Logarithm of C₂H (N = 3– 2, J = 7∕2–5∕2, F = 4–3 and F = 3–2) integrated line luminosity of the new Lupus observations presented in this paper in black (left panel) and of the discs presented by Bergner et al. (2019) in red (right panel). Empty triangles show the C₂H non-detections as 3-σ upper limits.The dotted lines show the median integrated C₂H line luminosity of the detected Lupus discs, in black, and of the detected additional sources, in red. We note the much larger dynamic range of our ALMA data.