by Rick O'Connor | Feb 5, 2021
EDRR Invasive Species
Cuban Treefrog (Osteopilus septentrionalis)
Cuban Tree Frog. Photo credit: Steve Johnson
Define Invasive Species: must have ALL of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define EDRR Species: Early Detection Rapid Response. These are species that are either –
- Not currently in the area, in our case the Six Rivers CISMA, but a potential threat
- In the area but in small numbers and could be eradicated
Native Range:
Cuban Treefrog is native to Cuba, Cayman Islands, and the Bahamas.
Introduction:
Accidental introduction in the 1920s most likely by container, or cargo ships.
EDDMapS currently list 1,953 records of this frog. Most are in Florida, and the majority of those in central and south Florida. However, there are records from Louisiana, Georgia, Tennessee, New York, and Massachusetts. Again, most likely cause of spread is hitchhiking on trucks carrying ornamental plants from nurseries in south Florida.
Within our region there are 15 records. 4 in Pensacola Bay area, 3 in Panama City Bay area, 3 from the Tallahassee area, 2 from Crawfordville, and one record from each Crestview, Marianna, and Blountstown.
There is a report of a breeding colony in the Panama City area that has not been confirmed.
There are five records within Six Rivers CISMA. Four in the Pensacola Bay area and one in Crestview.
Description:
Cuban treefrogs are first, treefrogs. Treefrogs can be identified by their large toepads used to hold on to trees and buildings. Cuban treefrog toepads are relatively larger than the native treefrogs.
Adults are much larger than native treefrogs. Local frogs will range from 1-4” but Cuban Treefrogs can reach 6”. They have rough-warty skin, but colors vary greatly. There are usually patterns of dark markings on body, but they do not have the distinct spots of the Barking treefrog. There is a yellowish color where the front and hind legs meet on the body. The eyes can be large and “bugged-out” in appearance.
The most likely native to confuse it with is the Copes gray treefrog. Both have varied colors and warty skin. Both of have the yellow color on skin near where legs join the body. However, the Copes gray treefrog will have a light-colored blotch below each eye. Also, they do not reach the large size of the Cuban treefrog.
Juveniles can be distinguished from natives by having a blueish hue to the color of their skeleton when observed from the belly side of the animal.
Issues and Impacts:
Being larger, the Cuban treefrog has been documented as a major predator of at least five species of native frogs. It is also known to consume small native lizards and snakes. The tadpoles of the Cuban treefrog have been found to out compete those of many native frogs in natural waterways.
Once in the yard, they can form very dense populations that have caused problems with “frogs everywhere”, calling at night (their calls sound like a squeaking door), and invading small ponds, water features, and swimming pools. They like to adhere to walls near lights at night to catch insects and can leave nasty stains on walls and windows. They have been known to take over bird and butterfly houses.
Once inside of the house, they can enter pipes and vents creating clogs and enter the bathroom via the toilet. They have been known to hide in electric panels and are large enough to short-circuit systems causing power outages, air conditioning, and water pump issues.
They are poisonous. And though there are no deaths attributed to them, they can cause an itching-burning sensation in people that can last over an hour. They have caused some pets to go into seizures and foam at the mouth, but no deaths have been reported.
Management:
First you must find them. Being primarily nocturnal, Cuban treefrogs will climb high into trees and spend the daylight hours awaiting sunset. They can crawl into gaps in the wall, under boards and structures, in bird and butterfly houses. One method of capture is to place 3’ sections of 1.5” PVC pipe into the ground near walls where treefrogs gather at night. Many species of treefrogs will use these pipes as hiding places during daylight hours. If there are frogs in the PVC, you can cover the top with a plastic sandwich bag, pull from the ground holding the bottom of the pipe closed with your hand. Have a partner use a stick, or broom handle, and force frogs into the bag. Once there, you can identify them.
If you have a Cuban treefrog (see identification above) there are two methods recommended to euthanize them. 1) You can zip the sandwich bag closed and place in the refrigerator for 3-4 hours. This cooling will numb their nervous system. The bag can then be transferred into a freezer for 24 hours and which time the animal is now dead. 2) Place a 1” strip of benzocaine along their back. Rub this in and wait for the animal to become numb. You can now place back into the bag and into a freezer for 24 hours. REMEMBER, WASH YOUR HANDS AFTER HANDLING A CUBAN TREEFROG. IF YOU GLOVES, WEAR THEM.
It is important to make sure you have identified the frog correctly before euthanizing it. If you have questions, contact your county extension office and have good photos of the animal. If you are in the Florida panhandle area, and it is a Cuban treefrog, please contact your county extension office to let them know and report the siting to www.EDDMapS.org. If you have questions on how to do this, your county extension office can help.
For more information on this EDRR species, contact your local extension office.
References
Invasive Cuban Treefrogs in Florida. Dr. Steve Johnson. University of Florida Department of Wildlife Ecology and Conservation.
https://ufwildlife.ifas.ufl.edu/cuban_treefrog_inFL.shtml.
Cuban Treefrog (Osteopilus septentrionalis) in Florida. Dr. Steve Johnson. University of Florida Department of Wildlife Ecology and Conservation. UF IFAS Extension EDIS publication #WEC218.
https://edis.ifas.ufl.edu/uw259.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Rick O'Connor | Jan 22, 2021
Continuing our monthly series of invasive species articles – this week we look at the first of the “Dirty Dozen”. The Dirty Dozen are the 12 worst, most problematic, established invasive species within the Six Rivers CISMA – as decided by the members of the Six Rivers CISMA. This month we look at the Japanese Climbing Fern (Lygodium japanicum).
Japanese Climbing Fern can quickly cover natural vegetation. Spores and small plants can be potentially transported in pine straw. Climbing ferns are a problem for managed timber and home landscapes. Photo by L. Scott Jackson
Define Invasive Species: must have all of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define “Dirty Dozen” Species:
These are species that are well established within the CISMA and are considered, by members of the CISMA, to be one of the top 12 worst problems in our area.
Native Range:
Japanese Climbing Fern is from eastern Asia.
Introduction:
The plant was introduced by humans intentionally in the 1930s as an ornamental plant.
EDDMapS currently list 28,649 records of this plant. Most are in the coastal states of the southeastern U.S.
Within our CISMA there are 3148 records. This is CERTAINLY underreported.
Description:
Japanese Climbing Fern is vine that grows from rhizomes below the ground. The stems and rhizomes are very thin and wire like. The leaves can be flat and finger-like to “lacey” and “feather-like” and are opposite on the vine. The broader leaves carry the sporangia housing the spores. The spores are very tiny and can be carried by the wind and by your clothes. The vines will develop massive thick mats covering fences, sides of buildings, and much of the native vegetation in the area. In winter the vines, and leaves, appear brown and dead, but they are not. It grows well in sun or shade, damp areas that have been disturbed but grows just as well in areas that have not been disturbed.
Issues and Impacts:
This plant forms massive dense mats that can completely cover all native vegetation in the area. This matting can reduce sunlight to existing plants and reduce their ability to germinate seedlings. The vines are known to grow as high as 90 feet into the tree canopy. The plant has been a problem for the timber industry trying to collect pine straw for sale. It was listed as a Florida Noxious Weed in 1999.
Management:
Hand removal, or any other means of mechanical removal, has not been effective.
Burning does kill the above ground biomass, but the below ground biomass usually returns the plant.
Puccinia lygodii, a rust found on many species of Lygodium, may be a biological control. Studies on this continue.
Chemical treating with a 2-3% solution of Glyphosate has been effective.
Any management of this plant should be done in the late summer/early fall when the spores are not present.
For more information on this EDRR species, contact your local extension office.
References
Japanese Climbing Fern, University of Florida IFAS Center for Aquatic and Invasive Plants
https://plants-archive.ifas.ufl.edu/plant-directory/lygodium-japonicum/
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Rick O'Connor | Jan 13, 2021
EDRR Invasive Species
Eurasian Milfoil (Myriophyllum spicatum)
Eurasian milfoil.
Photo: University of Florida
Define Invasive Species: must have all of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define EDRR Species: Early Detection Rapid Response. These are species that are either –
- Not currently in the area, in our case the Six Rivers CISMA, but a potential threat
- In the area but in small numbers and could be eradicated
Native Range:
Eurasian milfoil is native to Eurasia and north Africa.
Introduction:
There are two records of its possible introduction.
- Introduced accidentally in ship ballast entering the Chesapeake Bay in the late 1800s.
- Intentionally introduced in the Chesapeake Bay area in 1942.
EDDMapS currently list 20,532 records of this plant. Most are along the U.S. Canadian border.
Within our region there are 24 records. 11 in Bainbridge GA, one in Panama City, four in Apalachicola, and seven in south Alabama.
There are five records within Six Rivers CISMA, all in the Mobile delta.
Description:
Eurasian milfoil is a submerged, rooted, freshwater plant preferring slow moving waters.
It has long slender stems that are reddish-brown to whiteish-pink in color branching as it reaches the surface. The leaves are olive-green in color, less than 2” in length, and branching (feather-like). Leaf whorls along the stem are between 3-6 leaves but typically 4. Whorl nodes are 3/8” apart.
Flowers are reddish and attached to emersed spikes reaching above the water. The spike is about 8” long and the flowers are arranged in a whorl pattern around this. In Canada it flowers in late July and early August.
It can tolerate salinities up to 10 ppt and could be found in upper brackish systems.
The plant can grow in 20 feet of water but is most often found in waters less than 10 feet deep.
It can grow into large, dense mats, and can be the most common plant in the area.
Issues and Impacts:
Has been known to stop boat traffic.
Can completely cover the surface of the water reducing oxygen exchange and light for other submerged plants. Decaying mats can reduce dissolved oxygen even further.
Has been reported to negatively impact fish and birds.
Management:
Mechanical harvesters and chopping machines have been used but fragments can re-sprout.
Underwater vacuuming has been tried in Canada.
In bodies of water where this can be done, water draw down has been effective.
Biological controls using fish and insects have had some success.
Aquatic herbicides have been used to help control but rarely eradicate the plant completely.
EDUCATE BOATERS TO CHECK THEIR BOATS AND TRAILERS WHEN ENTERING AND LEAVING WATER BODIES WHERE EURASIAN MILFOIL MIGHT EXIST.
DO NOT DISCHARGE UNWANTED AQUARIUM PLANTS INTO LOCAL WATERWAYS.
It is currently not listed as a federal noxious weed and continues to be sold as a plant for aquariums.
For more information on this EDRR species, contact your local extension office.
References
Eurasian milfoil, University of Florida IFAS Center for Aquatic and Invasive Plants
https://plants-archive.ifas.ufl.edu/plant-directory/myriophyllum-spicatum/
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Daniel J. Leonard | Nov 18, 2020
The native Florida landscape definitely isn’t known for its fall foliage. But as you might have noticed, there is one species that reliably turns shades of red, orange, yellow and sometimes purple, it also unfortunately happens to be one of the most significant pest plant species in North America, the highly invasive Chinese Tallow or Popcorn Tree (Triadica sebifera).
Chinese Tallow fall foliage. Photo courtesy of Daniel Leonard.
Native to temperate areas of China and introduced into the United States by Benjamin Franklin (yes, the Founding Father!) in 1776 for its seed oil potential and outstanding ornamental attributes, Chinese Tallow is indeed a pretty tree, possessing a tame smallish stature, attractive bark, excellent fall color and interesting white “popcorn” seeds. In addition, Chinese Tallow’s climate preferences make it right at home in the Panhandle and throughout the Southeast. It requires no fertilizer, is both drought and inundation tolerant, is both sun and shade tolerant, has no serious pests, produce seed preferred by wildlife (birds mostly) and is easy to propagate from seed (a mature
Chinese Tallow tree can produce up to 100,000 seeds annually!). While these characteristics indeed make it an awesome landscape plant and explain it being passed around by early American colonists, they are also the very reasons that make the species is one of the most dangerous invasives – it can take over any site, anywhere.
While Chinese Tallow can become established almost anywhere, it prefers wet, swampy areas and waste sites. In both settings, the species’ special adaptations allow it a competitive advantage over native species and enable it to eventually choke the native species out altogether.
In low-lying wetlands, Chinese Tallow’s ability to thrive in both extreme wet and droughty conditions enable it to grow more quickly than the native species that tend to flourish in either one period or the other. In river swamps, cypress domes and other hardwood dominated areas, Chinese Tallow’s unique ability to easily grow in the densely shaded understory allows it to reach into the canopy and establish a foothold where other native hardwoods cannot. It is not uncommon anymore to venture into mature swamps and cypress domes and see hundreds or thousands of Chinese Tallow seedlings taking over the forest understory and encroaching on larger native tree species. Finally, in waste areas, i.e. areas that have been recently harvested of trees, where a building used to be, or even an abandoned field, Chinese Tallow, with its quick germinating, precocious nature, rapidly takes over and then spreads into adjacent woodlots and natural areas.
Chinese tallow seedlings colonizing a “waste” area. Photo courtesy of Daniel Leonard.
Hopefully, we’ve established that Chinese Tallow is a species that you don’t want on your property and has no place in either landscapes or natural areas. The question now is, how does one control Chinese Tallow?
- Prevention is obviously the first option. NEVER purposely plant Chinese Tallow and do not distribute the seed, even as decorations, as they are sometimes used.
- The second method is physical removal. Many folks don’t have a Chinese Tallow in their yard, but either their neighbors do, or the natural area next door does. In this situation, about the best one can do is continually pull up the seedlings once they sprout. If a larger specimen in present, cut it down as close to the ground as possible. This will make herbicide application and/or mowing easier.
- The best option in many cases is use of chemical herbicides. Both foliar (spraying green foliage on smaller saplings) and basal bark applications (applying a herbicide/oil mixture all the way around the bottom 15” of the trunk. Useful on larger trees or saplings in areas where it isn’t feasible to spray leaves) are effective. I’ve had good experiences with both methods. For small trees, foliar applications are highly effective and easy. But, if the tree is taller than an average person, use the basal bark method. It is also very effective and much less likely to have negative consequences like off-target herbicide drift and applicator exposure. Finally, when browsing the herbicide aisle garden centers and farm stores, look for products containing the active ingredient Triclopyr, the main chemical in brands like Garlon, Brushtox, and other “brush/tree & stump killers”. Mix at label rates for control.
Despite its attractiveness, Chinese Tallow is an insidious invader that has no place in either landscapes or natural areas. But with a little persistence and a quality control plan, you can rid your property of Chinese Tallow! For more information about invasive plant management and other agricultural topics, please contact your local UF/IFAS Extension office!
References:
Langeland, K.A, and S. F. Enloe. 2018. Natural Area Weeds: Chinese Tallow (Sapium sebiferum L.). Publication #SS-AGR-45. Printer friendly PDF version: https://edis.ifas.ufl.edu/pdffiles/AG/AG14800.pdf
by Rick O'Connor | Jul 2, 2020
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.
