Characters of immatures are potentially useful in identifying taxa, but few immatures of Pentatomidae were described. The objectives here are to describe the egg and five nymphal instars of Caonabo pseudoscylax (Bergroth) under light and scanning electron microscopy. Adults, eggs, and nymphs were collected on Homolepsis glutinosa during 2008, in Criciúma (Santa Catarina, Brazil). The egg of C. pseudoscylax is subcylindrical, chorion reddish brown, slightly translucent, and with granulate surface. Aero-micropylar processes translucent, spongy, and strongly clavate. Nymphs without punctures, spiracles placed near the lateral abdominal margin. The dorsal abdominal gland has rounded ostioles bearing cuticular valve; spout peritreme smooth, directed anteriorly; evaporatorium network-shaped; and microsculpture poorly ornamented. Humeral angles of the pronotum were produced from fourth instar. The almost marginal placement of abdominal spiracles may diagnose the nymphs of C. pseudoscylax from first instar to adulthood.

The presence of catfish of the Ariidae family in the list of endangered species of Rio Grande do Sul (RS), as from 2014, led to forbidding fishing two species of this family. Thus, artisanal fisherfolk lost a significant part of their income, causing conflicts between them and the fishing authorities in RS. This work aims mainly to understand the Local Ecological Knowledge (LEK) of the artisanal fisherfolk of the North Coast of RS regarding the ecology and taxonomy of catfish of the Ariidae family, seeking to relate it to the establishment of the fishing regulations in force in the State. 33 semi-structured interviews were made with artisanal fisherfolk. The interviewees perceive differences among the region ethnospecies; hardly ever are they consulted during the fishing regulations establishment process. Considering the aforementioned aspects, the artisanal fisherfolk LEK on catfish can be an important tool in the participatory management of catfish fishing.