Crank up the war machine: Nutria have reached the Delta.Myocastor coypus, a rapidly breeding, super-destructive Argentinean swamp rat that grows as big as a medium-sized dog, was found days ago on Roberts Island.“This discovery throws us for a loop,” said Peter Tira, a spokesman for the California Department of Fish and Wildlife.That’s because the northernmost detection of this invasive, semi-aquatic, 20-pound rodent had [...]