The news that broke today about research in China that shows that some strains of bacteria have developed resistance to the Antibiotic Colistin is really worrying. Colistin has been regarded as the antibiotic of last resort so discovering mutations that are resistant could lead to the end of antibiotics as a means of treatment.
This resistance is also a very good illustration of evolution at work. If you take a population of several Billion bacteria and treat them with an antibiotic you will kill most of them, but if a few survive as they are resistant to it they will multiply producing more resistant microbes. It like the Demestos advert that states 'we kill 99.9% of all germs dead' well it's that 0.1% you need to worry about!
So how does this relate to pesticides? Well the same thing happens, farmers and horticulturists are using masses of specific pesticides and herbicides and 'resistant' crops. It just take a few resistant insects or plant strains to breed, which is far more likely if the bulk of the population has been wiped out and you get a resistant strain. This has already been seen with glyphosate resistant Black grass Alopecurus myosuroides and some insects that are become pesticide tolerant.
I think the answer is that we need to use these drugs or treatments sparingly and carefully. If we do not we could face untreatably epidemics or food shortages.
For further information on the Antibiotic resistance see: