Can the bleed air for deicing the wings of the aircraft be switched on and off for jumbos?
Yes. Automatic operation exists as well (may not be installed/chosen by the operator).

Nitpicking: this bleed air is for anti-ice, not de-ice (but even manufactures get it wrong in the manuals sometimes, see below).

Saving this bleed air when not needed saves fuel and engine wear, and allows higher more efficient cruise altitudes.

Speaking of the A380, due to its thick wing, it does not need much anti-icing.

(Source: A380 FCOM)