Followup to CNM Tetramesa postings from SteveBorkowsis and Eland. Checked mainly Tall form of alg at this location esp. old dry culms. Stripped leaf sheaths from the culms and many exit holes found - see images 3&4. I harvested ca. 20 stems, just the lower parts from 2nd-4th nodes. Wasps to 3mm seen chewing (attempting to emerge from stems?) so contained the collection. 70-80 wasps emerged in 6 days. All released. 5th image is split culm showing black, near-mature insects, apparently trapped and dead.