Giant Salvinia mats completely covering Bay County pond. This fast growing invasive can double in size every week! Photo by L. Scott Jackson
Matthew Phillips and Scott Jackson –
UF/IFAS Extension and Research works with many partners supporting invasive species management actions and strategies across Florida. One key partner is the Florida Fish & Wildlife Conservation Commission (FWC), Invasive Plant Management Section. FWC Biologists provide resources and expertise to address threats from Florida’s most disruptive invasive species. FWC and UF/IFAS have worked together for years. They have teamed-up to help residents make the best cost-effective management decisions to preserve unique habitats and ecosystems. Most days are filled with routine questions from land managers and pond owners but on rare occasions there are days we will never forget.
Active growing Giant Salvinia was observed growing out of the pond water on to moist soils and emerging cypress and tupelo tree trunks. Photo by L. Scott Jackson
Giant salvinia (Salvinia molesta) is an invasive free-floating aquatic fern from South America that is rarely observed in Northwest Florida. The species is on the Federal Noxious Weed List and the Florida Prohibited Aquatic Plants List. After a site visit with a pond owner, Scott Jackson, a University of Florida/IFAS Extension Agent, identified Salvinia molesta in the Bay County pond and notified the Florida Fish and Wildlife Conservation Commission’s (FWC) Invasive Plant Management Section. Their staff confirmed the identification of the specimen and a second voucher specimen was transferred to the Godfrey Herbarium at Florida State University.
Jackson reported the observation on the Early Detection and Distribution Mapping System (EDDMapS) housed at the University of Georgia’s Center for Invasive Species and Ecosystem Health. This was only the second reported occurrence of giant salvinia in Northwest Florida. It is a high control priority for the state of Florida due to its high invasive potential.
Giant salvinia has caused severe economic and environmental problems in Texas and Louisiana and in many countries including New Zealand, Australia, and South Africa. Giant salvinia grows rapidly and produces a dense floating canopy on the surface of ponds, lakes, and rivers. It aggressively spreads by vegetative fragments and thrives in slow-moving, nutrient-rich warm fresh water. Floating mats of giant salvinia shade out native submersed vegetation and degrade water quality.
Mats also impede boating, fishing, swimming, and clog water intakes for irrigation and electrical generation.1 Salvinia molesta has been listed in The World’s Worst Weeds – Distribution and Biology2 since 1977. It was recently added to 100 of the World’s Worst Invasive Alien Species, an all taxa list compiled by invasion biologists with the Global Invasive Species Database.3
The most distinguishing physical characteristic of Salvinia molesta is the basket- or egg beater-like hairs on the upper leaves (a hand lens is required) which distinguishes it from common salvinia (Salvinia minima). Common salvinia also has hairs on the upper leaf surface but they do not form basket-like structures at the tips. The upper leaves of both species repel water.
Photo by Barry Rice, sarracenia.com, Bugwood.org Rows of egg beater or light bulb shaped leaf hairs are a unique identifying characteristic of giant salvinia.
The location of the giant salvinia infestation found by Jackson is precariously close to Deer Point Lake, a 5,000 acre water body that is the main source of drinking water for Panama City and surrounding Bay County. The 2.5 acre infestation was on a 3.6 acre divided pond and both sections were treated. Treatment of the infestation was initiated by FWC in June 2013 at no expense to the property owners.
Bay County pond with no observed Giant Slavinia. Taken Oct 2013 by Derrek Fussell, FWC.
The pond continues to be monitored and, to date, there have not been any signs of living Salvinia molesta. We will continue to monitor the pond to make sure there is no re-establishment of giant salvinia. Investigations continue to try and learn more about the introduction of the pernicious species to this isolated pond.
Read more about the successful treatment regime FWC Biologists used to control giant salvinia in Northwest Florida. This was published in Florida Aquatic Plant Management Society’s publication “Aquatics” – see page 5.
WJHG 7 in Panama City ran this news story. Please see their webpage for additional information and video. “Invasive Plant Threatens Deer Point Lake“.
1 Giant salvinia (Salvinia molesta), Weed Alert, Florida Fish & Wildlife Conservation Commission, Tallahassee, FL, 2 pp.
2 The World’s Worst Weeds – Distribution and Biology. 1977 and 1991. L.G. Holm, D.L. Plucknett, J.V. Pancho, and J.P. Herberger. 609 pp.
3 Alien species: Monster fern makes IUCN invader list. 2013. Nature 498:37. G.M. Luque, C. Bellard, et al.
Matt Phillips is an Administrative Biologist with the Florida Fish & Wildlife Conservation Commission, Invasive Plant Management Section in Tallahassee; (850) 617-9430; Mattv.email@example.com Scott Jackson is a University of Florida/ IFAS Sea Grant Extension Agent, Bay County; (850) 784-6105; LSJ@ufl.edu
Air potato vine. Photo by Scott Jackson
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 edible white, 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
Japanese Climbing Fern (Lygodium japonicum) and Old World Climbing Fern (Lygodium microphyllum) are presently the only non-native invasive ferns in Florida.
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