Basics

• Species not native to an area, often introduced by human transport

  • No natural predators to control pop.

  • Highly competitive (aggressive feeders or fast growers) for resources 

  • Can thrive in their non-native habitats

• R-selected generalists

  • More likely to be invasive 

  • High biotic potential & low parental care

  • Highly adaptable 

  • Diverse habitat & food needs

Invasive species to know

• Zebra Mussel

  • Transported by ship ballast water

  • Aggressive fileter feeders, eating algae many other species rely on

  • 1 million eggs/yr. 

  • Clog intake pipes

• Kudzu Vine

  • Planted to limit soil erosion in southern US

  • Grows very rapidly 

  • Outcompetes natives for sunlight; growing over them

  • No herbivore control in US

• Asian Carp

  • brought in to control algae growth in aquatic farms

  • Escaped to Mississippi river; outcompete native fish for food and space

  • Decreases fishery production & value 

• Emerald Ash Borer

  • Spread by wood packing materials of ships/planes & fire wood

  • Larvae laid in bark, eat their way into phloem

  • Disrupts tree nutrient transport, killing them

Controlling Invasives

• Invasives estimated to cost US $120 billion/year (2005 est.)

  • Lost ag. Productivity, tourism, property value decline, fishery decline, control and removal costs

• Control/Removal Methods

  • Laws preventing transport of invasives (firewood for emerald ash borer) 

    • Removal of hosts (dead ash trees for EAB)

  • Careful boat cleaning & inspection (Zebra mussels)

  • Introduction of natural predator (biological control)

    • Chinese wasps to kill emerald ash borer

  • Physical removal 

    • Hunting pythons, detaching z. Mussels, pulling plants out, cutting trees down