A large, fast-breeding rodent that tears through wetlands and crops has raised alarm among Solano County officials and farmers. Nutria, which may grow up to 2 feet long and weigh 20 pounds, were discovered in the Central Valley as early as 2017, after going undetected for 40 years in California. But recently they’ve multiplied. State Fish and Wildlife efforts have captured a total of 5,171 nutria across 10 counties, including Stanislaus, Fresno, San Joaquin, Mariposa, Sacramento, Contra Costa, Madera, Tuolumne and Solano.  The fear is they will migrate to other North Bay areas beyond the Suisun Marsh, specifically into sensitive wetlands and watersheds, such as the Napa-Sonoma Marshes Wildlife Areas, San Pablo National Wildlife Refuge and San Francisco Bay.