Figure 1: Substrate tests of stick insect gut extracts.

The positive control was the gut extract of the beetle Phaedon cochleariae (Chrysomelidae, Coleoptera). Blackberry leaves were used to control for background enzymes in the diet, although guts were purged of contents before use in this assay. Aa = Aretaon asperrimus. BB = Blackberry leaves. Et = Extatosoma tiaratum. Me = Medauroidea extradentata. PGA = Polygalacturonic acid. Ps = Peruphasma schultei. Ra = Ramulus artemis. Ss = Sipyloidea sipylus.