Biological Control
  • Home
  • Resources
  • Biological Control History
    • Biological Control of Opuntia in Australia
    • Selective Chemicals
  • Natural Enemies
    • Parasitoids >
      • Aphid Primary and Hyperparasitoids
    • Gallery of Parasitoid Insects
    • Predators >
      • Literature on Top Predators
    • Gallery of Predatory Insects
    • Pathogens >
      • Bt and GMOs
  • Biological Control Methods
  • Ecological Concepts
    • Mutualism
    • Just For Fun
The image above shows a insecticide product that contains Bacillus thuringiensis, or Bt, a naturally occurring soil-dwelling bacteria that produces proteins that react with specific receptors on the surfaces of cells in certain insect guts.  The reaction disrupts the cell creating a perforation that allows the bacteria to move into the insect's body creating an infection that will eventually kill the insect.  The whole story is far more complicated and add to that our ability to genetically engineer the bacteria's protein makes for interesting reading.  To learn more click here.
Insects get sick, just like we do, and there are many kinds of pathogens that can make them sick. 

Well, insects do get sick...but...sometimes it's not like we do.  Click on the YouTube video below to see some parasitic Nematomorpha "horsehair" worms emerge from a mantis gut once it's in contact with water.  Click here for the full story on their biology.  Nightmarish.

Picture
Picture
The other major pathogens for insects include bacteria and viruses. The image above left shows a green, healthy and a caterpillar blackened by the bacteria Bacillus thuringiensis. and viruses that literally melt certain types of insects as seen at above  right.
There are basically three types of natural enemies:  Predators, parasitoids and pathogens.  This page focuses on pathogens.
But only a very few of these pathogens have the proper biology to make them useful in the context of biological control. 
Picture
Picture
Picture
At left is a caterpillar that has been killed off by a fungal infection.  There are dozens of fungal pathogens, but the most famous are Entomophthora muscae (center left) and cordyceps (bottom left).  Entomophthora muscae starts as a spore which is the white dust surrounding the infected fly in the photo.  If it comes into contact with another healthy fly, the spore begins to grow and penetrate into the fly's body, eventually consuming its insides and then sporulating as shown.  Cordyceps is a fungus that produces a mushroom like fruiting body as seen emerging from the ant in the photo.  What is amazing about these fungi is that they also affect their host's behavior to enable the successful completion of their life cycle.  Listen to Sir David Attenborough explain...(click video)   
Powered by Create your own unique website with customizable templates.