“[D]on’t be afraid; you are more valuable to God than a whole flock of sparrows.”
– Matthew 10:31
According to a dominant view it is the capacity to feel pain or pleasure that confers full moral status on an organism; man and mosquito are alike in their sentience and full subjects with moral .worth. The roughly antithetical view holds that full moral status conferral is contingent on membership with the sapiens species; man is the measure of moral worth because man alone is sapient. Call the former view Capacitist and the latter Speciesist. Some capacitists about moral status conferral object that speciesists’ attributions of low and high moral worth respectively to mosquitoes and humans are arbitrary and unjustified. But, to the credit of speciesists about moral status conferral, such differentials in cross species attributions of moral worth are not arbitrary.
There are an estimated 1,000,000,000,000,000 mosquitoes and 8,000,000,000 humans alive today. If moral worth is distributed equitably among all species, a human life is morally equivalent to 125,000 mosquito lives. 1000000 people die from mosquito bites each year. Breeding 125,000,000,000 mosquitoes is a deed equivalent to saving 1000000 human lives each year. Since we tend to think killing off mosquitoes is superior to breeding them, we must think breeding mosquitoes is inequivalent to saving human lives. Ergo, mosquitoes haven’t the same moral weight as humans.
To conclude with an answer to the leading question: 125,000 mosquitoes a man.