Are We Being Invaded by Cuban Treefrogs?  Maybe…

Are We Being Invaded by Cuban Treefrogs? Maybe…

We have written about this guy before.  The Cuban Treefrog is a potential threat to the Florida panhandle.  According to EDDMapS, there are 13 records between Pensacola and Madison County.  The records I am aware of are single individuals who appeared after the homeowner purchased landscaping plants (or flowers) from a local “box store”.  In the last couple of weeks, I have again heard of two cases where individuals were found either at the “box store” garden center – or on their property after purchasing plants from such.

Image by Dr. Steve A Johnson 2005.

We all know that one individual does not a problem make.  However, if multiple people continue to find them and they escape.  Then eventually the numbers could get high enough where breeding populations could form.  It is known that CTFs prefer to hang around humans and are not common in natural areas.  So, this COULD make it easier for them to find each other over time and populations begin to establish themselves.  We do not want this.

 

Why? What problem can a small frog cause?

 

Well, first – they are (as many invasive species are) aggressive consumers – feeding on local treefrogs to where their populations begin to decline.  With that “space” left open, the invasive species quickly fills in and increases their populations.  Over time you have a “monoculture” of CTFs and lower biological diversity within the local frog populations.

 

Is this a problem?  Does it matter which frog is occupying the space?

It can.  Lower biodiversity can make it difficult for frog populations to recover from environmental stress, such as changes in habitat, damage due to storms, changes in prey species.  Lower biodiversity can make populations more susceptible to the spread of disease and the potential elimination of the species because no one in the population is genetically different enough so that there are those with resistant genes.  Then there is the case as to whether the native frog predators will eat the invasive CTFs.  They do have a strong enough toxin in their skin to cause allergic reactions in humans.  This could be enough to keep the predators from eating.  This will cause the CTFs populations to increase even more (classic invasive story – fewer predators) and the decline of native frog predators – some of which can directly, or indirectly, can have an economic impact on our community.  So, yes – it can matter.

 

Second, CTFs are known to “hang out” in electrical panels.  As many as 30 were found in one electric panel at the zoo in New Orleans.  Inhabiting such places have been known to cause electrical problems, including short circuiting HVAC systems.  We do not want this.

This Cuban Treefrog was found at the site of the building of a new home in the Pensacola area.
Photo: Keith Wilkins

Third, their calls have been described as “loud and sounding like a squeaky screen door”.  This apparently drives some folks crazy.  The noise is just too much.  Of course, you would need a lot of CTFs to create such an unwanted serenade, but (reading above) you can see this could happen.

 

So, we would like to stop this before they become established, like the brown anoles and the lionfish.

What can we do?

 

First, be aware of what you are bringing home when you purchase landscaping plants from local vendors.  Find out where their plants are grown and, if from the central/south Florida area, inspect the plant BEFORE you bring it home to make sure you are not bringing home anything else.

 

Second, if you find one – please consider reporting it.  You can do this at www.EDDMapS.org.  Log in (you will need a password – it is free) and report new sighting.  If you get confused on how contact your local extension office and they can help walk you through it.

Get a photo if possible.  We want to verify that it is a CTF and not one of the local native ones.

Cuban Treefrog
Photo: UF IFAS

How do you tell them apart?

First, it must be a treefrog.  Treefrogs will have webbed feet but there are large toepads at the end of each toe so that it can cling to trees, and the side of your house.

Second, CTFs are much larger.  Our native treefrogs will reach about 2”, CTFs can reach 5”.

Third, what if it is a small CTF?  If you turn them over, you will see their skeleton through the skin – and it will appear blue – the native species are not blue.

Fourth, they have “warty” skin.  Many of the natives will have smooth skin.  The local cricket frogs will have warty skin, but they are smaller and have a triangle shaped dark spot on top of the head between the eyes – the Cuban Treefrog does not have this.

Fifth, they do not have stripes.  They may be solid in color or have patches of darker areas.  They can change color and have been seen as green, gray, brown, and even a light beige/white color.

Sixth, the skin between their eyes is fused to their skulls – not so in the native frogs.

 

Note: the CTF does produce a strong toxin through the skin.  Though not deadly, it can be irritating to the skin and more so to the face.  If you handle without gloves, you should not touch your face until you have washed well.

 

Third, educate your neighbors to let them know.  Not just about the CTF but other potential invasive threats that could be hitchhiking up this way.  With a community effort we should be able to keep them from establishing here.

Fear the Mussel?

Fear the Mussel?

Well, maybe not…

But there could be reason to keep an eye out.  We are not talking about the common ribbed or hooked mussels we found in the Pensacola Bay area.  We are talking about an invasive species called the green mussel (Perna viridis).

The green mussel differs from the local species by having a smooth shell and the green margin.
Photo: Maia McGuire Florida Sea Grant

Why be concerned?

 

By nature, invasive species can be environmentally and/or economically problematic.  In this case, it is more economic – which is unusual, most are more environmental concerns.  The big problem is as a fouling organism.  Like zebra mussels (Dreissena polymorpha), green mussels grow in dense clusters, covering intact screens to power plants, intact pipes to water plants, and can displace native spaces by competing for space.  It has been determined they can grow to densities of 9600 mussels / m2 (that’s about 10 ft2) and they can do this on local oyster reefs – displacing native, and economically important, oysters.  They grow quickly, being sexually mature in just a few months, and disperse their larva via the currents.  To make things more interesting, they may be host to diseases that could impact oyster health.

 

So, what is the situation?

 

They are from the Indo-Pacific region, found all across southeast Asia and into the Persian Gulf.  In this part of the world they are an aquaculture product.  There was interest in starting green mussel aquaculture in China, and in Trinidad-Tobago.  After they arrived in Trinidad, they were discovered in Venezuela, Jamaica, and Cuba – it is not believed this was due to re-locating aquaculture, but rather by larva dispersal across the sea… they got away.

This cluster of green mussels occupies space that could be occupied by bivavles like osyters.

It would be an easy jump from Cuba to Florida – and they came.  The first record was in 1999 in Tampa Bay.  They were found while divers were cleaning an underwater intake screen.  Dispersal could have happened via larva transport in the currents, but it could have also occurred via ship ballast discharge at the port – this is how folks think it got there, they really do not know.  From there they began to spread across the peninsula part of the state.  They have been reported in 19 counties, most on the Gulf coast, and there is a record from Escambia County – however, that one was not confirmed.

 

How would I know one if I saw it?

 

They prefer shallow water and are often found in the intertidal zones – attached to pilings, seawalls, rocks.  As mentioned, they grow in dense clusters and should be easy to find.  They are long and smooth, with a mean length of 3.5 inches.  There was one found in Florida measuring 6.8 inches, which they believe is a world record.  Mussels differ from oysters in that they attach using “hairy” fibrous byssal threads – in lieu of cementing themselves as oysters do.  As mentioned, the shell is smooth and may have growth rings, but it lacks the “ribbed” pattern we see on the local ribbed and hooked mussel.  It will have a green coloration along the margin – hence its name, and the interior of the shell will be pearly white.

The shell at the far right is the common ribbed mussel native to our local salt marshes. Just to the left is the invasive green mussel. Can you tell them apart?
Photo: Maia McGuire Florida Sea Grant

They prefer salinities between 20-28‰, which would be the lower portions of the Pensacola Bay system (Santa Rosa Sound, Big Lagoon, maybe portions of Pensacola Bay).  They are not a fan of cold water.  They do not like to be in water at (or colder) than 60°F.  Some biologist believe it is too cold in the panhandle for these bivalves, but we should report any we think may be them – to be sure.

 

What do we do if found?

1)      Get a location and photos.  Pull some off and get up close photos of an individual.

2)      Report it.  You can do this by contact the Escambia County extension office (850-475-5230 ext.111), or email me at roc1@ufl.edu.

3)      If there is a method of removing all of them, do so.  But this should be done only after the identification is verified.  When removing try to collect all the shell material.  The fertilized gametes within, if left, can still disperse the animal.

4)      They are suggesting boat owners check their vessels when trailering.  Avoid transporting them from one body of water to another.

5)      I would recommend that marina owners do the same – check boats and pilings.

It appears the mean temperature of the Gulf is increasing.  With this change it is possible some of the tropical species common in south Florida could disperse to our region, and that could include the green mussel.  The most effective (and cheapest) way to manage an invasive species is catch them early and remove them before they can become established.

 

For more information on green mussels in Florida read https://edis.ifas.ufl.edu/pdffiles/SG/SG09400.pdf.

Getting Rid of Chinese Tallow Trees

Getting Rid of Chinese Tallow Trees

Chinese Tallow Tree in Early Spring

Chinese Tallow, also known as the Popcorn Tree, was introduced in the US over 200 years ago.  Ben Franklin sent seeds over in 1772.  Although Franklin was blamed for the invasion in the U.S. Gulf Coast, scientists performed genetic testing and have concluded that the blame actually lies with federal biologists who imported some Chinese tallow trees around 1905.  Popcorn trees have continued to spread throughout the US since then.

For many years, people have planted them in their landscape for shade and fall color.  Once established, they invade natural areas, pastures, wetlands and yards.  They out-compete native and non-invasive trees and shrubs.  In 1998, Chinese Tallow was added to the Florida Department of Agriculture and Consumer Services Noxious Weed list.  Plants on the Florida Noxious Weed list may not be introduced, possessed, moved, or released without a permit.

 

Landowners and homeowners can help with this problem tree by removing and replacing them with a native or non-invasive tree like black gum, maple, dogwood, or crepe myrtle.  Mature trees can be cut down with a saw and the stump promptly treated with an herbicide with the active ingredient, triclopyr amine.  You should try to make the final cut as low to the ground as possible.  You can use a paint brush to apply the herbicide to the stump.  A basal bark application of triclopyr ester plus a basal oil carrier can be used on smaller trees.  Treat the trunk to a height of 12 to 15 inches from the ground, thoroughly wetting it with the herbicide mixture.  Basal bark treatments are only effective on saplings and seedlings less than 6 inches in stem diameter.  Sometimes suckers may sprout from remaining roots.  A foliar application can be used on these sprouts from July to October, before onset of fall color.

 

For more information about Chinese Tallow trees or other invasive weeds, go to:  https://edis.ifas.ufl.edu/ag148.

National Invasive Species Awareness Week 2020 – An Opportunity for Action

National Invasive Species Awareness Week 2020 – An Opportunity for Action

February is a month filled with special celebrations and events like Valentine’s Day, President’s Day, Groundhog Day, and of course NISAW!

 

NISAW or National Invasive Species Awareness Week isn’t as famous or beloved as the other February dates. You likely won’t get a day off, have a special date or receive a present from your loved ones. However, NISAW is an important time to remember and learn about invasive species that impact our beloved natural areas.

 

Invasive species originate from other continents and have adverse impacts on our native habitats and species. Many of these problem non-natives have nothing to keep them in check since there’s nothing that eats or preys on them in their “new world”.

 

This year NISAW is being celebrated February 24 – 28. It is the largest invasive species awareness effort in the U.S. You can learn more at https://www.nisaw.org/nisaw-2020/

or on Facebook at @invasivespeciesweek. Search other social media outlets using #NISAW or #invasivespecies.

 

We would like you to help celebrate NISAW in a more meaningful way, beyond awareness and clicking a few links or sharing social media posts with your friends. Bay County and Northwest Florida need your help in fighting invasive species this year, especially the air potato vine.

 

Air potato vine originated in Asia and Africa. It was brought to Florida in the early 1900s. People moved this plant with them, having used it in the past for food and medicine. Today, we know raw forms of air potato are toxic and consumption is not recommended. This quick growing vine reproduces from tubers or “potatoes”. The potato drops from the vine and grows into the soil to start new vines. Air potato is especially a problem in disturbed areas like utility easements, which can provide easy entry into forests. Significant damage can occur in areas with heavy air potato infestation because vines can entirely cover large trees. Some sources report vine growth rates up to eight inches per day!

Air potato vines covering shrubs and trees in Bay County Florida.
Photo: Scott Jackson

We plan to start local NISAW activities a few days early on February 22nd, with the collection of air potato vine tubers or potatoes also known as bulbils of this species. Bay County Conservancy will host an “Air Potato Round-Up” behind Panama City Orthopedics in the Audubon Nature Preserve which is located at State Ave and 19th Street. The collection and workday is scheduled from 9am until Noon. Volunteers are encouraged to wear long pants, gloves, comfortable shoes or waterproof boots. Expect a rewarding but dirty job! For details and specific information please contact Teresa Nooney at 850-814-4755.

 

Other communities are promoting other NISAW workdays and events known collectively as “Weed Wrangle”. UF/IFAS Extension Bay County and Escambia County will serve as collection sites for Air Potato vine bulbils through the last week of February as permitted and designated by the Florida Department of Agriculture and Consumer Services (FDACS). For additional details contact and coordinate delivery with your county UF/IFAS Extension Office.

Ron Houser weighs collected air potato bulbils.
Photo: Teresa Nooney

Because air potato vine is a regulated invasive species, only UF/IFAS Extension offices working directly with FDACS under their permit will be able to accept air potatoes. Air potatoes must be delivered in person, you cannot mail or ship them. Participating offices are:

UF/IFAS Extension Bay County, https://sfyl.ifas.ufl.edu/bay , 850-248-8091.

UF/IFAS Extension Escambia County, http://sfyl.ifas.ufl.edu/escambia , 850-475-5230.

Unfortunately, mechanical removal of vines and herbicide applications is difficult and may cause harm to desirable plants making it very difficult to manage. Removing and collecting air potato vine tubers helps in the control of this plant. When the potatoes are left in place, they will produce new vines the following spring.

 

The bubils that are collected by local UF/IFAS Extension offices will be given to Florida Department of Consumer Services (FDACS) air potato beetle rearing labs. This will help them raise more beetles that can be distributed throughout the state for establishment and vine control.

Air potato beetle crawling on a leaf stem.
Photo: Julie McConnell

The air potato leaf beetle was released in Florida in 2011. This beetle was originally identified as a natural predator of air potato vine within its native range and was found to be effective in keeping growth in check as well as being safe to other plants because it has such a specific dietary source. Air potato leaf beetles eat only air potato vines! Only after years of extensive research to ensure the safety of Florida ecosystems, was the air potato leaf beetle cleared as for use as a biological control insect to aid in the control of air potato vine.  Air potato beetle releases are monitored and evaluated by United States Department of Agriculture (USDA) researchers and scientists as they continue to establish populations and monitor the work of air potato vine leaf beetles throughout the state.

 

An Equal Opportunity Institution. UF/IFAS Extension, University of Florida, Institute of Food and Agricultural Sciences, Nick T. Place, Dean for UF/IFAS Extension. Single copies of UF/IFAS Extension publications (excluding 4-H and youth publications) are available free to Florida residents from county UF/IFAS Extension offices.

Torpedograss a Challenge to Manage on Land or Water

Torpedograss a Challenge to Manage on Land or Water

Tordpedograss (Panicum reopens) is one of the most concerning weeds in Florida and now easily found in the Panhandle. This weed’s favorite habitat is in or near ponds and ditches, but will spread across lawns and pastures.

A native grass of both Africa and Asia, torpedograss was introduced through seed in the U.S in the late 1800’s as a forage crop for livestock. Torpedograss is in the family Poaceae, along with other grasses such as the persistent invasive threat, cogongrass, as well as common bermudagrass. It gets its name from the sharply pointed tip and not only is it exceptionally fast spreading, it can grow as tall as 3 feet. Torpedograss is a poor seed germinating species in our climate and primarily relies on rhizome expansion.

Photo: Tordpedograss (Panicum reopens).

Credit: Ray Bodrey, UF/IFAS Extension Gulf County.

This plant has a tendency to choke out and completely take over native vegetation. Agronomist in south Florida have been concerned about it for years. In 1950, the University of Florida agricultural experimental station warned: “Torpedograss is a serious weed when established in farm or grove land and indiscriminate planting without the regard to future crops or adjoining land is dangerous.” (Hodges and Jones).

Photo: Tordpedograss pond infestation.

Credit: Jeff Hutchinson, UF.

So, what is the impact of torpedograss on Florida?

Since 1992, torpedograss has taken over 70% of Florida’s public waterways. Lake Okeechobee is considered ground zero with approximately 7,000 acres of native marsh now displaced. These dense mats of grass can impede water flow in stormwater applications, and restrict usage of irrigation holding ponds and fish ponds.

How does one manage this invasive grass?

Infestation prevention can be accomplished by controlling the rhizome expansion. This is easier said than done, as a small rhizome fragment left behind will no doubt cause re-establishment. Keeping the infestation at bay, by controlling the spread at waterways is key.

For IPM (integrated pest management) solutions follow these steps:

For cultural management, invasive plants tend to quickly establish in open or recently tilled areas. So, prescribed burn and clearing by mowing are methods that tend to promote infestations. A healthy, diverse landscape with native plants, or species with non-invasive tendencies will provide a level of defense.

Mechanical control is not very effective. Tilling the land only spreads the rhizomes through fragmentation.

There are few biological controls, although cattle and goats will graze and they may continue to spread the grass.

Chemical control using Glyphosate (Roundup, etc.) at a 2-3% solution and imazapyr (Arsenal, Chopper or Habitat) at 0.5 to 1 % solution has been effective for on land use. Aquatic herbicides with glyphosate (Rodeo, etc.) are effective for ponds. This can be applied in a liquid or granular form. A non-ionic surfactant will be needed to adhere the liquid chemical with success. Keep in mind, these herbicides are systemic, meaning they are absorbed and move through out the plant tissue. Be sure to minimize over spray damage of desirable plants, especially related to drift. Imazapyr also has longer soil activity and could impact sensitive oaks. Torpedograss is much more difficult to treat in water and will require multiple applications to completely control whether in water or on land.

For more information on torpedograss, contact your local county extension office.

Information for this article provided by the UF/IFAS Center for Aquatic and Invasive Plants:  https://plants.ifas.ufl.edu/plant-directory/panicum-repens/ and the Wetlands Weeds Journal article “Torpedograss – Forage Gone Wild” by Ken Langeland & Brian Smith of UF/IFAS and Charles Hanlon of the South Florida Water Management District: https://www.se-eppc.org/wildlandweeds/pdf/su98-langeland-p4-6.pdf

UF/IFAS Extension is an Equal Opportunity Institution.

Aquatic Weed Control – Common Salvinia

Aquatic Weed Control – Common Salvinia

Common Salvinia Covering Farm pond in Gadsden County
Photo Credit – Shep Eubanks UF/IFAS Gadsden County Extension

Close up of common Salvinia
Photo Credit – Shep Eubanks UF/IFAS Gadsden County Extension

Aquatic weed problems are common in the panhandle of Florida.  Common Salvinia (Salvinia minima) is a persistent  invasive weed problem found in many ponds in Gadsden County. There are ten species of salvinia in the tropical Americas but none are native to Florida.  They are actually floating ferns that measure about 3/4 inch in length.  Typically it is found in still waters that contain high organic matter.  It can be found free-floating or in the mud.  The leaves are round to somewhat broadly elliptic, (0.4–1 in long), with the upper surface having 4-pronged hairs and the lower surface is  hairy.  It commonly occurs in freshwater ponds and swamps from the peninsula to the central panhandle of Florida.

Reproduction is by spores, or fragmentation of plants, and it can proliferate rapidly allowing it to be an aggressive invasive species. When these colonies cover the surface of a pond as pictured above they need to be controlled as the risk of oxygen depletion and fish kill is a possibility. If the pond is heavily infested with weeds, it may be possible (depending on the herbicide chosen) to treat the pond in sections and let each section decompose for about two weeks before treating another section. Aeration, particularly at night, for several days after treatment may help control the oxygen depletion.

Control measures include raking or seining, but remember that fragmentation propagates the plant. Grass carp will consume salvinia but are usually not effective for total control.   Chemical control measures include :carfentrazone, diquat, fluridone, flumioxazin, glyphosate, imazamox, and penoxsulam.

For more information reference these IFAS publications:

Efficacy of Herbicide Active ingredients Against Aquatic Weeds

Common salvinia

For help with controlling Common salvinia consult with your local Extension Agent for weed control recommendations, as needed.