At the risk of being called an environmental blasphemer, I’d like to propose something shocking: the extinction of a species, entirely due to human activity may not always be a bad thing. In fact, it may be a very good thing. We have come to be taught that all species deserve to exist (not sure where the “deserve” comes from) and as such, any species that reaches the point of being critically low in number may qualify for the designation endangered species, providing it with protection under both national laws and international conventions.
In many, perhaps most cases, this protection is well warranted. Many species are enjoyed by humans for their unique properties or their place in nature. Others are vital to the balance of ecosystems or play a vital role in nature. Still others may provide vast amounts of data to science on matters of evolution, biology or even practical data, applicable to medical treatment or biological control of pests. It would be unwise to slate any species for intentional extermination without first considering whether it might have such importance and perhaps preserving some specimens, yet this does not preclude the possibility that extinction may be the best thing for humanity and nature, at least with a few species.
Numerous species of plant, animal, fungus and microbe are, dare I say it: useless and better off wiped off the face of the planet. Pathogens rank high here as do some parasites, such as intestinal worms, which are not prey or food for any species and play little role in the ecosystem, other than occasionally causing extreme pain, disease and death, often to humans. Disease vectors, such as some breeds of mosquito also may be best off being dispensed of, if it is possible to do so.
If this makes me sound a bit human-centric, I have no apologies. I happen to be a human and I also like my species quite a lot. I have no problem dispensing with little nasties that cause my fellow main to suffer or die.
So to the Rocky Mountain Locust and the Small Pox virus I say only this: Good riddance!