While decorating for the holidays, take care not to ‘deck the halls’ with uninvited guests. Non-native and invasive species of insects, invert. eggs, fungi, and plants have been found in Christmas trees, holiday wreaths, and other natural decorations.

Invasive spongy moths (Lymantria dispar) and spotted lanternflies (Lycorma delicatula) often lay their eggs on tree bark and can survive indoors for weeks. Egg masses are well camouflaged, making them difficult to detect. Spongy moth egg masses are tan and felt-like, while spotted lanternfly masses are grey-brown and mud-like. The egg masses of both hatch in the spring. Spongy moth larvae feed on tree leaves and can defoliate entire forests, while spotted lanternfly nymphs target soft fruit trees and grapevines, causing significant agricultural damage.

Wreaths, garland, and other holiday decorations made from natural materials can contain plants that outcompete native species, reduce biodiversity, and disrupt local wildlife habitats. English holly (Ilex aquifolium), common buckthorn (Rhamnus cathartica), and English ivy (Hedera helix) are some of the more common invasives reportedly found. As an alternative, try decorating with native plants such as winterberry holly, native pines, or cedar.

Be especially vigilant when cleaning up after the holidays and disposing of wreaths, garlands, and Christmas trees. Experts suggest placing natural decor in the garbage, not the compost, to prevent the spread of invasive species. Experts recommend inspecting trees for egg masses before disposal. If any of these invasive species are observed, please report it HERE according to the instructions provided or contact invasives@shsu.edu.

These are just a few invasive species that can hitch a ride on holiday décor. Please take care to ensure holiday decorations don't unintentionally harm the environment. Happy Holidays!

Paradoxical Conundrum

Invasive species are typically seen as a threat to native ecosystems. However, some may also play a crucial role in the survival of their own kind. This reasoning has created a paradox for conservation researchers. While many invasive species threaten local wildlife, some are endangered in their native habitats and may thrive in their new environments. This raises critical questions about how to manage species that are both invasive and endangered.

Currently, 242 mammal species found worldwide are listed as invasive. Of these, 15% are on the IUCN Red List as critically endangered in their native habitats. Primates, artiodactyls, and other mammals face extinction due to habitat loss, overhunting, and climate change. However, these same species have found stable populations in new territories where they are considered non-native or invasive. For example, the crested macaque (Macaca nigra) is critically endangered on its native island of Sulawesi but has thriving populations in other parts of Indonesia, and the wild rabbit (Oryctolagus cuniculus) is endangered in Europe but has become widespread in Australia.

A recent study found that eight of the 36 species have improved in conservation status due to the presence of non-native populations. The research suggests that these "exotic" populations should be considered during endangered species management planning to help conserve the species globally.

The study found that including non-native populations in conservation assessments could reduce global extinction risk for 22% of the species analyzed. Unfortunately, the dilemma remains that invasive species can harm local ecosystems by outcompeting native species and spreading diseases. The challenge will be finding a balance. As the globalization of species continues, conservation efforts must carefully weigh the benefits of protecting non-native populations with the need to safeguard native habitats.

Read the Research: Tedeschi et al., 2024

Crab Smorgasbord, Otters Welcome

Sea otters are small mammals known for floating on their back and using rocks as tools. They have loose skin under their forearm that is used like a pouch to store food and tools. Otters will hold hands and form ‘rafts’ to prevent drifting apart from one another. On top of that, they could also be key players in maintaining a healthy coastal ecosystem.

A recent study showed how the recovery of the southern sea otter (Enhydra lutris nereis) population in Elkhorn Slough National Estuarine Research Reserve, CA, is benefiting the local environment by controlling invasive species. These otters are having a particular impact on invasive green crab (Carcinus maenas).

Green crabs were first reported in the reserve in 1994 and reached a peak population in 2000. These opportunistic feeders’ prey on native crabs, fish, and commercially valuable species, such as oysters. Since 2000, green crab numbers have significantly declined, coinciding with the recovery of the southern sea otter population.

The research highlights the importance of apex predators to maintain ecological balance. Sea otters can consume approximately 328 green crabs per day or up to 120,000 per year. Elkhorn Slough Reserve is the only estuary in California where otters have successfully re-established significant populations. By feeding on the invasive crabs, otters provide a natural and effective form of pest control in this coastal habitat. Their presence has contributed to the decline of invasive green crabs and helped restore natural food webs.

Invasive species can be hard to manage once introduced but this example shows how restoring endangered species can have wide-ranging environmental benefits.

Read the Research: Jeppesen et al., 2024

Don’t Mess With Texas Citrus

TISI is offering FREE diagnostic services if you suspect your citrus has either the psyllid pest or the Citrus Greening pathogen, or you would like your citrus plants to be part of our screening survey.

The Asian citrus psyllid (Diaphorina citri) and the Citrus Greening pathogen (Candidatus Liberibacter asiaticus) are threatening citrus in multiple Texas counties. By taking samples and monitoring the spread, it is easier to ensure that you and your neighbors are not affected. This pest and pathogen are extremely detrimental to Texas citrus, both economically and agriculturally. The presence of either can greatly affect citrus yield.

If you are interested in having your citrus trees checked or being part of the survey, please contact invasives@shsu.edu. If you are located within 200 miles of our headquarters, we can collect samples and/or provide traps and monitoring services. Otherwise, we will send you easy step-by-step instructions so you can do it yourself. Not only will we share the results and management strategies (where applicable), but you will become part of a multi-county monitoring survey that strives to improve the health of Texas citrus!

Also Available: TISI offers educational workshops that highlight information about the Asian citrus psyllid, the pathogen Citrus Greening, and what you need to look out for in your own backyard. If you are interested in this, TISI will provide trapping materials, assist with management strategies, and more. Don’t waste another second- Help us stop the spread!

This program is designed to provide the education needed for professionals and students who are managing or learning to manage invasive species. The courses include the most current invasive species identification, control, and management techniques, and how to comply with local and federal regulations.

Participants may register and enroll at any time, and will receive a certificate of invasive species management from NAISMA upon completion of the program.

All live webinars are open to the public. Recorded webinars are available to members of NAISMA.

NAISMA 2025 Webinar Schedule:

• January 15, 1pm CST- Progress Towards a Model Legal Package for NAISMA’s Weed Free Products Program. REGISTER.

Join the Mitchell Lake Audubon Center and community volunteers to clean up the local habitat and make a difference for native birds. These workdays typically involve trail maintenance, removal of invasive species, and/or planting native plants for birds and butterflies depending on the workday task and schedule. All training provided. Children under 18 must be accompanied by an adult. Registration is Free and eligible to anyone interested in participating. Please dress appropriately for outdoor/yard work.

Date: Saturday, January 11, 2025
Time: 8:00am-10:00am (Central)
Location: Mitchell Lake Audubon Center, 10750 Pleasanton Road, San Antonio, 7822, TX

Register HERE.
For more information, click HERE.

An auspicious seasonal sensation is upon us! After three years without any confirmed sightings, the Washington State Department of Agriculture (WSDA) and the U.S. Department of Agriculture (USDA) have officially declared the northern giant hornet (Vespa mandarinia) eradicated from Washington and the United States.

This achievement follows a multi-year effort, starting in 2019, involving the collaboration between state, federal, and international agencies, as well as vital public support. Although this hornet can pose a serious threat to native insects and human health, the major concern was its potential to decimate entire bee colonies. While the hornet has been eradicated, WSDA continues to monitor for any reemergence, especially after a suspicious sighting in Kitsap County in October 2024 (which remains unconfirmed). The successful eradication highlights the power of community engagement, cooperative efforts, and quick response when combating invasive species introduction.

Official Report.

Invasive Spotlight:

Crested Floating Heart
(Nymphoides cristata)

The crested floating heart (Nymphoides cristata) is a freshwater floating perennial. It has stolons (runners) that root firmly into the substrate under water. However, it can free float temporarily. The leaves are somewhat heart-shaped with a purplish underside, and form at the end of a long floating stem. Most of the leaves will float, but some will remain submerged. The leaf margins are often tinged red. This invasive aquatic is most easily recognized by its characteristic flowers. Tall stalks emerge above the water to produce small (1-2 cm) white flowers with 5 petals. Each petal has a fringed edge and a ruffled “crest” of petal tissue along the midvein of the upper surface. When it's not flowering, it can be identified by the clusters of tuberous propagules (bud-like structure) that dangle from the node where the stem connects to the leaf.

The crested floating heart was originally introduced as an ornamental plant for water gardens and subsequently escaped to rivers, lakes, canals, and other waterways. The floating heart is most often found in slow-moving, still, or shallow bodies of freshwater. It is still widely available from on-line sellers, despite being highly invasive and is often sold under different names. Control is difficult once established because crested floating hearts grow rapidly. This plant reproduces vegetatively from tubers (or ramets), daughter plants, rhizomes, and fragmentation. Mats can quickly cover the water’s surface, shade out other aquatic plants and algae, and disrupt the entire food web. Dense mats can also impede water flow and reduce dissolved oxygen/water quality in the water column beneath the mat. It is resistant to most herbicides, while others only offer temporary control. Any attempt at physical or mechanical control comes with the risk of leaving broken fragments behind to root. Fragments, ramets, and rhizomes are commonly spread by watercrafts, resulting in new introductions elsewhere. The best control method for controlling crested floating heart is preventing infestation in the first place. Water recreationists should clean, drain and dry their boats, trailers, and equipment to prevent spreading this highly invasive species.

The crested floating heart is listed as a TPWD Prohibited Exotic Species. For more information, view the TexasInvasives Info Page HERE. The crested floating heart is often mistaken for another aquatic invasive, known as the yellow floating heart ( N. peltate). This lookalike is also invasive plant. If you believe you have identified a patch of either aquatic plant, please take a picture and REPORT IT! to invasive@shsu.edu. Submissions are appreciated, and we truly value your efforts and support.

Enjoy monthly videos about invasive species and/or people willing to teach us more about them. There are some amazing citizens and professionals around the world that poke, prod, chase, dive, and investigate everything they can about these alien invaders. Jump into this cinematic rabbit hole. You never know what new wonders you may discover.

Fungi and Invasive Plants: SciShow Talk Show. SciShow.

Soil ecologist Dr. Ylva Lekberg explains the connection between microscopic fungi and invasive plants, and Jessi from Animal Wonders introduces us to Sydney the woylie.

Restore: Researching Invasive Species. Loyola University Chicago.

It is important to understand the impacts that surround invasive species and the impacts they can have. One researcher speaks to what his current research entails, why these species are such a big issue, and the passion that motivates him.

True Facts Video: Invasive Yellow Starthistle. Samantha Cortes.

Yellow star thistle (Centaurea solstitialis) is an invasive flower along the western cost of the U.S. and in scattered parts of Texas. it is toxic to horses and harmful to the environment. You don’t have to be an expert to make a difference. If you see this angry yellow flower- pull it.

Stop Spiny Water Fleas. Minnesota Aquatic Invasive Species Research Center.

Spiny water fleas are a tiny freshwater zooplankton that invade lakes and can take over the bottom of the food chain, disturbing the ecology of the food web and presenting a serious potential threat. How are the spread and what else can we learn about them?

Invasive Rodents from South America Spread Further in Houston Communities
Invasive nutria (Myocastor coypus) are on the move. Increased reports and sightings suggest a growing presence of the semi-aquatic, beaver-like rodent in south Texas. chron.com

Uncovering Patterns in The Spread of Invasive Animals and Plants in South Florida
South Florida is a hotspot for invasive species, with non-native plants and animals thriving in both urban areas and natural habitats. Researchers are working to uncover patterns in how these species spread, aiming to protect native ecosystems. phys.org

USGS: Hurricanes Potentially Spread More Than 200 Invasive Species in Southeast
Florida and neighboring states continue recovery efforts after Hurricanes Helene and Milton. Unfortunately, these storms spread more than disaster. Scientists are racing to understand how storm-related flooding spreads invasive species and reshape ecosystems. thecentersquare.com

Spotted Lanternflies in The US Are Living Longer—And Cities May Be Helping Them Spread
Invasive spotted lanternflies (Lycorma delicatula) are extending their active period each year, a trend linked to warmer urban climates and the urban heat island effect. A study using citizen-science data highlights how cities can serve as early-detection zones for monitoring and mitigating the spread of invasive species. phys.org

Yet Another Invasive Tree-Killing Beetle Found in Felton Area in Santa Cruz County
A new invasive beetle, known as Euwallacea interjectus, has been identified in Santa Cruz County. This is the first it has been reported in California. The beetle targets various tree species, introduces harmful fungi, and is a potential threat to local ecosystems. localnewsmatters.org

Research Reveals an Inexpensive Fix for California's Struggling Wildflowers
A recent study reveals that raking dead, invasive grass layers can increase native wildflower diversity while also reducing fire risk. This simple, low-cost method offers a practical approach to restoring ecosystems and improves germination. phys.org

Mapping Hotspots of First Detections of Non-Native Species
USGS researchers have developed a novel approach for predicting where new invasive species are likely to first establish. This is done by analyzing the collections of first recorded species sightings. usgs.gov

Fighting Plants with Plants – On Land and Under Water
The Chautauqua Watershed Conservancy, NY, is exploring innovative ways to combat invasive species by replacing them with native plants, both on land and underwater. The initiation of multiple pilot projects aims to restore the ecological balance and prevent invasive species from recolonizing treated areas. post-journal.com

Cold Storage And CO₂ Extend Life of Asian Hornet Baits for Battling Invasive Species
Researchers have developed a method to extend the shelf life of protein baits used to control invasive Asian hornets (Vespa velutina). By optimizing storage conditions with freezing and CO2, the baits remain viable longer, offering critical support to beekeepers and manufacturers. phys.org

Study Shows Action to Eradicate Pollinator Predator Yellow-Legged (Asian) Hornets in UK Has Been Effective
A recent study highlights how swift action and public vigilance have prevented the establishment of the invasive yellow-legged hornet (Vespa velutina nigrithorax) in the UK. This collaborative effort underscores the importance of citizen science and rapid eradication in mitigating the threat to pollinators and ecosystems. phys.org

Invaders of Texas workshops train volunteers to detect and report invasive species as citizen scientists. Workshops, which are free, are designed to introduce participants to invasive species and the problems they cause, cover aspects of invasive species management, teach identification of local invasive plants, and train participants to report invasive plants using the TX Invaders mobile application. The workshop is 7 hours long (usually on a Saturday, but scheduling is arranged with each individual host group). The workshop satisfies Master Naturalist training requirements.

Sentinel Pest Network workshops serve to increase the awareness and early detection of a set of particularly important invasive species to help prevent their spread into Texas or their further spread within Texas. Participants learn to identify species such as the Emerald Ash Borer, Cactus Moth, Asian Longhorned Beetle, and other pests of regulatory significance, and to report them. The workshop is 3.5 hours long. The workshop satisfies Master Naturalist training requirements.