Help is on the way for Big Island ranchers fighting an invasive bug decimating pasture land in North and South Kona.
Franny Brewer of the Big Island Invasive Species Committee said the two-lined spittlebug (TLSB) could fit easily on a fingernail, looking innocuous and almost pretty with its orange-on-black stripes. But for Big Island ranchers, the sudden appearance of this insect in South Kona 2016 was anything but welcome. Since then, this tiny insect has spread prolifically, destroying more than 175,000 acres of pasture in the few short years since its arrival.
“The impact this little bug is having on pastures … is catastrophic,” said Mark Thorne, University of Hawaii Cooperative Extension Service State Range and Livestock Extension Specialist. Thorne and his team have been working since 2016 to find and track TLSB, all while searching for solutions. So far, they have found few strategies for mitigating the damage.
“We have seen the impact zone of this pest increase by about 35,000 acres per year, it’s spreading and it is very, very difficult to control,” Thorne said.
Already, affected ranchers have been forced to reduce herd sizes as the TLSB threatens Hawaii’s $65 million cattle industry. In response, the 2021 state Legislature approved $350,000 funding from the American Rescue Plan to support affected ranchers and fund ongoing research into mitigating the damage. The funds will be directed to the state Department of Agriculture to be used in responding to the invasive spittlebug.
“Hawaii’s food sustainability and resiliency depends on our ability to produce nutritious, affordable, healthy protein,” Hawaii Cattlemen’s Council Managing Director Nicole Galase said, adding that she hopes to work closely with the state Department of Agriculture to ensure the money has the greatest impact on the long-term sustainability of the ranching industry on Hawaii Island.
Keith Unger, who manages McCandless Ranch in South Kona, said the entity has yet to see the invasive bug in its pastureland.
“We’re not affected by it so far, but our next door neighbor is, so it’s just a matter of time,” he said. “It is a scary situation. The Legislature has definitely realized the potential devastation of this insect and that it could go further than just affecting the ranchers at the point that it affects watershed and erosion. If all of a sudden all these grasses disappear and you have nothing but bare ground or weeds, and all of a sudden you have flooding issues, you have soil retention issues.”
Even though the bug has been contained in the Kona region, Unger said the concern obviously is it spreading out of Kona and up into North and South Kohala, where Parker Ranch, one of the largest private owned ranches in the nation is located.
“The cattlemen there and on the other islands are definitely keeping an eye out on this and are participating in educational outreach just to make sure we can contain as best we can,” Unger said. “McCandless only has Guinea grass and akoa, and so far, spittlebug does not affect those feed sources. But anyone who has kikuyu or pangola in particular seems to be mostly affected.”
Roy Wall said Wall Ranch in Kealakekua was not so lucky.
“We started seeing the spittlebug back in 2016 around the same time that a few other Kona ranchers started seeing it,” said Wall. “By 2020, we had seen 100% of our kikuyu and pangola pastures decimated. Invasive weeds have moved in with no grass cover to hold them out.”
Wall said the ranch was forced to reduce its cow heard on those pastures by 50%.
“I feel like we are past the disaster phase and are moving in to the recovery and rebuild phase,” he said. “We have been working on trying to find resistant grasses — and some look promising — but its’ going to take years to recover. I’m hopeful that this bug will run through its initial explosion and find a balance.”
Brewer, with the Big Island Invasive Species Committee, said the team at the University of Hawaii’s College of Tropical Agriculture and Human Resources Cooperative Extension Service, CTAHR-CES, has been testing some TLSB-resistant grasses that could be used to reseed pastures. However, unlike the broad open plains where these grasses have been successfully deployed in North America and Brazil, Hawaii pastures range over thousands of feet in elevation and multiple climactic zones, all over diverse substrates, including lava rock, that make reseeding difficult.
“No single grass can solve the problem,” said Carolyn Wong Auweloa, USDA Natural Resources Conservation Service State Rangeland Management Specialist.
More research is crucial, she insisted, to help ranch lands recover. She pointed out that TLSB has completely killed forage in the heavily infested areas, effectively reducing productivity to zero and leaving behind a desolate swath that quickly fills in with invasive, toxic, and unpalatable weeds that in turn threaten the native forests that border the pastures.
“These grazing lands will not recover their productive potential without significant inputs to suppress weeds and attempt to re-establish forage species that can withstand the bug,” Auweloa said. “A lot of people don’t realize the important role ranchers play in maintaining the health of our watersheds.”
According to the state Department of Agriculture’s Statewide Agricultural Land Use Baseline study, grazing lands occupy over 760,000 acres in Hawaii.
“Healthy grazing lands have healthy, deeply rooted plant communities that cover the soil and help rainwater infiltrate to recharge our aquifers,” Auweloa said. “The funding from the Legislature will help to make these lands productive again, so they can continue to provide valuable ecosystem and social services, while feeding our livestock, our people and our economy.”
McCandless Ranch’s Unger said the help from the department is appreciated, but biosecurity at airports and ports needs to be beefed up because it’s becoming “one infestation after another.”
“We can and should spend more money at out ports and airports to stop these (invasives) from coming in,” he said. “Here we are, now spending hundreds of thousands and into the millions fighting on the back end. If you are going to talk about more ag sustainability you are right back to biosecurity for the State of Hawaii. Hopefully we can kickstart it again.”
Big Island residents are being asked to be alert about their lawns and pastures.
Patches of dead grass that cannot be explained by other environmental factors should be reported right away to the state by visiting www.643Pest.org, calling (808) 643-PEST (7378) or using the 643-PEST mobile application for iOS and Android. Residents must also practice extreme caution in not transporting the insect out of its known infestation area.
A short documentary aimed at highlighting the plight of the ranchers and the impacts of TLSB in the hopes of raising awareness about the extreme threat to Hawaii’s agriculture can be found at www.biisc.org/tlsb.
“This infestation is by far the worst thing I’ve seen in my 40-plus years of ranching in Kona but I’m confident that we will find a way to survive,” said Wall.