Natural history of C. pampeanus on S. weinmannifolius. A host plant patch at the type locality; B young developing galls within swollen stems (asterisks); C dissected swollen stem showing developing gall inside (indicated by arrow); D transversally sectioned young gall showing second instar larva inside; E group of external developing galls on branch; F transversally sectioned, full grown gall, showing last instar larva inside; G young dehiscent gall; H detail of emergence orifice left by adult on distal portion of old, empty gall (pointed by arrow in J); I detail of young dehiscent gall (arrow in G), showing orifice clogged by larval feces (asterisk); J old, empty, overwintered gall. Scale bars: 2 mm (B); 1 mm (C, F, G, H, I, J); 0.5 mm (D); 5 mm (E).