New Aquatic Invaders in Florida pdfs/Tuesday-pdf/pm... · New Aquatic Invaders in Florida Lyn A Gettys PhD University of Florida Center for Aquatic and Invasive Plants . Aquatic weeds

New Aquatic Invaders in Florida

Lyn A Gettys PhD

University of Florida

Center for Aquatic and Invasive Plants

Aquatic weeds in Florida

• Problems caused by aquatic weeds

• Sources of new invaders

• Characteristics of Florida waters

Long-time residents

• Waterhyacinth

• Hydrilla

• Waterlettuce

• Torpedograss

Newest invaders

• Feathered mosquitofern

• Hygrophila

• Tropical American watergrass

• Crested floatingheart

• Redroot floater

• Rotala

• Giant salvinia

Feathered mosquitofern

• Azolla pinnata

• FL relative: A. caroliniana

• Native range: Asia

• N fixation (rice)

• Federal Noxious Weed

• First sightings

• North Carolina (1999)

• Northern PB Co (July 2007)

Feathered mosquitofern

Feathered mosquitofern

A. pinnata vs. A. caroliniana

Feathered mosquitofern

• Chemical control: diquat

• Floating fern; spores move

Feathered mosquitofern

• Biological control? USDA

• Waterfern weevil (Stenopelmus rufinasus)

• On A. caroliniana in Jupiter

• Waterfern flea beetle (Pseudolampsis guttata)

• Biocontrol agent in S Africa (A. filiculoides)

Hygrophila

• Hygrophila polysperma

• FL relative: H. costata (aka H. lacustris)

• Native range: East Indies

• Aquarium plant

• Federal Noxious Weed

• First sightings

• 1945: Ohio (cultivated)

• 1965: Tampa

Hygrophila

Hygrophila

H. polysperma vs. H costata

Hygrophila

• Chemical control: few effective herbicides

• Endothall

• Flumioxazin?

• Biological control: not yet…

• Grass carp don’t like it

Tropical American watergrass

• Luziola subintegra

• FL relative: L. fluitans

• Native range: S/C America

• Accidental?

• FLEPPC Category 1

• First sighting

• S FL (Fall 2007)

Tropical American watergrass

Tropical American watergrass

♂ ♀

L. subintegra vs. L. fluitans

Tropical American watergrass

• Chemical control: glyphosate plus…

• Imazamox, imazapyr

• Surfactants

Tropical American watergrass

1 MAT: 2 qt imazamox

+7.5 pint glyphosate/A

1 MAT: 2 qt imazapyr

+ 7.5 pint glyphosate/A

Crested floatingheart

• Nymphoides cristata

• FL relative: N. aquatica

• Native range: Asia

• Aquatic plant nursery trade

• FLEPPC Category 2

• First sightings

• 1996: Collier County

• 2006: S Carolina

Crested floatingheart

Crested floatingheart

N. cristata vs. N. aquatica

Crested floatingheart

• Chemical control: few effective herbicides

• Shallow: glyphosate + imazapyr; endothall

• Deep: glyphosate + imazapyr; triclopyr + 2,4-D

• Biological control: not yet…

• Grass carp don’t like it

http://plants.ifas.ufl.edu/misc/pdfs/nymphoides.pdf

Redroot floater

• Phyllanthus fluitans

• FL relative: none

• Native range: S. America

• Aquarium plant

• Not listed…

• First sighting

• 2010: Peace River

Redroot floater

Redroot floater

Redroot floater

• Chemical control: unknown

• Diquat: some control

• Biological control: unknown

http://plants.ifas.ufl.edu/misc/pdfs/Red_Root_Floater_Weed_Alert_FWC_3-17-2011.pdf

Rotala

• Rotala rotundifolia

• FL relative: R. ramosoir

• Native range: India, SE Asia

• Aquarium plant

• FLEPPC Category 2

• First sightings

• 1996: Broward Co.

• 2002: Tuscaloosa AL

Rotala

Rotala

Rotala

• Chemical control: works well

• 2-4,D formulations

• Biological control: grass carp don’t like it

http://fl.biology.usgs.gov/Nonindigenous_Species/Rotala_rotundifolia/rotala_rotundifolia.html

Giant salvinia

• Salvinia molesta

• FL relative: none (S. minima)

• Native range: Brazil

• Aquarium plant

• Federal Noxious Weed

• First sightings

• 2000: Collier, Lee

• 2003: HI; LA, TX, CO…

Giant salvinia

Giant salvinia

S. molesta vs. S. minima

Giant salvinia

• Mechanical

• Biological control: weevil

• Cyrtobagous salviniae

Giant salvinia

• Chemical control

• Fluridone (***)

• Copper + diquat

– LA, TX: glyphosate + diquat + surfactant

http://myfwc.com/media/226483/InvasivePlants_salvinia.pdf, http://salvinia.er.usgs.gov/

Summary

• New invaders like it here…

• More likely to come

• Prevention / exclusion

• Vigilance

• Reporting

• Rapid action

New problems with old weeds

• Herbicide resistance

• Hydrilla

• Fluridone, endothall

• Landoltia duckweed

• Diquat

• Lemna

• Fluridone, diquat***

• Salvinia

• Fluridone***

Thanks to:

IFAS Extension Center for Aquatic and Invasive Plants

Questions?