In 1916, the japanese beetle, Polillia japonica was introduced to the US. This pest still causes millions of dollars worth of damage per year, but in this time period there was no way to control it. It ran rampant…uncontrolled. That is, until we discovered something was killing it’s grubs.
Half a decade after it’s introduction, there was a disease discovered in Japanese beetles which caused the larvae to become white in color and then die. Many attempts to culture this pest in fermentation chambers failed, until we discovered that the bacteria needed a living host to reproduce properly (we still don’t know why this is, exactly). This disease was later dubbed ‘milky spore disease’ and the difficulty in culturing it’s causal agent, Bacillus popillae was overcome and became widely avalible as a method of control.
Everything was going fine for B. popillae until, of course Bacillus thuringiensis came along, kicked sand in it’s face and stole it’s share of the market. Bacillus thuringiensis completely changed the paradigm because unlike B. popillae, there was no need for a live insect host . Even better, there were many varieties which were specific to a group of pests. Still better, it could be cultured by fermentation. Once again, this discovery goes back to sericulture. The bacterium was discovered in diseased silkworms in 1911. It was later isolated from another moth species and then cultured and in the 1920s used for control of European corn borer in Europe.
Experimentation with BT was paused due to World War II, but experienced a resurrection in the 1950s. Many new products came on the market and competition was feirce. It has been used in recent times to control pests in North American forests. Pests such as the gypsy moth and the spruce budworm have been controlled with wide success using BT. Varients of BT which attack beetles and flies have also been used for control of various types of pests.
The success of BT is due to a toxin it produces which is specific to certian groups of insects. It basically dissolves their gut. The gut of an insect is very basic (as opposed to the mamallian gut which is acidic) and needs the basic conditions to be activated. They also need a specific receptor to bind to. This means that many BT toxins actually can’t harm humans (some can) and we can use those varients to control insects. Many companies have extracted the proteins and many crops have been modified with the BT toxin gene.
But let’s get back to the history portion, shall we? There’s still a lot more to discover…like golf’s impact on nematology.
Oh, yeah…that’s right. The game of golf has actually made it’s own divot in insect pathology. Want to know how?
You’ll have to read part III.
I’m a bastard, I know 
Filed under: General Entomology, Uncategorized | Tagged: entomology, History, Organic Pest Control, Parasitology
