I work in microbiology and biochemistry research. A student in my lab (her name is Anna) is investigating how Bacillus bacteria can be used to fight off the fungi that cause serious diseases in plants. This concept of biocontrol (using biological control agents instead of chemical pesticides) is a bit of a hot topic in research right now, and an industry selling biocontrol products is beginning to bloom. This can make it feel like a new idea, an innovative form of subtle environmental engineering, to use bacteria to control insect and fungal pests.

A recent re-reading of Rachel Carson’s book Silent Spring, reminds me that the idea of biocontrol is far from new.

Carson's book is credited as having kick-started the environmentalist movement, as it laid out in painstaking detail the damage we were doing to our environment by our over-use of pesticides (especially insecticides). Carson could see the incredible scale of loss inflicted on our ecosystems, the reduction in what we now call biodiversity, and she lamented the “campaign for mass chemical control…another symptom of our exaggeratedly technological and quantitative approach”.

At the very end of Silent Spring, Carson wonders if there is another way to treat the insect pests that plague our farms. She describes how Bacillus bacteria were used to kill off insect pests as early as the 1910s and 1930s! Support for these “natural” approaches to pest control waned after chemicals like DDT were discovered, as new technological solutions were thought to be inherently better than any nature-based interventions.

Now I hope that we are returning to a more ecological view of pest control; maintaining a robust and diverse ecosystem to keep pests and pathogens in check, this time armed with deep scientific knowledge about how biocontrol works. After all, as Carson said:

“For the microbes include not only disease organisms but those that destroy waste matter, make soils fertile, and enter into countless biological processes like fermentation and nitrification. Why should they not also aid us in the control of insects?”

Silent Spring and the rest of Rachel's writings on the environment are available from all good bookshops, online or otherwise.