by the Dept. of Plant and Environmental Protection Sciences
The most recent example of an invasive threat to our agriculture, urban and natural ecosystems is the Ramie Moth. Last month, the presence of Arcte coerula was confirmed on the east side of the Big Island attacking mamaki, traditional medicinal plants that are endemic to the Hawaiian islands. They’re also indirectly threatening the endemic Kamehameha butterfly by competing for the same native host plant resources.
What gets less media attention is the Dept. of Plant and Environmental Protection Sciences, whose researchers and Extension specialists and agents are constantly at the frontlines of pest management, using the latest basic and applied research to protect our ecosystems from these invaders.
In 2018, when the Ramie Moth was first spotted on Maui, PEPS was there with molecular tools to confirm it. Now, PEPS is surveying the moth’s distribution in Hawaiʻi, and searching for potential natural enemies.
Diseases and Damaging Insects
It’s important to note, many invasive species are STILL in Hawaiʻi, still threatening our food supply and way of life – even if you haven’t read or heard about them recently. The following is just a fraction of PEPS’ efforts to eradicate or mitigate the dangers:
Coconut Rhinoceros Beetles: Since 2013, PEPS’ Agrosecurity and Turf and Landscape Pest Management Labs have coordinated a large, multi-agency response against the spread of CRB. These efforts have largely contained the CRB population on Oʻahu, allowing Hawaiʻi’s palm to continue to thrive. Modern genomic techniques (ddRADseq) were used by PEPS’ Insect Systematics and Biodiversity Lab to trace the regional invasion pathways of CRB.
Coffee Leaf Rust: PEPS is engaged in the state response to CLR, a major threat to the Hawaiʻi coffee industry. PEPS’ Agrosecurity Lab performed the initial diagnostic assays of CLR last October, and is now assisting in the Section 18 Emergency Exemption of a pesticide to manage this pathogen. We obtained a Controlled Import Permit to introduce (under quarantine) varieties with potential resistance to CLR from Central America, are performing molecular characterization of CLR isolates from Hawaiʻi to develop future management approaches, and conducting efficacy and residue trials to provide the required data for new pesticides registration in Hawaiʻi that will protect specialty crops, including coffee.
Meanwhile, we are investigating the potential of parasitoids, insect pathogens, and repellent pheromones to manage coffee berry borer, another invasive species of coffee that can damage >80% of coffee production. The success of these efforts should provide an economical and sustainable alternative to the costly insect-pathogenic fungus applications that currently require intense federal subsidies to keep our state’s coffee industry afloat.
Fruit Fly: Hawaiʻi is under a full federal fruit fly quarantine, which has restricted our fruits from being exported to the Mainland. We’re searching for insecticides, biological control agents, and pheromone traps to overcome pesticide-resistant populations. Along with developing new early detection tools, we are collaborating with the federal Dept. of Agriculture on male annihilation and sterile insect techniques.
Many, Many More: Invasive species management efforts led by PEPS – and of high significance to Hawaiʻi – include citrus leprosis eradication, resistance against basil downy mildew, Phytophthora blight of papaya, black pod rot of cacao, avocado root rot, banana Fusarium wilt, chemical treatments of quarantine nematode-burrowing nematode on anthurium, coffee root-knot nematode, leaf-roller moths threatening native forest plants (like koa, mamaki and maʻo), bark beetle associated with rapid ʻohia death, Macadamia felted coccid and two-lined spittlebug on pasture, avocado lace bug management for organic farmers, and invasive thrips and other quarantine pests on the floriculture and foliage nursery industry, particularly anthuriums and dendrobiums.
Besides the agro- and natural ecosystems, PEPS is evaluating low-risk pesticides against ficus stem and leaf gall wasps, lobate lac scale, hala scale, oriental flower beetle, rover ant, foliar nematode, root-knot nematode, plumeria rust, mini-ring and take-all disease of turf – all of which are hampering the landscape and turf industry in Hawaiʻi. We are developing environmentally friendly gel bait systems to control invasive ants in urban settings, as well as collaborating with the Hawaiʻi Invasive Species Council to improve surveillance efficiency of invasive mosquitoes at ports of entry, using innovative traps.
Our work might never be done, especially as new invasive species continue to pop up, but PEPS is protecting the state from the invasion of pests and diseases. What’s more, we’re teaching the next generation of scientists or workers to protect our shores.
For more information about our contribution to Invasive Species Management, please visit the Dept. of Plant and Environmental Protection Sciences.