The emerald ash borer has been found in another state for the first time. This time, it’s Iowa. Although the adult bugs merely nibble on foliage, the larvae are deadly for all species of ash trees, burrowing into the bark and depriving the tree of its ability to transport nutrients. This kills the tree. This map shows known infestation sites, with the exception of the lower peninsula of Michigan, where it was first detected in the United States. That area is considered to be generally infested. To get the latest information on this invasive pest, follow @emeraldashborer on Twitter.