Invasive Species - What's New on NISIC's Site

Potatoes and oak trees don’t have a lot in common, but there is one thing, and it isn’t good – a fungal-like plant pathogen in the genus Phytophthora. One of the many invasive pathogens contained in this genus, P. infestans, was responsible for the Irish potato famine. Since the mid-1990s, though, Phytophthora has been attacking forest trees along the West Coast, with the pathogen P. ramorum, also known as "sudden oak death" (SOD). SOD was first detected in the San Francisco Bay Area; it has since spread throughout California. In 2001, SOD was discovered in southwest Oregon where it infected tanoaks trees. The discovery led to the formation of an interagency team that included researchers from the Agricultural Research Service (ARS) and Oregon State University (OSU), to develop strategies to mitigate the impacts of SOD.

The U.S. Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) announced today an investment of nearly $11 million for research to combat Huanglongbing (HLB), commonly known as citrus greening disease. HLB, caused by an insect bacterium, is the most severe threat to global citrus production.

The PA Department of Agriculture added Japanese Barberry, or Berberis thunbergii, to a list of noxious weeds — plants that cannot be legally sold or cultivated in the state. The popular, non-native, ornamental shrub forms dense, prickly thickets that crowd out plants and disrupt native ecosystems. It is also thought to harbor black-legged ticks that spread lyme disease. The ban on sale and cultivation took effect October 8, 2021. Enforcement of the ban will be phased in over two years to allow time for nurseries to eliminate it from their stock, find non-harmful alternatives, and develop seedless, sterile varieties that pose less threat to the environment and agriculture. Landscape and nursery businesses will receive notices of the timeline, procedures and exemption process for sterile varieties. Property owners should consider eliminating the shrubs on their land.

Effective October 8, 2021, the department added two other plants to the noxious weed list: garlic mustard, Alliaria petiolata, and Japanese stiltgrass, Microstegium vimineum. These plants are generally not sold in nurseries but are invasive and common in Pennsylvania. Landowners with these plants on their property are encouraged to remove them.

Native to Europe, Yellow toadflax and Dalmatian toadflax can typically be found on roadsides, grasslands and in crop fields. Like many other weeds, toadflaxes have been introduced to North America as decorative plants but they are now having adverse effects. Whilst these weeds may look pretty and provide decorative appeal, they soon escape cultivation and can cause some serious problems. As part of a new CABI Podcast series, CABI experts Dr Hariet Hinz and Dr Ivan Toševski were interviewed from CABI in Switzerland, who explained to us what measures they are taking to control the spread of toadflax.

New Zealand Parliamentary Commissioner for the Environment, Simon Upton, is calling for the Government to lift its game in protecting native ecosystems from the thousands of exotic plants spreading throughout Aotearoa New Zealand. “Rampaging weeds pose a deadly threat to our native ecosystems by smothering, outcompeting and preventing regeneration of native plants,” the Commissioner says in a report released today. The report, Space invaders: A review of how New Zealand manages weeds that threaten native ecosystems, explains that protecting our native ecosystems from being overrun by weeds not only helps our native taonga plants, but also saves crucial habitat our taonga fauna need to survive.

Invasive species cause biodiversity loss and about $120 billion in annual damages in the U.S. alone. Despite plentiful evidence showing that invasive species can change food webs, how invaders disrupt food webs and native species through time has remained unclear. Now, thanks to a collaborative study conducted by researchers representing the University of Montana's Flathead Lake Biological Station (FLBS), U.S. Geological Survey (USGS), and Montana Fish, Wildlife & Parks, there is new insight into how invasive species progressively affect native food webs.

Argentine black and white tegus have spread and established populations in and around Florida at a rapid and growing rate demonstrating critical implications for native wildlife, numerous natural areas, and even restoration efforts for Everglades National Park. UF scientists at the Institute of Food and Agricultural Sciences (UF/IFAS) and partnering agencies have co-authored the “Growth and Spread of the Argentine Black and White Tegu Population in Florida” illustrating the depth and breadth of the tegu problem. The comprehensive fact sheet details the invasion of the species, the tegu population’s increase, impacts for wildlife and natural areas at stake, interagency goals and efforts to reduce the threat, and the implications of species expansion.

CABI has highlighted the top 20 crop pests and diseases for possible prioritization in the Eastern Caribbean as part of a special presentation given to the Caribbean Plant Health Directors Forum (CPHD) aimed at strengthening food security in the region and further afield. Dr Yelitza Colmenarez, CABI’s Centre Director, Brazil, told the conference of CPHD – with the participation of key partners including the FAO, IICA, OIRSA, USDA-APHIS, CIRAD, CARDI, CAHFSA and CABI Member Countries from the Caribbean – that the introduction of new pest and pathogen species are a serious threat to food security within the Organisation of Eastern Caribbean States (OECS) and globally. With the help of a range of CABI tools and platforms, including the Crop Protection Compendium, Invasive Species Compendium, Horizon Scanning Tool and Pest Risk Analysis Tool, Dr. Colmenarez says 20 key insects, bacteria, fungus and viruses pose a particular threat that needs to be identified, monitored and mitigated.

A tiny wasp may be the solution for managing an agricultural pest causing major economic damage to fruit, vegetable, and field crops in North America and Europe. Agricultural Research Service (ARS) scientists are currently studying Trissolcus japonicus, commonly known as the samurai wasp, to see if this parasitoid wasp is the right biological control agent for reducing brown marmorated stink bug (Halyomorpha halys) (BMSB) populations outside of Asia. Biological control is the process of reducing or mitigating pests or pathogens by using the pest’s or pathogen’s natural enemies. The samurai wasp is a known natural enemy for the BMSB in Asia, and researchers are understanding how it behaves in non-native environments.

The U.S. Department of the Interior's Office of Insular Affairs (OIA) has announced $4,095,922 million in Brown Tree Snake Control program fiscal year (FY) 2021 funding as administered through the Technical Assistance Program. An additional amount of $1,791,421 from Coral Reef and Natural Resources FY 2021 funds was also announced earlier this year for the purpose of controlling and mitigating other invasive species in the Insular Areas besides the brown tree snake. "Islands are particularly vulnerable to invasive species that disrupt natural, long-standing biological processes and threaten our unique, island eco-systems," said Deputy Assistant Secretary Keone Nakoa. "Each year, OIA provides significant funds to critical efforts seeking to help restore balance."

The Brown Tree Snake Control program FY 2021 funding was divided among several governments and federal partners to include Guam, the Commonwealth of the Northern Mariana Islands (CNMI), Hawai'i, U.S. Department of Agriculture (USDA), and the Department of the Interior. For more information about OIA funds provided to counter invasive species visit: https://www.doi.gov/oia/coral-reef-and-natural-resources-initiative.