Introduction

Invasive Species Defined

What's Being Done

 National Invasive Species Information Center

Submodule 4: Invasive Insects

Methods of Control

The primarily methods of combating invasive insects are chemical, biological and mechanical control. Let’s look more closely at each one with examples:

• Chemical – Several different chemicals are available for insect control and eradication. Spraying is probably the most common delivery method. Often, insects are “baited” to congregate in an area and then sprayed in concentrated groups. Some systemic insecticides are incorporated directly into the plant host so that once the invasive insect attacks the host, it is exposed to the chemical. This method treats not only adult insects, but also egg and larvae stages. Chemical control has proved to be a problem in the past; DDT (dichloro-diphenyl-trichloroethane) is thought to have caused problems with birds and aquatic life unitl it was removed from the market in the 1970s.
  
  
• Biological – There have been many success stories of the use of insects and other organisms to control or eradicate invasive insects. These organisms eat invasive insects, or they lay eggs in the target insects’ larvae, which then become the attacking insects food. One particular example is red imported fire ants (Solenopsis invicta). When a nematode (Neoaplectana carpocapsae) is applied to an ant mound, a high percentage of these mounds are destroyed. Also being studied as a possible biological control of fire ants is an insect from South America, Pseudocteon curvatus. This insect actually severs the head of the fire ant from its body, a rare event in the insect world. In addition, there are instances of environmental problems caused by the introduction of biological control organisms that themselves became invasive species in their new habitat.
  
  
• Mechanical – Under certain circumstances, the nests of invasive insects can be destroyed by fire, water, or physical destruction, such a plowing an ant mound.