Cellulase activity in diplogastrid nematodes. The cellulase activity assays were performed on carboxymethylcellulose agar plates [3, 23]. Clear halos were detected in the supernatants of P. uniformis, P. entomophagus, P. aerivorus, P. pseudaerivorus, P. sp. 11, P. sp. 15, and K. sudhausi mixed-stage cultures and in the positive control (Aspergillus). No halos were observed in the supernatants of mixed-stage cultures of Acrostichus sp. and D. magnus and the negative control (Escherichia coli).