Color−magnitude diagram, J versus z−J, of the VIMOS–UKIDSS search. Previously known USco members are shown with blue filled dots. The separator (two blue straight lines) used for the selection of USco member candidates goes from J = 14.5 to 19.0 mag. The 11 unresolved sources – labeled with their abridged names – that pass the zJ criterion are plotted as red symbols: the new candidate is shown with a red solid dot, while the previously known USco member recovered here, USco J155419.99−213543.1 (Lodieu et al. 2006, 2008), is depicted with a red-filled triangle. The resolved sources complying with our zJ criterion are plotted as gray crosses, and the bulk of field detections are shown with small black dots. For comparison purposes, the average sequence of field M-, L-, and T-dwarfs normalized to the mid-M members of USco (not shown) is over-plotted with a dotted line. The 5-Myr isochrone of Chabrier et al. (2000) is included with a solid line (we adopted a distance of 145 pc). Its corresponding masses (Jovian units) are indicated on the right side.