We've always known that trapping causes an increase in breeding and immigration by other coyotes. The only real way to really kill them off would be to do so with a virus. A few year back a mysterious virus killed some domestic dogs in boarding kennels in Ohio and a couple other states. Canine circovirus. Not much is known about it other than its super deadly and usually kills in a few days with internal bleeding. It is also highly contagious. A well planned catch, infect, and release program would absolutely devastate them since they're a social pack animal that travel large distances. Point being, if a state wanted them dead there are options.
Years ago the screw fly was eradicated in the southern US by cultivating Flys then steralizing them with radiation and releasing them in the wild. The fertile wild insects spent precious breeding time screwing around with infertile partners. This reduce the propagation success rate year after year until they went extinct.
