Review Category : Invasive Species

A Call to Arms / LFA Hui on Big Island

Hawai’i already suffers from more invasive species than any other state in the nation and remains constantly vulnerable to them due to its heavy reliance on imports.  Almost 90% of our food and a large number of plants come from the outside and provide avenues for their entry.  Once invasive species reach the Islands their impacts are often swift and severe due to our unique, fragile ecosystem.   Governor Ige recently summed up our vulnerability and the importance of immediate action in a single sentence: “Invasive species pose the single greatest threat to Hawaii’s economy and natural environment, and the health and lifestyle of Hawaii’s people.”   Despite these imminent dangers only 4% of the state budget is dedicated to addressing this paramount threat. Similarly, only a very small portion of the public is currently aware of these imminent dangers.   If the introduction of invasive species is left unchecked the consequences will be devastating, particularly in the case of the little fire ant (LFA).  Entomologists who have studied this... ...

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Report Card: Invasive Species Initiative

It’s been seven years since the industry was first introduced to the University of Hawaii Weed Risk Assessment, a tool for predicting the potential invasiveness of plants. In the beginning, the green industry struggled with the weed risk assessment, but a lot has changed since 2004. In 2006, the landscape industry started an initiative to determine which potentially invasive plants have greater risk than benefit. The initiative included broad outreach with numerous meetings on all islands including the Hawaii Island Landscape Association, Kauai Landscape Industry Council, Maui Association of Landscape Professionals, Oahu Nursery Growers Association, The Outdoor Circle, Hawaii Society of Urban Forestry, Aloha Arborist Association, Hawaii Landscape & Irrigation Contractors and the American Society of Landscape Architects. After three years of meetings and lengthy discussion, the industry came together and agreed that of the 168 plants listed as potentially invasive, that 80% would not be utilized. The Landscape Industry Council of Hawaii Invasive Species Guidelines and Invasive Plant List became on effective May 1, 2009. The list and the... ...

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Pest Roundup

Preventing new pests from entering our islands protects our environment, economy, and health, and it is a building block to a sustainable Hawaiʻi. Here are some prevention initiatives. New Pest Poster Available The landscape industry provides our state with more than 11,000 on-the-ground eyes and ears that can help protect Hawaiʻi from new pests.  To help identify some of the most unwanted landscape and nursery pests in the United States, the University of Hawaiʻi College of Tropical Agriculture and Human Resources (CTAHR) has produced a new poster.  The poster contains photos and descriptions of sixteen insect pests, their host plants, and known distribution.  Some of the featured pests include palm-killers like the red palm weevil (Rhynchophorus ferrugineus) and coconut rhinoceros beetle (Oryctes rhinoceros), and the lobate lac scale (Paratachardina pseudolobata), which officials in Florida consider one of the most devastating pests of trees and shrubs ever introduced.  New detections of these or other pests should be reported to the Hawaiʻi Department of Agriculture Pest Hotline at 643-PEST (643-7378).  For a... ...

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Featured Pest: The Spiraling Whitefly (Aleurodicus dispersus)

 Hosts: Recorded on 38 genera of plants from 27 plant families and over 100 different species. Common on vegetables, ornamental, fruit and shade tree crops in Hawaii, including avocado, banana, bird-or-paradise, breadfruit, citrus, coconut, eggplant, kamani, Indian banyan, macadamia, mango, palm, paperbark, papaya, pepper, pikake, plumeria, poinsettia, rose, sea grape, ti, and tropical almond. Distribution: Native to Central American and the Caribbean region.  First reported in Hawaii in 1978 and now present on all of the major islands. Damage:  a) Direct – damage caused by piercing and sucking of sap from foliage.  Majority of feeding done during the first three nymphal stages.  Usually insufficient to kill plants. b) Indirect – damage due to accumulated honeydew and white, waxy flocculent material.  The honeydew serves as a substrate for sooty mold, which blackens the leaf and decreases photosynthesis and plant vigor, and can cause disfigurement.  The flocculent material is spread by the wind and can create an unsightly nuisance. c) Virus transmission – damage from virus transmission can be considerable.  These viruses cause over 40... ...

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Doing Our Part To Plant Pono

It used to be that the Hawaiian ecosystems with the highest diversity of plant species were moist and wet forests.  Today, the highest plant diversity can be found in our yards and botanical gardens, and the number of plant species introduced to Hawaii grows each year.  Although the vast majority of Earth’s 250,000+ plant species would not be invasive if imported and grown in our islands, a small percentage would be superweeds that alter the ecosystem or natural resources.  Plants are not checked for their potential to become invasive when they are imported, and our noxious seed and weed rules regulate less than 100 species of plants, most of which are already present in Hawai‘i. Now, there is a new website that can help everyone make informed plant choices.  Plant Pono (www.plantpono.org) provides planting information on non-invasive ornamental plants (pono plants), to help you select the right plant for your yard.  These pono plants were selected by noted horticulturist Heidi Bornhorst, and were screened by the Hawaii-Pacific Weed Risk Assessment... ...

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Lobate Lac Scale

Hawaii Department of Agriculture (HDOA) has requested that the green waste generated from pruning or removing a Lobate Lac Scale (LLS) infested plant be left at the site where it originated to reduce the risk of spreading this pest around Oahu. For example, chipped green waste from a tree can be left as mulch under the tree that was pruned. Smaller green waste, like hibiscus branches, can be bagged in dark plastic and left in the sun in an out-of-the-way corner of the property for a few days. The heat generated in the bag will hopefully be sufficient to “cook” the LLS. Leaving any of the green waste out in the sun for a month or so would probably work as well. Unfortunately, research on the life cycle of LLS and how long the different stages last doesn’t exist, so this is just a best guess. It is certainly better than doing nothing. LLS is sufficiently established on Oahu to be impossible to eradicate, but landscape professionals are the first... ...

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