. Certain paints are designed specifically to discourage fouling, and hidden spots can be painted as well as hulls, simple steps that feed into regular maintenance.

Policies and regulations for ballast water are well established worldwide, but biofouling has only received attention of recently. One of Gorgula’s tasks is to develop policy to protect Hawai‘i. “The biofouling policy issue is complex,” she says. “Around the world, only California, New Zealand, and Australia have developed policy. Globally, there aren’t many people working on it. We’re forging new territory” In 2007 the state legislature approved rules requiring ships planning to release ballast water to exchange the water first in the open ocean more than 200 nautical miles out to sea, reducing the likelihood ballast water will contain organisms that could find safe haven in Hawai‘i

It may seem trivial n a world of big ships and global transportation, but paying attention to the details can

A diver inspects a propeller for biofouling. Photo courtesy of Hawaii DLNR-DAR

A diver inspects a propeller for biofouling. Photo courtesy of Hawaii DLNR-DAR

make a big impact. Every boat, even those going interisland can help stop the spread of invasive aquatics. “Clean off biofouling in the same port where it accumulated,” says Gorgula. Be sure to clean your hull, anchor, props, bilge compartment, and any associated gear in the same watershed to prevent its spread to other watersheds and islands.

By Lissa Fox Strohecker. Originally published in the Maui News, January 13th, 2013 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series
http://www.hear.org/misc/mauinews/

Ants and Hawaiian Seabirds–A Totally Unnatural Combination

The Hawaiian archipelago is crawling with ants and not a single one belongs here. Humans

A petrel is covered by big-headed ants on Kure Atoll. While ants can be a nuisance for people, the insects can maim or kill nesting seabirds.

A petrel is covered by big-headed ants on Kure Atoll. While ants can be a nuisance for people, the insects can maim or kill nesting seabirds.
SHELDON PLENTOVICH photo

introduced over forty-five ant species to the islands.  While they’re a nuisance to people, to Hawaiian seabirds they are a major problem.

Sheldon Plentovich is the Coastal Program Coordinator with the Pacific Islands Fish and Wildlife Office.  She has studied some of these impacts. “Seabirds nesting in Hawaii do not have effective defenses against dense supercolonies of invasive ant species,” she says. And even though high densities of invasive are present, the seabirds return to the same areas to nest as they have for generations.

In March, throughout Hawai‘i, Wedge-tailed Shearwaters dig burrows for nesting along the coastline. Unfortunately tropical fire ants, Solenopsis geminata, often inhabit these areas. Plentovich isn’t sure whether the ants are trying to eat the birds or if the ants are just defending their nest. Adult birds can fly away to escape the ants but the chicks can’t. “They’re programmed to stay in the nest,” explains Plentovich. In their fury, the six-legged invaders destroy the tender webbing on the chicks’ feet. These ant attacks affect the development of the chicks as well. Oftentimes chicks that have been attacked fail to grow feathers.

Plentovich knocked back the population of tropical fire ant on one islet off the coast of O‘ahu and, as expected, found that the seabirds had greater fledgling success compared to those on an islet still infested by tropical fire ant.

Tropical fire ants attack a wedge tailed shearwater chick on islet off Oahu. These attacks can permanently disfigure birds' feet and even lead to chick's death. Photo Sheldon Plentovich

Tropical fire ants attack a wedge tailed shearwater chick on islet off Oahu. These attacks can permanently disfigure birds’ feet and even lead to chick’s death. Photo Sheldon Plentovich

Tropical fire ants belong to a group designated as “tramps.” Tramp ants are omnivorous, and because they do not compete between colonies, form dense supercolonies made up of multiple queens. These dense supercolonies can outcompete everything else for food and resources. And since it takes a queen to start a new colony, the greater density of queens makes it easier for these ants to be spread around by people. Not surprisingly tramp ants include some of the Pacific’s most devastating invasive species, such as the little fire ant. They’ve hitched rides to the furthest reaches of the Hawaiian archipelago.

Johnston Atoll is one of the most isolated atolls in the world, 860 miles west of Hawai‘i. The Atoll is strictly a wildlife refuge where red-tailed tropicbirds nest alongside shearwaters, petrels, terns, noddies, and boobies. Unfortunately the atoll has become a haven for the yellow crazy ant or Anoplolepis gracilipes. This tramp ant doesn’t bite or sting the birds, rather it sprays them with formic acid and birds don’t respond well to formic acid.  Animals that can seek out fish from the sky are left with swollen puffy eyes. Plentovich has seen Red-tailed Tropicbirds that have “toughed it out” staying to nest despite being swarmed by ants, spraying formic acid.

Footage of a Red-tailed Tropicbird swarmed by yellow crazy ants on Kure Atoll. These invasive ants swarm nesting seabirds and spray formic acid. Seabirds show high nest fidelity and return to the same location to rear their young despite the presence of these ants. Video by Sheldon Plentovich

Ants impacts can vary from place to place. The big-headed ant, Pheidole megacephala, is one of the most common ants in Hawai‘i.  On Moku‘auia off Oahu, eradicating big-headed ant had no effect on the hatching and fledging success of shearwater chicks.

Big-headed ant attacks Bonin Petrel chick on Kure Atoll. Big-headed ants are one of the most common ants in Hawaii but on Kure the population reached such a high density the ants were attacking everything in sight. Photo by Cynthia Vanderlip

Big-headed ant attacks Bonin Petrel chick on Kure Atoll. Big-headed ants are one of the most common ants in Hawaii but on Kure the population reached such a high density the ants were attacking everything in sight. Photo by Cynthia Vanderlip

But on Kure Atoll the big-headed ant has been seen swarming birds and eating chicks alive. Plentovich thinks ant density is the reason. On Kure, the population of big-headed ants was 5 times more dense than it ever was on Moku‘auia. “They’re eating everything they encounter,” says Plentovich.

Chances are people inadvertently brought ants to isolated Johnston and Kure Atolls. All it takes is a single queen ant in a piece of cargo to start an infestation. And eradicating an established infestation is extremely difficult work. Plentovich is hopeful that new techniques will lead to the eradication of yellow crazy ant on Johnston atoll where other techniques have been unsuccessful. She’s seen how controlling an invasive ant can influence the whole ecosystem. When she reduced the population of invasive ants on offshore islets she saw an increase in the diversity of insects and “native plants survived better-the ‘ilima started taking off.”

By Lissa Fox Strohecker. Originally published in the Maui News, October 14th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series
http://www.hear.org/misc/mauinews/

A hidden world in Maui’s streams

After 27 years of working with the Department of Land and Natural Resources, aquatic biologist Skippy Hau has become pretty familiar with Maui’s streams and the creatures dwelling in them. But there are always surprises. Several years ago, Hau discovered hīhīwai, one of two species of native Hawaiian freshwater snails, crawling single file up the cement bottom of a channeled stream next to a West Maui grocery store. The stream is typically dry, with few rocks to shelter the hīhīwai, but there they were.

This hīhīwai, a native Hawaiian snail, clings to a rock in a Maui stream. The presence of slow-movnig hīhīwai can indicate the frequency and quantity of water needed for a healthy stream.

This hīhīwai, a native Hawaiian snail, clings to a rock in a Maui stream. The presence of slow-movnig hīhīwai can indicate the frequency and quantity of water needed for a healthy stream.

It’s amazing that Hawaii has any native freshwater species to begin with. Streams in Hawai‘i are 2,400 salty miles away from the nearest continental sources of freshwater. Yet fish, crustaceans and mollusks colonized island waterways well before the first Polynesians arrived, most evolving into species found no where else in the world. These animals have evolved to cope with intermittent stream flow and climb waterfalls. ‘Ōpae kala‘ole, an endemic crustacean, is the best climber of all, known to scale 100-foot cascades. But like other native Hawaiian plants and animals, these riparian creatures now face threats from introduced species.

Invasive armored catfish have added the eggs of the native ‘o‘opu (goby) to their diet. Guppies and mosquito fish devour Hawaiian stream dwellers’ larvae and contribute to the decline of native damselflies at low elevations. Swordtails and other non-native aquatics spread new diseases to native fish. Tilapia compete with native water birds for food and released pet turtles dine on ‘o‘opu.

‘O‘opu nōpili. Photo by Skippy Hau

‘O‘opu nōpili. Photo by Skippy Hau

‘O‘opu nākea in ‘Iao stream. Photo by Skippy Hau

‘O‘opu nākea in ‘Iao stream. Photo by Skippy Hau

‘O‘opu ‘alamo‘o. Photo by Skippy Hau

‘O‘opu ‘alamo‘o. Photo by Skippy Hau

Most of these invasive species were intentionally introduced – starting with Asian immigrants bringing in Chinese catfish, rice-paddy eels and other species for food in the 1800s. Mosquito fish, or topminnows, were released into streams from the 1900s through 1960s to control mosquitoes. This was an era when state officials frequently introduced game species, such as trout, bass and tucunare, or peacock bass, into streams. During the 1970s, managing resources for native species became more important; game fish are no longer introduced.

In the 1980s and ’90s, aquarium fish and mollusks began appearing in Hawaiian streams. In addition to guppies and swordtails, a variety of cichlids and ramshorn snails now snack on larvae of native stream animals returning to the ocean. Aquarium owners who dump unwanted pets are the most likely source of this problem, which is ongoing.

Hīhīwai, like all Hawaiian stream dwellers, are only part-time residents. They spend the first year of life in the ocean, then ascend single file into a freshwater stream. Not all make it as they colonize the stream’s upper reaches, instead becoming a source of food for other riparian species. In addition to the hīhīwai, another native mollusk, five species of fish and two crustaceans spend a part of their lives in the ocean. During rare flood events, these freshwater animals move quickly upstream for the less salty part of their lives, finding shelter in upper elevation pools.

Hau regularly monitors the slender tributary of ‘Iao where he first witnessed the climbing snails. When it exceeds a trickle, he dons a snorkel mask and peers under rocks for slow-moving hīhīwai. By carefully studying Maui’s streams, Hau has documented the frequency and volume of water necessary for our native freshwater animals need to move between ocean and stream.

These remarkable aquatic animals need our help. Don’t release unwanted pets into streams. If your fish is too large for your aquarium, contact a local pet store. They often take back fish and snails. Consider selling or gifting your unwanted fish or turtle online or to a friend.

Learn more about the fascinating animals in Hawaii’s streams and how to help protect them at hawaii.gov/dlnr/dar/streams.html.

By Lissa Fox Strohecker. Originally published in the Maui News, June 10th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
You can find all the articles in the Kia‘i Moku series
http://www.hear.org/misc/mauinews/