Invasive Species of the Day: Cogongrass and	Tawny Crazy Ant

Invasive Species of the Day: Cogongrass and Tawny Crazy Ant

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Cogongrass (Imperata Cylindrica):

Cogongrass Photo Credit: Chris Evans, Illionois Wildlife Action Plan, www.bugwood.org

Cogongrass Photo Credit: Chris Evans, Illionois Wildlife Action Plan, www.bugwood.org

Cogongrass is one of the 10 worst weeds in the world.  This grass is an aggressive grower and forms colonies causing loss of productive forest areas, severe degradation of habitat, and economic issues.  Since its introduction in the 1900s, Cogongrass has spread to most of the counties in Florida.  Reproduction occurs through seed production and the creeping rhizome system.  This plant is prolific once established with the creation of a very dense rhizome system that retains water and releasing of allelopathic chemicals reducing competition from other plants.

Cogongrass is yellow/green in color with an off-set midrib and a fluffy white seed head. Cogongrass is drought and shade tolerant. Once this grass invades, it will quickly displace the native species and requires frequent and intensive controls.

Early detection is best since a small infestation is easier and cheaper to treat. The larger infestations become more time intensive, expensive, and difficult. There are treatment options for these infestations, make sure that specific instructions are followed and treatment is repeated.

For more information on the biology of this plant and various treatment options visit http://edis.ifas.ufl.edu/wg202. Also, by contacting your local UF/IFAS Extension office for assistance and information.

 

Cogongrass is a fire-adapted species, thriving where fire is a regular occurrence. In fact, the threat of wildfires greatly increases with the presence of cogongrass, a non-native invasive species. Cogongrass fires burn hotter and faster than native grass fires. This footage, shot in Baldwin County, Alabama, demonstrates how destructive a cogongrass fire can be to native vegetation.

Tawny Crazy Ant (Nylanderia  fulva):

Cleaning up large piles of dead ants are a daily cleanup chore for this homeowner. Photo: Dan Culbert, UF/IFAS Extension Okeechobee County

Cleaning up large piles of dead ants are a daily cleanup chore for this homeowner. Photo: Dan Culbert, UF/IFAS Extension Okeechobee County

Nylanderia fulva is part of the group of ants called “crazy ants” due to their erratic and quick movements.  These ants are medium to small and goldish brown to reddish brown in color.  The Tawny Crazy Ants nest in large numbers in leaf litter, soil, rotten logs, under potted plants and along underground electrical conduits.

Nylanderia fulva is a nuisance to humans.  They infest gardens, sidewalks and other areas of human traffic.  They cause damage to electrical lines.  They also displace other native ant species due to their large colony size.

This ant, Nylanderia fulva, has been confused with several other ants such as the Nylanderia pubens and Nylanderia guatemalensis.

Controlling the bug population in your garden and around your home will help decrease the likelihood of Tawny Crazy Ants invading.  Avoid transporting plant material, mulches and such to uninfested areas.  Granular baits can be used to control smaller populations but large populations will probably need a professional pest control service.

The Tawny Crazy Ant was a Featured Creature by UF/IFAS Entomology and Nematology.  Also, the UF/IFAS School IPM has some good information about controlling Tawny Crazy Ant.

Download a Coloring and Activity Book at http://edis.ifas.ufl.edu/pdffiles/IN/IN94200.pdf

Download a Coloring and Activity Book at http://edis.ifas.ufl.edu/pdffiles/IN/IN94200.pdf

For more information, contact the author Jennifer Bearden, UF/IFAS Extension Okaloosa County Agriculture Agent 850-689-5850

Beach Vitex… Is It a Growing Problem?

Beach vitex expands it's woody rhizomes aggressively; it can actually grow over sidewalks.

Beach vitex expands its woody rhizomes aggressively; it can actually grow over sidewalks and driveways.

 

It’s actually a pretty plant, this Beach Vitex (Vitex rotundifolia), and it is very good at stabilizing eroding dunes. In the 1990’s, the state of South Carolina planted this shrub to help restore dunes lost during hurricanes. It was selected because of salt tolerance, production of woody rhizomes (runners) that extend over 60 feet to trap sand, and the beautiful purple flowers that attract beneficial insects; it seemed perfect! However, folks along the Atlantic coast had no idea how invasive it would become a few years later. Residents discovered that it chokes out many of the native species such as sea rocket and sea oats producing an area of only this plant.

 

 

It is now causing problems for sea turtles. As you can see in some of these photos, the plant grows over the fore-dune, blocking access for nesting. Beach Vitex grows so aggressively that during the 60 day incubation time many turtle nests are overgrown, entrapping the hatchlings. Some have been found dead, entangled within the rhizome mats. The Beach Vitex “invasion” has become so bad that South Carolina developed a Vitex Task Force to deal with the problem.

 

 

This yard on Pensacola Beach has become over run by vitex.

This yard on Pensacola Beach has become overrun by vitex.

Is this a problem for Florida?

According to the records the Early Detection and Distribution Mapping System EDDmaps.com, Beach Vitex is distributed northward to the Chesapeake Bay area and south to Jacksonville. It is found in coastal Alabama and there is one record of the plant in Escambia County.

With so few records in Florida it is not currently listed as an invasive species in our state and there is no program set up to control it. However the Sea Grant Extension Agent in Escambia County, Rick O’Connor, was alerted in 2013 that vitex was in Gulf Breeze, Florida (Santa Rosa County) and possibly on Santa Rosa Island (Escambia County).

 

 

Please circulate to area residents to provide visual identification of Beach Vitex. Contact your Extension Office for control options and help reduce it’s impact on native species.

 

A “Wanted Poster” was developed by O’Connor to post in the coastal communities of Escambia and Santa Rosa counties to see if the plant was more common than the records indicated. At this time, six properties on Santa Rosa Island have confirmed records of Vitex and two more will be surveyed soon. The wanted poster program was published in the local newspaper which reached the east coast of Florida. Reports from that coast indicate that it has extended south into Volusia County. Okaloosa/Walton Sea Grant Agent Brooke Saari is posting the wanted poster in those counties to see if the plant has reached their coasts.

 

 

 

The owner of this yard mowed the vitex.  However the woody rhizomes are still present.  They will need to either dig this up or use mutliple chemical applications to completely remove.

The owner of this yard mowed the vitex. However the woody rhizomes are still present. They will need to either dig this up or use multiple chemical applications to completely remove.

 

Anyone along the coast of the Florida Panhandle who feels they may have this plant can contact either Rick O’Connor (850-475-5230; roc1@ufl.edu) or Brooke Saari (850-689-5850; bsaari@ufl.edu) and we can confirm identification. The plant is not currently listed as invasive in our state and removal is not required. However, based on the experience in the Carolina’s and other invasive species, if you wish to eradicate this plant doing so early is important. It is much less labor intensive and less costly when there are few plants. If you do choose to remove it please contact your local Extension office first. We can provide methods of successful removal. We would also like to photograph and log the record on EDDmaps.

Editor’s note: Rick provided all the photos in this article.