Last fall, the laurel wilt pathogen, Raffaelea lauricola, was found in trees in the Kingwood area of Harris County. In total, the pathogen has been found in 14 East Texas counties. It is spreading quickly, and experts expect to see it spread through the population of red bay trees in East Texas and down along the Gulf Coast if something isn’t done. As red bay trees are a common and prized shade tree in urban communities, many residential areas are expected to be affected. The laurel wilt pathogen has been spreading across the southern U.S. since its introduction in Georgia in 2004, and spreading through Texas since 2013. It affects any trees in the family Lauraceae, including red bay (Persea borbonia), silk bay (P. borbonia var. humbles), swamp bay (P. palustris), sassafras (Sassafras album), and avocado (P. americana). The pathogen has also been recovered in the southeastern U.S. from diseased pond berry (Lindera melissifolia), camphor tree (Cinnamomum camphora), and pond spice (Litsea aestivates) trees. In Texas, red bay and sassafras are the most at risk.

Laurel wilt is a virulent disease that colonizes in the water- conducting vessels of the tree’s vascular system (xylem). It is spread by invasive redbay ambrosia beetles (Xyleborus glabratus) or through the root system of an infected tree. The rapid spread is mainly due to the ambrosia beetle, which can carry the pathogen from a diseased tree to a healthy tree across considerable distance. Female beetles carrying the fungus will bore tunnels into healthy trees and lay eggs. As the eggs hatch, the juveniles feed on the pathogen as it grows in the original tunnels. They then emerge as adults to visit new trees, spreading the pathogen and repeating the process. An infected tree can become overwhelmed by the population of an invasive beetle infestation and eventually die. Diseased trees will display distinctive streaking in the sapwood, small holes in the bark from the boring beetles, and patches of yellow to brown leaves along the crown of the tree.

To bring more attention to the growing problem, forest service and agricultural experts are developing an educational program on laurel wilt to be held mid-June in the Houston area (additional information TBA).

If you believe you have a tree, or trees, on your property dying of laurel wilt, it is best to consult an International Society of Arboriculture certified arborist to assess the tree and determine if it is laurel wilt, before removing any trees.

The growing trade in cultivated plants and potting soil has been linked to the dispersal of many invasive species. However, the unintentional spread of seeds via human transport is often under evaluated, especially seeds transported in soil. A recent study was conducted to evaluate the seed count in your typical potted soil and horticultural substrates, and how this might be influencing accidental invasive species introduction.

Potting soils are usually imported from distant countries and the growth mediums are generally cultivated in very large quantities. The impact of this dispersal pathway requires further investigation. Researchers bought bags of potting soil from garden centers, counted the seeds that were found within, and identified them. They also calculated the greatest distance each species may have been dispersed. They found that one liter of potting soil contains an average of 13 seeds of 6 different species. An average 20-liter bag of soil could contain around 265 viable seeds. Although soil content varied between the different types of potting soil, those that contained manure contained a significantly higher number of seeds and species than those without. In nature, seeds are typically dispersed via the wind or transported in the fur or fecal matter of animals. Wild herbivores, grazing livestock, and fruit-eating wildlife spread the seeds which ensures the survival of a diverse and thriving ecosystem. This is the likeliest explanation for why soil that contained manure also contained more seeds.

In the study, five of the species found where not native to the area. Four of these were already widespread and problematic in the country, however, many native species where also found. Many of the natives found are sparse in the area, suggesting that spread of these species through potting soil could be beneficial. The researchers concluded that the global plant and soil trade could represent a general dispersal of both native and alien species and result in both adverse and favorable effects. It may help gene flow between otherwise isolated populations, shifting ranges, landscapes effected by changing climate, and “other large-scale ecological processes of great conservation concern”.

Read the research: Sonkoly et al., 2022

In estuaries, changes in salinity and water temperature strongly influence the distribution of invertebrate species, including mussels, crabs, and sea squirts. These gradients can be abrupt and are vulnerable to environmental fluctuations like climate change and invasive species introduction. Conditions of low salinity and high temperature, which typically increase as you move inland from the ocean, can cause stress for many marine organisms. Increased stress causes native predators to consume less prey. This is normal for a healthy estuary. A recent study found that the invasive species, as well as climate change, is affecting the natural stress balance. Non-native predators tend to be more stress tolerant compared to natives. This allows non-native species to out compete or consume natives easily, altering the “predator-prey landscape”, creating “novel matchups”, and increasing the level of vulnerability faced by native species that are already dealing with stressful situations.

For this study, researchers focused on sessile invertebrates (animals without backbones that attach to reefs or seagrasses, such as bryozoans). They placed PVC plates with different caging treatments at different locations to evaluate the percent coverage and rate of predation. They found that the effect of predation varied by site, but many sites experienced a large reduction predation abundance and prey species richness, likely caused by the presence of non-native prey and predators in these areas.

Changes in estuaries are hard to predict, but researchers expect to see an increased decline in native estuary species as climate changes provide invasive and non-native species with an advantage.

Read the research: Rubinoff and Grosholz, 2022

EAB Confirmed in Dallas

The invasive emerald ash borer (EAB, Agrilus planipennis) is now confirmed to be in Dallas County, according to the Texas A&M Forest Service. The forest service collected an adult beetle in the Carrollton-Coppell area. It was positively identified and confirmed as an emerald ash borer by the USDA. Additional adult EAB beetles were trapped in other areas of central and southern areas of Dallas County.

Dallas County will be added to the list of Texas jurisdictions under quarantine by the Texas Department of Agriculture (TDA). This small iridescent green beetle has been causing problems for over 30 U.S. states and parts of Canada. The beetle bores its way into the bark of the tree and lays eggs. Larvae feed on the phloem and outer sapwood of ash trees, which leads to tree death. TDA quarantines help slow the spread of the insect by limiting the transportation of ash wood, wood waste and hardwood firewood.

Click HERE to read more about EAB and the symptoms of infestation.

Agriculture specialists with U.S. Customs and Border Protection discovered a rare leaf beetle pest at the Pharr International Bridge, near the South Texas Border. The pest was discovered during a routine inspection of fresh fruit that arrived from Mexico. The beetle was identified as Cochabamba sp. This is the first time this pest has been reported in the U.S. Members of Cochabamba are typically found in Central and South America, but they would be agriculturally and economically detrimental to several host plants if introduced. The larvae skeletonize leaves, and adult beetles eat parts of the plant and leaves causing extensive damage. The crate of fruit was refused entry and returned to Mexico.

The Texas Invasive Species Institute (TISI) and The Texas Research Institute for Environmental Studies (TRIES) has many surveys and projects underway. These facilities strive to provide yearly invasive species presence and absence data to the authorities. Pre-screening is one of the first lines of defense in the war against invasives, however, sometimes it is hard to do it alone.

With the aid of the public and citizen scientist, we could cover a much wider area, and gather more substantial amounts of data. When it comes to protecting our environment, there is an opportunity for everyone! Together we can make a difference, one research project at a time.

Check out all the Participation Opportunities HERE.

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 2020 Webinar Schedule:

• June 15, 1pm- Spotted Lanternfly Ecology and Biocontrol Efforts. REGISTER.
• July 20, 1pm- “Jumping Worms:” What We Know Now. REGISTER.
• August 17, 1pm- How to get your project funded. REGISTER.

The fourth annual Play Clean Go Awareness Week is fast approaching. Play Clean Go is designed for outdoor educators, recreation leaders, and other environmental professionals who work with the public all across North America. By using a consistent message across the continent, we can work together to spread awareness about invasive species prevention. The goal of the campaign is to show outdoor enthusiasts how to stop spreading invasive plants and pests while enjoying the great outdoors. In your outreach, use the hashtag #PlayCleanGoWeek and encourage outdoor enthusiasts to demonstrate how they “PlayCleanGo.”

Free materials are available online to help spread the word and “Stop Invasive Species In Your Tracks”. Check out the Awareness Week Toolkit, the basic prevention infographics, the social media “share Cards’, and more HERE.

June 4-11, 2022

Play Clean Go focuses on 6 simple tips for invasive species prevention:

1. Clean your shoes, clothes, packs, and pets before and after exploring, and stay on designated trails.
2. Clean your horse’s hooves and feed them weed-free certified hay before your adventure.
3. Clean, Drain, and Dry your watercraft and angling equipment to Stop Aquatic Hitchhikers!
4. Don’t Move Firewood! Buy it where you burn it, buy certified heat-treated firewood, or gather on site when permitted.
5. Before traveling to new areas, inspect and clean your trailers, off-road vehicles, and recreational vehicles with water or compressed air to remove mud, plant parts, and hidden pests.
6. Take the PlayCleanGo Pledge and invite your family and friends to do the same at PlayCleanGo.org.

Are invasive plants taking over your landscape? Find out how you can take control with this FREE webinar. Vicki Sawicki of North Country CISMA and Elise Desjarlais of Lake to Lake CISMA will share identification tips and demonstrate treatment tricks for common invasives including garlic mustard, Japanese knotweed and several invasive shrubs. Learn the importance of monitoring, treatment and restoring beneficial vegetation after invasive species removal, and how to get additional resources from your local cooperative invasive species management area.

June 27, 2022, 8:00 - 9:00 am

Register HERE!

Invasive Spotlight:

Quilted Melania
(Tarebia granifera)

The quilted melania (Tarebia granifera) is a freshwater snail with an operculum ranging in size from 6-40mm, and an average of 25mm. An operculum is a cover for the shell’s opening when the soft parts of the animal are retracted. The shell is elongated and spiraled with several rows of beads which gives it a "quilted" appearance. There are two typical shell colorations seen in this species. The first is a light brown body whorl and a dark spire, often flecked with reddish-brown spots. The second coloration is entirely dark brown to almost black. The shell has between 7-11 whorls at adulthood. Maturity is reached approximately 122 days after birth. These snails prefer a variety of freshwater systems, including fast, medium, and slow-moving streams of a depth no greater than 4 inches. These snails are parthenogenic, meaning only a single female is necessary for reproduction. Females are oviparious (eggs hatch internally), and juveniles exit into the environment through the egg pore. This can lead to greater fecundity and an increase in population size with few founding individuals, allowing a single snail to quickly populate a pond with her offspring.

The quilted melania out-compete indigenous snails and migrate rapidly via water currents or by attachment to birds or other organisms. They are also known to transmit over 50 species of trematodes, including flukes, which can be harmful to fish, waterfowl, and humans. They carry fewer parasites than the red-rim melania (Melanoides tuberculata), another Texas invasive freshwater snail (Click HERE to read more about the red-rim melania). In Texas, the quilted melania is known to carry Philophthalmus gralli, the “avian eye-fluke”, which causes blindness in waterfowl and chickens. This parasite is not native to America and its spread has been linked to both the red-rim melania and quilted Melania invading our freshwater systems. The quilted melania is also able to spread Haplorchis pumilio which is an invasive trematode known to kill native fish species, and has been shown to spread to humans in Southeast Asia when eating infected undercooked fish.

The snail has established populations in the San Antonio River in Bextar County, Landa Park in New Braunfels, Comal County, and the San Marcos River in Hays County, as well as many springs within that general vicinity. To learn more about the Quilted Melania and management options visit the TexasInvasives info page. If you believe you have found a Quilted Melania, please report it to invasives@shsu.edu.

Opportunities To Get Involved
Looking for participants for the following surveys: 

Citrus Greening Workshops

We need your help to safeguard Texas Citrus, and it can start in your backyard!

TISI is offering educational workshops focused on the Asian citrus psyllid and the pathogen Citrus Greening. The Asian citrus psyllid and the Citrus Greening pathogen is threatening citrus in multiple Texas counties, and we need your help to monitor the spread. The workshop will highlight what you need to look out for, address USDA-APHIS Citrus Quarantines, and offer diagnostic services if you suspect your backyard citrus has either the psyllid pest or Citrus Greening pathogen. This includes providing trapping materials, assisting with management strategies, and more.

Please contact invasives@shsu.edu so we can schedule a workshop (virtual or in-person) for you or your group this year!

Aquarium Watch: Looking for Prohibited Invasive Aquatic Species

Please help texasinvasives.org and natural habitats by looking for 14 prohibited invasive aquatic species being sold in your local aquarium store. With just one photo you can assist us in finding and documenting which stores are selling prohibited species. Texasinvasives.org will contact the appropriate Texas institutions to remove the species for sale.

If you would like more information please email invasives@shsu.edu, and mention you want to assist with our Aquarium Watch.

Invasive Species Are Harming Texas Habitats. Here's How You Can Help
Parks and wildlife officials are urging people to help slow the spread of invasive species in Texas and across the country. Here are a few simple ways that you can help prevent the spread of invasive species in your area. dallasobserver.com

Rep. Cuellar Requests $2M To Remove Invasive Species on Rio Grande for Binational Park
A proposal was announced for the Rio Grande International Study Center to put toward restoration efforts, invasive species removal, and reforestation on the Rio Grande, if passed. tmtonline.com

Human Foot Traffic and The Associated Spread Of Invasive Species
Human activities can be a leading vector for transportation of invasive species. In this research, foot traffic in urban parks and conservation areas were surveyed in order to calculate the invasive species spread in low, medium, and high foot traffic areas. ojd.library.queensu.ca

Saving Palm Trees Without Killing Bees
A new chemical weapon uses pheromones to target and kill South American palm weevils (Rhynchophorus palmarum). These beetles cause extensive damage or death in California palm trees (species from multiple genera). The current pesticides on the market kill more than the target beetle, including environmetally important insects, like bees. phys.org

2022 ‘Lionfish Challenge’ Underway in Florida to Remove Invasive Species
It’s that time of year again! The 2022 annual Lionfish Challenge has started in Florida and will continue through September. This tournament encourages anglers and divers to aid in the removal of invasive lionfish (Pterois volitans) from Florida waters. fwcreefrangers.com

Pets Or Threats? Goldfish Might Be Harmful to Biodiversity
Pet owners releasing unwanted pets into the wild is a major problem. Researchers focused on the ecological risks posed by goldfish (Carassius auratus) and white cloud mountain minnow (Tanichthys albonubes) on other commonly traded fish species. phys.org

American Turtle Threatens SA Biodiversity – But Our Tough-Cookie Snakes Could Rattle an Invasion
U.S. species are finding their way to South Africa and could be an invasive problem very soon. There have been several reports of red-eared sliders (Trachemys scripta) and western diamondback rattlesnakes (Crotalus atrox) in the botanical gardens and parks of South Africa. dailymaverick.co.za

Smartphone App Helps Locate Mosquitoes and Combat Malaria
A smart phone app was established to aid in the treatment of mosquitos in areas of Africa on the same day of detection. The program could be used globally to control other types of invasive species or dangerous vectors. phys.org

Introduction Pathways of Economically Costly Invasive Alien Species
Introduction pathways play a pivotal role in the success of Invasive Alien Species (IAS). Understanding these pathways is essential to help reduce the number of introductions and the impacts IAS can cause. When combining this knowledge with the monetary impacts, one can better calculate the cost associated with stowaway, contaminant, escape, or release pathways. link.springer.com

Study Provides Long-Term Look at Ways to Control Wildfire In Sagebrush Steppe Ecosystem
The number, size and intensity of wildfires in the sagebrush ecosystem have significantly increased primarily due to climate change and the spread of invasive grasses. Researchers studied several methods for decreasing fire intensity. phys.org

If you would like to highlight a successful invasive species project or nominate a special person to be highlighted in an upcoming iWire, please send the details to iwire@texasinvasives.org.
 

Citizen Scientists Spotlight
Volunteers remove invasive privet in San Antonio

A group of volunteers has been working diligently to rid San Antonio’s only nature sanctuary of all its invasive species. The 53-acre sanctuary, called Headwaters Sanctuary, is located behind the University of the Incarnate Word's baseball fields. It is owned by a nonprofit organization run by the Sisters of Charity of the Incarnate Word. The sanctuary only has one full-time staff member, so the many committed volunteers are a great help for the invasive species removal effort. The volunteers come to the sanctuary twice a week to continue restoration work.

Ligustrum trees, also known as privet, have been growing unchecked throughout the sanctuary. Some of the trees were purposely planted in the 19th century during a beautification project, however, most of the invasive trees in the sanctuary have grown due to spread from nearby residences that planted privet in their landscape. There are many different species of privet that are invasive in Texas, including Chinese privet (L. sinense), European privet (L. vulgare), glossy privet (Ligustrum lucidum), Japanese privet (L. japonicum), and Quihoui privet (L. quihoui). All of these invaders can quickly out-compete native species and choke out vegetation by creating dense thickets, starving native plants of sunlight, soil, and water. Ligustrum trees can also be harmful to the local Texas bird population.

The invasive trees in the sanctuary are chopped down and the stumps are sprayed with herbicide to prevent regrowth. Regrowth of native species can be seen along the forest floor in areas that have already been cleared of invasives. This invasive species removal project is expected to be completed by 2024. The goal is to remove the invasive trees so native species can grow, and wildlife can return to the area.

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.

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