by Rick O'Connor | Feb 28, 2022
In recent years this question has come up more often. With the thousands of different invasive species taking over the landscape and waterways why are we spending so much time, money, and resources battling them when you are not going to win? It’s a fair question honestly and one that is the theme of the 2016 book The New Wild by science writer Fred Pearce.
The argument that Pearce makes is that life on our planet has worked under the premise that the stronger survive and pass on their genes to the next generation since the beginning of time. They compete with other species for space and resources and those best adapted will win out. If these invasive species are winning out, that is how nature intended it to be and that we should get use to the “new wild”.
Under this thought the forest of the southeastern United States would hold more Chinese tallow and cogongrass than it once did, and the reefs of the Gulf of Mexico would be home to a new species called the lionfish. Again, the thought makes sense and indirectly may be growing.
I say that because there are many who cannot euthanize an animal, no matter who it is or where it came from. There is a growing call to not euthanize them because it is wrong, and even some cases with green iguanas where rescues, and releases, from the cold are now occurring. There are some who found economic ways to benefit from some invasive species, lionfish dinners and Chinese tallow honey, and do not necessarily want to remove them. So, maybe these nonnative species are not all that bad.
So, why should we be concerned about them?
Why should spend the time, money, and effort to manage them (euthanizing when needed)?
Well, by using the definition accepted by the University of Florida IFAS Extension, they are bad. This definition states (1) invasive species are non-native to the area, (2) they arrived via humans (whether intentional or accidental), and (3) they are causing an economic and/or environmental problem. Lowering your quality of life has also been connected to a “problem”. And if it is truly a problem, and it should be to have the name invasive attached, then it needs to be managed. If they are not really causing a problem, then maybe they are not really invasive.
With invasive species we typically see a nonnative who moves into a disturbed part of the environment. Being nonnative, they have few natural predators, and their reproductive dispersal of the landscape is quick and effective. They have mentioned that the dispersal rate of the lionfish was one of the greatest “invasions” ever seen. This increase in their population decreases the populations of native species and, in many cases, the overall biodiversity of the system. Biologists and naturalists understand the importance of biodiversity in maintaining a healthy ecosystem. Monocultures of any species, even in agriculture, and be dangerous when a pathogen comes along. This pathogen could wipe out the entire ecosystem. I have heard this argument before. Most of the Everglades is sawgrass, sawgrass is grass, which provides food and oxygen for the rest of the system. If herbivores only need plants to survive, and they provide food for the carnivores, does it really matter which grass it is? Grass is grass.
However, if this grass species does become threatened by a pathogen, or the herbivores do not eat such grass, then we DO have a problem. The invasion of cogongrass is a good example of this. With the serrated blades and layers of silica within, few herbivores seek this plant out. If cogongrass is allowed to take over forest and farmland, there is certainly a problem, and this plant would need management.
Deep water lionfish traps being tested by the University of Florida offshore Destin, FL. [ALEX FOGG/CONTRIBUTED PHOTO]
Lionfish is no different. There are some reefs in the northern Gulf of Mexico that have had densities of 200 lionfish/hectare or more. Some photos show only lionfish. Studies show they are like bullfrogs, consuming anything they can get into their mouths. There are at least 70 different species of small reef fishes that have been found in the stomachs of lionfish. The decrease of these small fish can impact the presence of larger, commercially sought-after species. They have also found that many of these small reef fish control algae growth on coral reefs and their decline can increase algae populations and the smothering of the coral themselves. They are indeed a problem.
We could go on and on with examples of how these species are problematic. Pythons, tegus, and Old-World Climbing Fern. There are those who cause problems in small quite ways such as the crazy ants, Cuban treefrogs, and the red fire ant.
And then there is the argument that WE, not nature, introduced this species. That is #2 of the definition. The argument that if nature introduced the species, then yes – we could except their presence as more natural and the process more natural. But nature did not introduce them – we did. This brings up the argument that the situation is more unnatural and since we “did it” we should “fix it”.
Even Pearce mentions in his book that some species need management. The argument that you are not going to win is true for some species. We are not going to eradicate Chinese tallow, cogongrass, and lionfish from Florida. However, we should be concerned about them. We should manage the locations where they currently exist and prevent the spread to new locations. In our next edition, we will discuss “how they get here” to help reduce the spread of current invasive species, and the introduction of new ones, from happening.
by Rick O'Connor | Feb 24, 2022
EDRR Invasive Species
Cane Toad (Rhinella marina)
a.k.a Bufo toad, Marine toad
The Cane Toad
Photo: University of Georgia
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:
The cane toad is native to central and south America.
Introduction:
Cane toads were intentionally released into Florida in the 1930s as a biological control for a beetle that was consuming the economically important sugar cane crop. It is believed that the initial released population did not survive but additional released toads in the 1950s did.
EDDMapS currently list 1,102 records of this toad. All but five are reported from Orlando south. Three were reported in north Florida – one in the Gainesville area, one in the Villages, and one in Deltona area. Two have been reported in the Florida panhandle. A small population existed in Bay County for a period and one report came from Okaloosa County, which is the only report within the Six Rivers CISMA. This toad is still sold in pet stores, and it is most likely these were escaped pets.
Description:
This toad is much larger than our native toads. Florida’s native toads do not reach lengths greater than 4 inches, cane toads can reach 6 inches and possibly up to 9 inches. The are reddish-brown in color and have very large parotid glands (poison glands) on their shoulders. Native toad parotoid glands are typically oval in shape, the cane toads are triangular. The cane toad also possesses a ridged crest over the eye that our native toads lack.
Even in their native range, cane toads prefer human habitations and are often found around homes, gardens, schools, and in agriculture fields.
Issues and Impacts:
There are two primary concerns with this toad. (1) their voracious appetite, and (b) their toxicity to pets. Cane toads will feed on native frogs, lizards, snakes, small mammals, and anything else they can get into their mouths. In areas where cane toads are common, declines of the native southern toads have been reported. The poison secreted by this toad is highly toxic to pets. Though in most cases there is a lot of foaming and drool at the mouth, dogs have had seizures and have gone into cardiac arrest, even dying. The eggs and tadpoles of this toad are also toxic. Eggs laid in landscaped ponds typically kill the fish that inhabit them. The toxin is also highly irritable to humans. Wiping on the face or open cuts can lead to skin irritations and everyone should avoid wiping their eyes. It is recommended to handle these toads with gloves.
Management:
Hand capturing, using gloves, and humanely euthanizing cane toads found in your yard is the primary method of control. It is important to correctly identify the toad before euthanizing it. If you have questions, you can contact your county extension office.
To humanely euthanize wipe, or spray, benzocaine or lidocaine on the lower belly. This will act as an anesthesia to numb the nervous system and put the animal to sleep. The toad can now be placed in a zip lock bag and placed in the freezer. If you do not have products with benzocaine or lidocaine (often found in products to help with toothache or sunburns) you can place the toad in a zip lock bag for a few hours in the refrigerator, then move to the freezer. It is recommended if cane toads are present in your neighborhood to remove outdoor pet food and water bowls. If you do not wish to euthanize the toad you can contact a wildlife control business.
Please report any sighting to www.EDDMapS.org. There are biologists who verify the photograph you send. It is important that we keep track of this EDRR species.
For more information on this EDRR species, contact your local extension office.
References
Johnson, S. 2020. Florida’s Frogs and Toads. University of Florida Department of Wildlife Ecology. https://ufwildlife.ifas.ufl.edu/frogs/canetoad.shtml.
Wilson, A., Johnson, S. 2021. The Cane or “Bufo” Toad (Rhinella marina) in Florida. Electronic Data Information System publication #WEC387. https://edis.ifas.ufl.edu/publication/UW432.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Rick O'Connor | Feb 18, 2022
Six Rivers “Dirty Dozen” Invasive Species
Japanese Honeysuckle (Lonicera japonica)
Japanese Honeysuckle
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 “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 honeysuckle is native to China, Japan, and Korea.
Introduction:
Japanese honeysuckle was first introduced to Florida in 1875 for agricultural and gardening purposes. It was introduced as a forage plant in the agriculture industry and was very popular as a landscape plant due to its beautiful showy flowers. Its invasive nature was quickly discovered and is now listed as a Category I invasive plant and a Florida noxious weed.
EDDMapS currently has 115,101 records of this plant across the country. Most are east of the Mississippi River but cover the entire east coast, including New England. There are records in the southwestern part of the U.S. In Florida, most of the records are in the northern part of the state, particularly in the panhandle. There are few records south of Orlando. Within the Florida panhandle there are 1,558 records and 1,209 within the Six Rivers CISMA. As with most species, this is probably underreported.
Description:
Japanese honeysuckle is a woody vine that produces beautiful white flowers. These flowers have multiple sepals, and the stamens which extend outward resembling “whiskers”. The leaves are about 1-3 inches, ovate is shape, and opposite on the stem. The small fruits are green and hard when immature, black and soft when older.
Issues and Impacts:
This is an aggressive growing vine that can quickly take over the landscape. It can cover small shrubs and trees killing them, block sunlight so germination of other plants is impossible, and outcompete native plants for needed sunlight decreasing the biodiversity within the area.
Management:
Removing by hand or shovel is effective on small patches. Mowing small patches has found to reduce seed spread but the parent plant may return with additional stems. Mechanical tillage can be effective but can enhance seed dispersal from the seed bank and is not always an option in some locations.
Chemical treatment with either glyphosate or triclopyr has been effective however, cut stump application is recommended. Foliar sprays that do not reach ALL leaves can induce resprouting.
There are no known biological controls at this time.
For more information on this Dirty Dozen species, contact your local extension office.
References
Japanese Honeysuckle. University of Florida IFAS Center for Aquatic and Invasive Plants
https://plants.ifas.ufl.edu/plant-directory/lonicera-japonica/.
Lonicera japonica. University of Florida IFAS Assessment. https://assessment.ifas.ufl.edu/assessments/lonicera-japonica/.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Rick O'Connor | Feb 11, 2022
EDRR Invasive Species
Natal grass (Melinis repens)
Natalgrass
Photo: University of Florida IFAS
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:
South Africa
Introduction:
Intentionally introduced as a forage plant but lacks the nutritional value of other introduced forage plants.
EDDMapS currently list 3,923 records of this plant, all are across the southern United States from California to Florida. 3,591 reports are from Florida itself, with 53 of these in the Florida panhandle, and 31 of those within Six Rivers CISMA.
Description:
This reddish colored grass can cover large areas of open fields. The reddish color comes from the hair-like structures that are associated with the flowers and will become gray with age. The flowers themselves are a pink-purple in color and are produced from panicles (a cluster of small flowers) that are 4-8 inches long. The grass can reach a height of 40 inches and dispersal is by wind blown seeds.
Issues and Impacts:
It aggressively grows in open fields and displaces native grass species from these areas. Many of which are important to local ecology.
Management:
Hand removal of small patches can be effective, but the property owner should be aware of the ease of seed dispersal when doing this, it is recommended to remove prior to going to seed. It tends to quickly invade open areas of disturbance including the use of fire. Mowing does not provide control.
The herbicides glyphosate and imazapyr have shown to have good control but must be used prior to going to seed. Both herbicides are non-selective, and care must be taken not to treat native plants. Imazapyr has a longer soil life and replanting the area after treatment may not be effective for several months.
There are no known biological controls at this time.
If you are in the Florida panhandle area and believe you may have natal grass, please contact your county extension office to let them know as well as 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
University of Florida IFAS Center for Aquatic and Invasive Plants. Natal Grass. https://plants.ifas.ufl.edu/plant-directory/melinis-repens/.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Danielle S. Williams | Feb 3, 2022
Air Potato Leaf Beetle
I’m sure many of you could easily recognize air potato with its winding vines and heart-shaped leaves climbing high along roadsides, fencerows and natural vegetation, but could you recognize its key predator, the air potato leaf beetle? Believe it or not, a small, red leaf-feeding beetle was introduced and is here to help control the invasive air potato vine!
The Issue with Air Potato Vine
Air potato (Dioscorea bulbifera) is a plant species that is native to Asia and was first introduced to the United States as a landscape plant but has now become one of Florida’s most problematic invasive plants. Air potato has spread to 60 of the 67 counties in Florida, including many in the Panhandle. Air potato vines can grow up to 8 inches per day! The dense vines smother vegetation and displace native plants, trees and animals. The air potato vine is on the Florida Noxious Weed List. This means that is illegal to plant, propagate or move the air potato unless you have a permit.
The air potato vine spreads by vegetative reproduction. This is through the formation of aerial tubers, or bulbils that are formed in the leaf axils. The aerial tubers are roundish and vary in size. In addition to aerial tubers, air potato also produces underground tubers, making control that much more difficult. During the winter, the aerial tubers will drop to the ground and give rise to new vines in the spring.
Park managers and homeowners throughout Florida have battled with the air potato as its covered our landscape. For years, the primary means of control were by manually pulling, digging and destroying the tubers or by herbicide applications, until recently.
Classical Biological Control of the Air Potato Vine
Another method for controlling invasive plants is with classical biological control. This method involves searching for insects that feed exclusively on a plant in its native range and releasing them in an area that has been invaded by the plant. Scientists with the United States Department of Agriculture discovered the air potato leaf beetle (Lilioceris cheni) that feeds on air potato in its native range of Asia. After extensive testing, scientist found that the beetle is species-specific and poses no risk to other plant species.
In 2012, air potato leaf beetles were first released in Florida to help battle the air potato. Now, according to the Florida Department of Agriculture and Consumer Services (FDACS), they are officially established in the state! This means, they are here to stay and research has shown they are helping!
While you likely won’t see the beetles now, because they are overwintering (a period of suspended development), look for them in the spring! Adults are bright red with a black head and legs and about the size of your pinky fingernail. The females lay white, pale eggs on the underside of leaves. The egg-laying process causes the leaves to curl and cup. In addition to that, larvae feed on the leaves skeletonizing them. This feeding by the beetle negatively affects the growth and reproduction of the plant.
Skeletonized leaf damage to Air Potato from the Air Potato Leaf Beetle. Photo: Danielle Sprague
For more information on air potato leaf beetles, please visit:
by Rick O'Connor | Jan 27, 2022
What is the Weed Wrangle?
It is a national event held every February where members of local communities visit a public area to remove invasive plants. However, due to COVID, we are again doing it “virtually” this year. Virtually meaning that members of the local community work in their own yards to remove invasive plants. This year in the western Florida panhandle we are targeting the Chinese tallow, but of course you are welcome to remove ANY invasive plant you may have.
The round-ish ovate leaves of the Chinese Tallow.
Photo: Rick O’Connor
How do you DO the Weed Wrangle?
Step 1 – Survey your property to see if you have any Chinese tallow. This tree is also known by many as the “popcorn tree”. You can work with other members on your street who are interested and identify Chinese tallow on your block.
Step 2 – Confirm the identification. If you are sure it is Chinese tallow, and many are very familiar with this plant and is why we have chosen it, you are good to go. If not, you can contact your county extension office for verification.
Step 3 – Report the tree(s) to the national database EDDMapS at www.EDDMapS.org. There is a “report sightings” button on the tool bar. It will ask for latitude and longitude and you can get this information from your phone or a GPS or from google earth if you have it on your computer. Remember to type in longitude as a negative number, -87 in our case, so that it is reported in the correct hemisphere. NOTE: You are not allowed to report plants on someone else’s property without their permission, please get that before you do.
Step 4 – Remove it. Please take photo of the tree(s) BEFORE you remove. Not everyone wants to remove their Chinese tallow. Even though it is an invasive species and listed as a state noxious weed. Many enjoy the tree, and the color changes it provides. There is nothing illegal about having the tree in your yard, so you are fine. If you do choose to remove it there are methods that have been tested that work best. Contact your county extension office for those methods so that you are successful. Please take photo after removal.
Step 5 – Contact me – Rick O’Connor, Escambia County Extension, at roc1@ufl.edu to let me know you which steps you completed. I am tracking participation in this years Weed Wrangle. We will be doing this during the month of February. We also can enter you into a drawing for prizes!
If there are other invasive plants on your property you are interested in removing and want to know the best methods to do so, contact your county extension office and we can provide that for you. It would certainly be included in this years Weed Wrangle.
Thanks for helping stay on top of our invasive species problem.
Members of the Six Rivers CISMA remove Chinese tallow from a city park in Pensacola.
Photo: Kristal Walsh.
