Pistachio seed chalcid

Megastigmus is a genus of minute wasps. The Pistachio seed chalcid, Megastigmus pistaciae, is a pest of pistachios in North Africa and Mediterranean and Middle East countries. It was first discovered in North America in Chico, California, in 1967. Its distribution now includes major portions of the Sacramento and San Joaquin Valleys and limited areas of southern California.