No, I’m most certain not saying that I personally recall plagues of Rocky Mountain locust or that Rocky Mountain locusts should be remembered fondly. In the 19th century, the Rocky Mountain locust was a major agricultural pest, with vast swarms inflicting tremendous damage to farms on the Great Plains in the 1870s in particular. And then, suddenly, the locust was no more, with the last known observation being in 1902, leaving North America as one of only two continents — the other is Antarctica — that is entirely free of locusts (i.e. grasshoppers gone bad). While doing some other research, I came across a fascinating article on the Rocky Mountain locust which includes the latest research on its disappearance in the Bozeman Magpie. A highlight:
Over the past century, this disappearance has baffled entomologists and ecologists. The collapse came, after all, before the advent of synthetic insecticides, such as DDT, or even modern farming techniques. Consequently, the leading theory for the crash seems vaguely unsatisfactory to many in the broader community of insect study. That theory holds the species was wiped out by a series of developments that played out between 1875 and 1900 in the valleys of the upper river basins along the Northern Rockies—the natural home range of the locusts between irruptions out onto the prairies.