October 2021
Biocontrol for Air Potato

The air potato (Dioscorea bulbifea) is an herbaceous vine with the ability to reach lengths of 65 feet (20 m) or more. The vine, with its sprawling stems and heart-shaped leaves, will climb and twist as it grows, smothering and out competing native vegetation. The air potato leaf beetle (Lilioceris cheni) has recently been found to combat the invasive vine, and is being used for a biological control of the air potato in the U.S., especially in Florida.

Lilioceris cheni adults are about 9 mm long and 4 mm wide. Their head, thorax, abdomen, and legs are black, while the coloration on the elytra ranges from brown to bright red. There are four larval instars. The larvae’s legs, head, and prothoracic shield are black, however the abdominal color varies based on the stage: Younger instars are yellowish to reddish, and the later instars are grayish to red.

Female adult beetles deposit eggs in clusters on the underside of young air potato leaves. The process of oviposition deforms the leaves, causing them to curl at the edges and become cup-like around the eggs. The larvae and adults feed on young and old leaves, skeletonizing them from the underside. The larvae are even known to feed on the arial bulbils, the potato-like tubers that drops from the stems to produce the next generation of plant. The feeding habits of the leaf beetles negatively affect plant growth and reproduction, inhibit vine elongation, and reduce the ability of the vine to climb vertical structures. Extensive host range testing by the USDA/ARS Invasive Plant Research Laboratory in Fort Lauderdale demonstrated that the air potato leaf beetle is a specialist feeder on air potato and is self-sustaining if the host plant is present (beetles cannot complete development on other plants). The air potato leaf beetle is only known to feed on air potatoes in its native range of Asia and Africa. Based on these collective findings, the USDA’s Animal Plant Health Inspection Service (APHIS) issued a permit for release in the U.S. The beetles were first released in Florida as a biological control in 2012. Last year (2020), they were released in areas of The Woodlands, TX. Recent reports from The Woodlands Township announced that the beetles survived the freeze and are munching away on the air potato plants around the release sites (see image to right).

Although the air potato leaf beetle is effective at weaken the vine, reducing growth and slowing bulbil production, it will not completely eliminate the plant. It is necessary to remove and dispose of the remaining vine and bulbils to reduce the chance of spread. For more information about the air potato, see texasinvasive.org.

If you believe you have identified an air potato vine, please email invasives@shsu.edu and include the following: an image, an approximate number of vines present, the location (including whether it is on public or private land), and whether bulbils are present.


air potato lead beetle. the woodlands townshipair potato lead beetle larvae. the woodlands township 3
Air potato leaf beetle (Lilioceris cheni), Top: Adult beetle. Bottom: Larvae and leaf damage. Credit: The Woodlands Township.

air potato leaf beetle damage. the woodlands township
 Leaf and vine damage on air potato plants (Dioscorea bulbifea) after air potato leaf beetle release in The woodlands, Tx, area. Credit: The Woodlands Township.

Hippos as Humans

In Colombia, Pablo Escobar’s hippos have been a matter of conflict and debate for years. The cocaine kingpin brought four hippos (Hippopotamus amphibius) to his zoo, but since his death in 1993 their numbers have grown to an estimated 80-100, and have made their way into the country’s rivers. One side of the debate views the hippos as an invasive species, reporting they compete with the local wildlife for food and pollute the local water ways. The other side believes the hippos could actually be helping the ecosystem by replacing species that have long since been extinct, like giant llamas (Hemiauchenia paradoxa). Read more about the hippos “rewilding” their environment here and here.

As part of the battle to save the hippos from being culled, they have become the first non-human creature to be legally considered people or “interested persons” with legal rights by the U.S. courts. In Colombia, non-human animals have the right to bring lawsuits that protect their interest as long as they are not ‘compelled’ to do so. An interested party is then allowed to go to the U.S. federal court to obtain documents or testimony. This is what happened in the case of the Pablo Escobar hippos. The Animal Defense League Fund (ADLF), an animal law advocacy group, applied to the U.S. federal court on behalf of the hippos. Two wildlife experts from Ohio shared their expertise about non-surgical sterilization as an alternative to culling the rapidly growing population. The application was granted, meaning the District Court recognized the hippos as people, the first time non-human creatures have been recognized in U.S. history. The court order authorizes the hippos to exercise their legal right to “obtain information” in the U.S., or have a representative do so in their stead. Some believe this a small step in the legal case for the Pablo Escobar hippos and for animal rights in general. However, legally this ruling has no impact in Colombia because it will be the Columbian authorities that decide how to deal with the hippos, not American authorities. A government agency in Colombia has already started sterilizing some of the hippos, but the safest method to proceed is up for debate.

 
Hippos in the lake on the former private estate of drug kingpin Pablo Escobar. Fernando Vergara.APPablo Escobar’s hippos in the lake on the former private estate in Colombia. Credit: Fernando Vergara, AP

Non-Native Mangroves create Novel Habitats

In most situations, invasive or non-native species can damage the environment in which they are introduced. However, there is growing recognition that in some instances, non-natives species may provide ecosystem services in areas where climate and land use are rapidly changing, subsequently replacing or providing ecosystem services that were previously lost. A recent study of non-native red mangrove (Rhizophora mangle) habitats on Hawaii’s Moloka’i Island has examined how they provide beneficial services to the ecosystem.

On this island, the mangroves were introduced in 1902 to stabilize eroding coastal mudflats and reduce the degradation of adjacent coral reefs. Since then, the mangroves have spread across the intertidal zone of Moloka’i and neighboring islands creating novel habitats. The mangroves are argued to be both beneficial and detrimental to the environment, but at what point does the one outweigh the other. Mangroves provide a positive influence on sediment retention and water quality, but they may threaten ancient Hawaiian fishponds, the local aquaculture. Some birds benefit from the mangroves, using them as shelter, while some waterbirds are limited by the mangroves as they reduce the mudflats that the birds rely on for foraging and nesting.

Researchers decided to compare mangrove habitats to open-coast and fishpond habitats without mangroves. The study found that the zooplankton communities in mangrove stands were comparable to those of the open coast. Zooplankton are a key component of marine ecosystems. Researchers also found that while some species of zooplankton were less abundant, others rare species were only present in mangrove habitat, suggesting that these habitats may benefit, rather than impede, zooplankton. The research paper suggests that in the face of declining fisheries, threatened reef ecosystems, and changing climatic and ocean conditions, some invasive species, such as mangroves, provide a valuable economic service that may outweigh their negative effects.

To read more about the mangroves and decision-making process involved in managing these invasive species: Lewis and Granek, 2021


A mangrove forest in the nation of Palau. (USDA Forest Service photo)
A mangrove forest in the nation of Palau. Credit: USDA Forest Service photo
 
 The island of Moloka'i and its location in the Hawaiian Islands 
The island of Moloka'i and its location in the Hawaiian Islands. Examples of (b) a paired site within a fishpond and (c) a paired open-coast site outside a fishpond. M open-coast mangrove, O open-coast non-mangrove, PM fishpond mangrove, PO fishpond non-mangrove. Credit: Lewis and Granek, 2021.
 

Hybridization in Invasive Brown Anoles

Hybridization often occurs in invasive species and is often an important driving force behind their success. In a paper by Bock et al. (2021), researchers examine how a rare kind of hybridization, called interspecific hybridization, is seen in invasive populations of brown anoles (Anolis sagrei), but is rare in native populations. In the native range of Cuba, brown anoles do not interbreed with other populations, and the populations are highly genetically structured. However, when Cuban anoles are introduced to the U.S., these rules seem to change. Invasive populations show evidence of hybridization with native-range lineages; their genetic structure has stabilized, indicating that large-scale contemporary gene flow is limited among invasive populations.

The researchers also concluded that hybrid persistence in invasive populations is affected differently by natural selection. They identified a large-effect X-chromosome locus that is associated with limb length. In their native range, this trait is important during local adaptation of populations, affecting how fast the lizards can run and how far they can jump. However, in invasive population, little selection at this locus was detected. The combined findings supports that a change in natural selection, environmental change, and evolutionary change can increase and support hybridization in invasive populations.


brown anole (Anolis sagrei) Mike Pingleton. University of Illinois at Urbana-Champaign
Brown anole (Anolis sagrei). Credit: Mike Pingleton, University of Illinois at Urbana-Champaign.

 
 
 
 

Are You Eating My Crops? 6 of 12

The black maize beetle (Heteronychus arator) is a pest to pasturelands, turf, and agricultural crops in Australia, New Zealand, and Africa, and is the sixth headliner in our 12-month series called ‘Are you eating my crops?’ Individual pests chosen for this series have not yet been reported in Texas, but are on the ‘Watch List’ due to their high level of pest importance or risk due to host availability. During this series we will cover several different crop pests, what to look for, what they look like, and where you can find more information about them. If you ever have question or concerns regarding the headliners of this section, feel free to email invasives@shsu.edu.

Adult black maize beetles are between 12-15 mm long, with a shiny black topside and a reddish-brown underside. The adult is the main pest stage, is the only aboveground stage, and is capable of flight. The entire rest of the lifecycle is spent below ground. Eggs are white, oval, and about 1.8 mm long at the time oviposition. As they develop, they will become larger and rounder. Females lay eggs individually at a soil depth of 1-5 cm. Females will lay between 12 to 20 eggs. Eggs hatch after about 20 days. There are three larval instar stages, measuring 1.5 mm, 2.4 mm, and 4.0 mm respectively. The third instar can grow to 25 mm (about 1 inch) when fully developed. The grub-like larvae are creamy white with a brown head and hind segments. They have three pairs of legs and resemble white “curl grubs”. Larvae eat plant roots and underground crops, potentially causing damage to turf, horticulture crops (like potatoes), and ornamentals. The preferred host of the larvae seems to be turf grasses.

Black maize beetles cause significant damage to corn, grapes, potatoes, small grains, sugarcane, and turf grasses. In corn, the beetles will chew into the stems of the growing plant just below the soil surface, causing rapid wilt of the growing center leaves and death of the plant. The damaged area of the plant has a frayed or shredded appearance caused by the beetles consuming the soft tissue, but leaving the fibrous material behind. This damage can distinguish it from the damage caused by cutworms. In grapes, the beetle will chew the cortex of the stem just below the soils surface, causing ‘ringbarking’ of the vine, wilting, and vine collapse. Ringbarking will cause growth distortion and is potentially fatal to the plant.

Black maize beetles can be mistaken for many other dark colored beetles, especially other scarab beetles. If you believe you have identified a Heteronychus arator infestation or have collected a specimen, please send a picture to invasives@shsu.edu.

To read more about the black maize beetle, see the USDA fact sheet 1 or USDA fact sheet 2.



Illustration of each stage of the life cycle of the black maize beetle. NSW Agriculture-1
Illustration of each stage of the life cycle of the black maize beetle (Heteronychus arator). NSW Agriculture
 
black maize beetle (Heteronychus arator). pest and diseases image library
Black maize beetle. Pest and Diseases Image Library.

Black beetle larvae damage to tall fescue. photos- oregonstate.edu AgResearch
Black beetle larvae damage to tall fescue. Credit: oregonstate.edu, AgResearch

Interior’s Office of Policy Analysis Seminar

November 8, 2021; 12:15-1:45 pm ET - Wildland Fire and Invasive Species

Webcast Only: Microsoft Teams Live Event (You can also use this link to access the recorded seminar after the event.)

The magnitude of recent fire seasons has heightened awareness of the Nation’s wildfire crisis. In many areas throughout the U.S., the spread of invasive plants has contributed to an increase in the size, frequency, and severity of wildfires. This panel will highlight the intertwined dynamics of wildland fire and invasive species, with experts addressing the underlying science and ecology, as well as agency perspectives and management strategies from the invasive species and wildland fire communities. This will also include looking at the different stages of the wildfire and invasive species management cycles: proactive pre-fire planning and fuels treatment, wildfire response, and post-fire stabilization and restoration. The panel will conclude with a discussion on integrating efforts at different scales as well as on potential opportunities for future collaboration across the invasive species and wildland fire management communities. For additional information about this event, please contact Malka Pattison at: malka_pattison@ios.doi.gov






boardmeeting
Credit: Kylee N Kleiner, TRIES.
 

Pre-Border Prevention: A New Conversation on Invasive Pest Pathways Through Trade

Webinar Series: December 7-10, 2021

Original event intended for November 2020 postponed due to COVID-19. This digital series of webinars will focus on the successes and implementation gaps associated with ISPM15, the inspection protocol for wood pallets and other packaging. It is actively under development now. Details will be posted as soon as they are available, entomologychallenges.org


border control. pesttrader.comCredit: pesttrader.com

North American Invasive Species Management Association Training Webinars

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:

  • November 17, 1pm- USGS and USFWS collaborative project to conduct a national horizon scan for organisms in trade. REGISTER.
  • December 15, 1pm- Classical Biological Control of Weeds- About misconceptions and untapped opportunities. REGISTER.
  • January 19, 1pm- History and effectiveness of injurious wildlife listing under the “Lacey Act”. REGISTER.





NAISMA logo

African Fig Fly Reported in Texas

In mid-October, a horticulture agent received fly samples from a Fredericksburg farmer who thought he had a spotted wing dropsila infestation in his muscadine grapes. Upon inspection, flies with distinct silver and black longitudinal stripes along the thorax were found amongst the samples. These samples were unusual as no native species of Drosophilae have markings like this. Under suspicion of being African fig flies (Zaprionus indianus), the specimens were sent to a Sam Houston State University Entomologist and confirmed to be the non-native flies. The specimens are now in the Sam Houston State Natural History Collection. African fig flies have been reported in Texas once before, in the Dallas area, in 2019.

The African fig fly is known to attack figs, grapes, berries, and other smooth-skinned fruit. The flies prefer fallen fruit to lay their eggs, but they have been known to attack fruit on the vine especially if it's damaged by other insect activity. Because they are generalist, these flies could become a problem in various parts of Texas. For more information about the African fig fly visit the TISI information page or read more about its distribution in Pfeiffer et al., 2019.



Fig-Fruit-Fly. Mike Ferro. bugguide
African fig fly (Zaprionus indianus). Credit: Mike Ferro, bugguide.net Copyright: CC BY-ND-NC 1.0
 

Invasive Spotlight:

Cactus Moth
(Cactoblastis cactorum)

The invasive cactus moth (Cactoblastis cactorum) is a considerable threat to the native Opuntia cactus population and the ecosystem it supports. The larvae of the cactus moth live and feed communally inside the pads of any species of prickly pear cacti, which eventually kills the plant if the infestation is extreme enough. The cactus moth, a native of South America, is so efficient at eliminating Opuntia cacti that it is used as a biological control agent in areas where Opuntia are invasive. The cactus moth has the potential to destroy Opuntia communities from Texas down through Mexico.

Cactus moth larvae are pink-cream colored at first but as they age they become bright orange-red with large dark spots, which will eventually join to form transverse bands. Mature larvae are 25 to 30 mm (about 1 inch) long. The larvae are much easier to identify than the non-descript adults. Nothing else looks like the larvae. The adults are gray-brown moths with faint dark spots and wavy transverse lines marking the wings. The rear margins of the hindwings are whitish, and semitransparent; and the antennae and legs are long. The wing span of the adults ranges from 22 to 35 mm. Females lay on average 70-90 eggs in a distinctive stick-like formation that extends out from the cactus pad.

Damage to the cactus pads is caused by feeding and can be identified by characteristic oozing of internal plant juices where the larvae entered the plant, and insect droppings. The larvae are gregarious and will remain on the inside of the cactus pads as they mature, continuing to eat the pad from the inside, often resulting in a translucent pad. Mature larvae will emerge from the cactus pad to form cocoons and pupate on the ground at the base of the cactus. Adults will emerge and disperse, repeating the reproductive process. Adults only live for an average of 9 days but can spread far distances in a short time.

Unfortunately, the cactus moth has now been found in Texas, in Brazoria County in 2018 and in Calhoun, Colorado, and Matagorda Counties in 2019. It is established in Florida and South Carolina and has been reported in Alabama, Mississippi, and Louisiana. If you believe you have found cactus moth damage, egg sacks or larvae, please take a picture and REPORT IT! on TexasInvasive.org.

cactus moth. susan ellis. USDA APHIS PPQ
cactus moth larvae. Ignacio Baez. USDA Agricultural Research Servicecactus moth egg stick. D. Habeck and F. Bennett University of Florida
Cactus moth (Cactoblastis cactorum) adult, larvae, and egg stick. Credit: Top) Susan Ellis, USDA APHIS PPQ. Middle) Ignacio Baez, USDA Agricultural Research Service. Bottom) D. Habeck and F. Bennett, University of Florida.

fras oozing from cactus. arc.agric.zacactus moth damage. Rebekah D. Wallace. university of georgia
Top: Insect fras oozing from cactus. Credit: arc.agric.za. Bottom: Damage due to larval feeding. Credit: Rebekah D. Wallace, University of Georgia.
 

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.

Air Potato Survey

Help Texas Research Institute for Environmental Studies conduct an air potato survey by actively reporting any infestations seen in your area. The air potato (Dioscorea bulbifera) is a fast growing, high climbing vine. Potato-like tubers are the primary means of reproduction for this vine. They can be as small as a marble or as large as a softball. Native yams are often confused for air potatoes, to avoid this confusion please refer to the key below:

- Plants rhizomatous; bulbils never produced in leaf axils; petiole base never clasping the stem; Native D. villosa
- Plants tuberous; bulbils produced in leaf axils; petiole base sometimes clasping the stem; Invasive D. bulbifera

For additional information, please refer to the TexasInvasives information page.

If you believe you have identified an air potato vine, please email invasives@shsu.edu and include the following information: an image, an approximate number of vines present, the location (including whether it is on public or private land), if bulbils are present (the potato-like tubers that emerge from the stem).

 

 


Citrus greening. JM Bove

Leaf mottle on grapefruit, a characteristic symptom caused by citrus greening bacterium but also seen on trees infected by Spiroplasma citri. Credit: J.M. Bove.















Armorded catfish. Photographer United States Geological Survey
Armored catfish (Hypostomus plecostomus). Credit: United States Geological Survey.













air-potato (Dioscorea bulbifera)2 bulbil. credit Karen Brown
Air-potato (Dioscorea bulbifera), bulbil emerging from leaf axil. Credit: Karen Brown.

More News

Team Discovers Invasive-Native Crayfish Hybrids in Missouri
In a study of crayfish in the Current River in southeastern Missouri, researchers discovered that the virile crayfish (Faxonius virilis) was interbreeding with a native crayfish, potentially altering the native's genetics, life history and ecology. sciencedaily.com

Meet the Italian Wall Lizard, NJ’s Other Invasive Species
The Italian wall lizard (Podarcis siculus) has been spotted around the Northeast for over 30 years, however their origin was a mystery until 2010. An anonymous NJ resident revealed how the invasion got started. nj1015.com

How Socioeconomic Factors Can Influence the Spread of Invasive Plants
Predicting the spread of nonnative plants that have the potential to become invasive may seem like an unachievable goal. But a recent study found a connection between the movement of invasive species and socioeconomic factors. phys.org

Invasive Potential of Tropical Fruit Flies in Temperate Regions Under Climate Change
Tropical fruit flies are considered among the most economically important invasive species detected in temperate areas. Weather-driven physiologically-based demographic models are used to estimate the geographic range, relative abundance, and threat posed by four tropical tephritid fruit flies. nature.com

Spotted Lanternfly, a Crop-Killing Pest, is Hitchhiking and Hopping Its Way to the Midwest
The spotted lanternfly (Lycorma delicatula) is getting a lot of media attention as it continues to move from state to state since its accidental introduction in 2014. Officials fear it could be heading to Michigan next. phys.org

Anglers need tailored messaging to inspire action on invasive species
Lakeside education campaigns discourage anglers from transporting aquatic hitchhikers between lakes, but new research examines how those campaigns are less effective than they could be. According to the study, the key could be tailoring messaging in accordance with anglers' value systems and risk perceptions. sciencedaily.com

Don't Underestimate Rabbits: These Powerful Pests Threaten More Native Wildlife Than Cats or Foxes
In Australia, rabbits have been taking a toll on the native wildlife since their introduction in 1859. Recent research examines the conservation benefits of biocontrols that were used to manage the rabbit problem. The article also examine how rabbits are often underestimated in conservation when compared to other predators. phys.org

Crayfish And Carp Among the Invasive Species Pushing Lakes Towards Ecosystem Collapse
A recent study has found certain invasive, non-native species can disrupt lakes to the point of rapid ecosystem collapse, contaminating water for drinking, aquaculture, and recreation. sciencedaily.com

The Impact of Coastal Hardening on Local Ecosystems
Coastal hardening happens when humans build structures on or near the edge of the ocean. When natural soft coastline is replaced with hard materials the geography becomes simpler and is often favored by invasive species. phys.org

Hidden Costs of Global Illegal Wildlife Trade
Researchers have highlighted that the illegal and unsustainable global wildlife trade has bigger ramifications on our everyday lives than you might think. sciencedaily.com


 
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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.
 


 
Sentinel Pest Network and Invaders of Texas Workshops

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.

Upcoming Workshops:

-None-

For more information or to register to attend a free workshop, please visit the Workshop Page.