Air potato (Dioscores bulbifera) is a perennial, herbaceous self-twining vine that can grow over 60 feet in length, enabling it to climb over and smother many native plants. The Florida Exotic Plant Pest Council (FLEPPC) lists air potato as a Category 1 invasive plant, which means that it has disrupted natural communities and ecological functions by displacing native plant species.
In 2012, a leaf feeding beetle (Lilioceris cheni) was introduced into South Florida from China for biological control of air potato. Although it is too early to determine any potential long-term impacts, the initial results have been promising. The larvae and adults of the air potato leaf beetle feed on the leaf tissue and occasionally the bulbils. The damage to the growing tips of the plant have dramatically reduced its ability to cover native vegetation. Extensive damage to air potato was evident within three months after the first release. Additionally, testing by scientists at the USDA/ARS Invasive Plant Research Laboratory in Fort Lauderdale concluded that the beetle will not complete development on any other plant found in Florida.
Air potato beetle up close. Photo by Julie McConnell
The female air potato leaf beetle lays an average of 1,200 eggs, which develop into larvae in about four days. The young beetles skeletonize the air potato leaves for the next eight days and then pupate into foam-like cocoons. Clumps of cocoons fall to the ground and the adult beetles emerge 13 to 16 days later. There can be a new generation of air potato leaf beetle every month while the weather is warm. For the winter, the adults hide in leaf litter and wait for spring.
The question now is: “How well will they survive through a longer, colder Northwest Florida winter?”. USDA scientists, UF Extension agents and citizen scientists in Bay and Okaloosa County hope to find out. Earlier this month, June 2015, air potato leaf beetles from the Hayslip Biological Control and Research and Containment Laboratory in Ft. Pierce were released into areas containing air potato. They will be monitored over the next year. Look for an update this coming summer.
Immature TSA fruit are resemble tiny watermelons. Mature fruit turn yellow and contain 40-50 seeds each. Photo credit: UF Hayslip Biological Control Research and Containment Laboratory
Florida ranchers know Tropical Soda Apple (TSA) as the “Plant from Hell”. It was first noticed in south Florida, but its seeds survive in the digestive tract of animals and it spread north through the movement of hay and cattle. TSA plants are covered with thorns and can make large sections of pasture nearly useless for livestock. Concerted efforts to lessen the population of TSA since its arrival have reduced the populations in pastures but it persists in sheltered or waste locations. Cattle, birds, deer and feral hogs ingest the mature fruits and spread the plants to loafing and browsing areas that may be inaccessible to mechanical treatment with anything larger than a hoe. According to Dr. Jeff Mullahey, who has been working on TSA since its appearance in south Florida, one plant can produce 40,000-50,000 seeds with seed germination ranging from 75%-100%. The seeds remain viable for at least three years. Be on the lookout for these while engaged in outdoor activities.
Isolated plants can be controlled by mechanical means. You won’t want to pull them up barehanded, though. Additional information and control methods are available at http://edis.ifas.ufl.edu/uw097, or contact your local Extension agent.
The rounded seedling leaf in the foreground has few spines, but all the later leaves do have them. Photo by Jed Dillard
Five tiger shrimp captured by shrimpers in Pensacola Bay.
Giant Tiger Prawn (Penaeus monodon):
This catchy phrase coined by Robert Turpin (Escambia County Marine Resources Division) describes a recent invader to our marine waters in the past decade. Many coastal residents are aware of the invasive lionfish that has invaded our local reefs but less have probably heard of the Asian Tiger Shrimp. This member of the penaeid shrimp family, the same family are ediblewhite, brown, and pink shrimp come from, was brought to the United States in the 1960’s and 70’s as an aquaculture project. Over the years farmers have moved from Tiger Shrimp to the Pacific White Shrimp and the last known active farm was in 2004.
The Asian Tiger Shrimp can reach lengths of 12″
In 1988, two thousand of these shrimp were lost from a farm in South Carolina during a flood event. Only 10% of those were recaptured and some were collected as far away as Cape Canaveral. No more was heard from this release until 2006 when 6 were captured; one of those in Mississippi Sound near Dauphin Island. Each year since the number of reported captures has increased suggesting they are breeding.
In the Panhandle, one individual was caught in 2011 near Panama City and 5 were collected in 2012 in Pensacola Bay. They have been found in all Gulf coast states and there has been at least 1 record in each of the Florida Panhandle counties. The future impact of this shrimp to our area is still unknown but they have a high tolerance for salinity change and consume many types of benthic invertebrates. Tiger shrimp may out compete our native penaeid shrimps and could possibly feed directly on the juveniles. It is thought that they could possibly transmit diseases to our native shrimp.
Giant Tiger Prawn: This large shrimp, also known as the Asian Tiger Shrimp and the Black Tiger Shrimp, can reach lengths between 8-12 inches. It resembles are native edible penaeid shrimp but differs in that it has distinct black and yellow stripes.
NOAA scientists are interested in obtaining samples of this shrimp for DNA studies. It differs from other local penaid shrimp in that it is larger (8-12” long), dark in color (dark green to black) and has light stripes (white to cream colored). The larva and juveniles live in the bay. Sub adults will migrate offshore for breeding. They are a tropical species that have a low tolerance for cold temperatures, showing no growth below 20°C. If you think you have found one of these shrimp, record size location (GPS preferred), and email information to ExoticReports@MyFWC.com. You can also report to EDDMapS using the website or I’ve Got One! phone app. To learn more about Tiger Prawns view the USGS factsheet.
The nonnative Giant Tiger Prawn – also known as the Black Tiger Shrimp. Photo by David Knott, Bugwood.org
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
Both ferns reproduce and spread readily by wind-blown spores. Animals, equipment, and even people that move through an area with climbing ferns are very likely to pick up spores and move them to other locations on the property or even to other properties.
Japanese climbing fern is a delicate looking perennial climbing vine. It is capable of forming a dense mat-like thatch capable of covering trees and shrubs. Initially, it was introduced from Japan as an ornamental. It is scattered throughout the lower portions of Alabama, Georgia, Louisiana, South Carolina, and south into central Florida. Further planting or cultivation of this vine is prohibited by the Florida Department of Agriculture and Consumer Services.
Old World climbing fern has been a problem for many years in central and south Florida but it is currently moving north. The northern edge of its advance is now just south of Marion County.
Adequate control of both climbing ferns has been achieved with multiple applications of glyphosate. Other herbicides have also been used to control Japanese climbing fern.
As with most invasive plants, repeated and correctly timed treatments are likely to be necessary.
For more information about climbing ferns contact your local UF/IFAS Extension Office and read the following publication: http://edis.ifas.ufl.edu/fr133
Northwest Florida can be a pond owner’s paradise. There is usually enough rainfall to keep ponds filled, catfish, bass, and brim are well adapted to the environmental conditions, and there is a long season to catch fish.
One of the biggest problems pond owners face is the constant struggle with pond vegetation. Some pond vegetation is good. It provides a cover for young fish, helps stabilize the shoreline or bank, and some vegetative species are attractive wildlife.
However some species are highly invasive and can completely overtake a pond. One such species is water hyacinth (Eichhornia crassipes).
The water hyacinth is a floating plant, which if left unchecked and allowed to grow to its maximum potential, can weigh up to 200 tons per acre of water. In rivers, it can choke out other vegetation and make navigation difficult to impossible.
Water hyacinth, as an ornamental plant, is a wolf in sheep’s clothing. The plants intertwined and form huge floating mats which can root on muddy surfaces, as seen in the photo below.
The plant will be several inches tall, has showy lavender flowers, with rounded, shiny, smooth leaves. These leaves are attached to spongy stalks that help keep the plants afloat. The prolific roots are dark and feathery.
In Northwest Florida this pest commonly dies back in the winter. Unfortunately it is able to regrow when the weather and water warm.
Water hyacinth is not a native species. It is believed to have been introduced into the U.S. in 1884 at an exposition in New Orleans. Within 70 years of reaching Florida, the plant covered 126,000 acres of waterways (Schmitz et al. 1993).
Water hyacinth is on the FL DACS Prohibited Aquatic Plant List – 5B-64.011. According to Florida Statute 369.25, “No person shall import, transport, cultivate, collect, sell, or possess any noxious aquatic plant listed on the prohibited aquatic plant list established by the department without a permit issued by the department.”
To control a small infestation, the plants can be gathered from the surface, brought to the shore, left to dry and then disposed of in the garbage. There are biological control options—water hyacinth weevils will be useful in keeping the plant populations down.
The spongy petiole helps keeps the plant afloat.
Finally, chemical herbicide options may be the best alternative. University of Florida Aquatic Vegetation Specialist, Dr. Langeland, wrote Efficacy of Herbicide Active Ingredients Against Aquatic Weeds, a good publication that will help you to determine which herbicide will work best for different weeds.
NOTE: The middle of the summer is generally not the ideal time for applying herbicide on pond vegetation. For more information on weed control in Florida ponds, please see Weed Control in Florida Ponds. If you have any questions about identifying a pond weed, contact your local county Extension agent.
This yard on Pensacola Beach has become over run by vitex. Photo courtesy of Rick O’Connor.
In 2013 we began writing about a potential invasive plant in the Florida panhandle called Beach Vitex (Vitex rotundifolia). The first record we knew of was reported from Pensacola Beach and was posted on EDDmaps.org. According to this website only two other records had been found in Florida, both in the Jacksonville area. It did not seem like a real problem and was not listed as an invasive species in the state. But I decided to survey Pensacola Beach and see if the plant might be growing in other places – it was – in 22 other places!
Based on the severe problems they have had with this plant in coastal communities of North and South Carolina, and the fact that more records were coming in of the plant in northeast Florida, both the Florida Exotic Pest Plant Council and the University of Florida / IFAS Center for Aquatic and Invasive Plants listed the plant as “invasive – not recommended”.
So is the plant a problem?
In the Carolina’s it certainly is. Used in dune restoration projects it quickly became a monoculture and displaced many species of native dune plants – including sea oats. It grows aggressively in the summer months, crossing bike paths and driveways and can extend towards the water impeding sea turtle nesting. One fear is that the plant will grow fast enough that a turtle nest will become overwhelmed by the plant before the eggs hatch, in a sense entrapping them. The plant produces a large tap root and extends above ground stolon in all directions. I have measured stolon over 20 feet in length and many secondary roots extending from these. Stolon extending from nearby vitex can form an intermingle mess of vines that can be very difficult to remove.
Another issue is the taproot. Most are small and manageable but we have measured some 3-4” in diameter and one, on Pensacola Beach, was about 10” in diameter. Once they reach this size removing becomes very difficult, if not impossible. The key is to identify and remove the plant early. It has become such a problem in the Carolina’s that a state task force has been created to address it.
So where does this plant stand in the Florida Panhandle?
Since the initial survey conducted on Pensacola Beach the plant has been found on 21 properties on Pensacola Beach itself and 1 property on Perdido Bay (both in Escambia County). It has been verified at two locations within the Naval Live Oaks Reservation within Gulf Islands National Seashore in Santa Rosa County. A survey of Perdido Key in 2015 found no evidence of the plant – but the Key will be surveyed again in 2016. As for coastal counties to the east – we are not sure.
This maybe one invasive plant we may be able to manage before it gets too far out of control.
(If you live in a coastal county between Pensacola and Aucilla River, and believe you may have the plant, please contact your local Extension Office to let them know. We would like to log the occurrence on EDDmaps and can provide advice to the property owner on how to safely remove it).
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