Defect chaos is studied numerically in coupled Ginzburg–Landau equations for parametrically driven waves. The motion of the defects is traced in detail yielding their lifetimes, annihilation partners, and distances traveled. In a regime in which in the one-dimensional case the chaotic dynamics is due to double phase slips, the two-dimensional system exhibits a strongly ordered stripe pattern. When the parity-breaking instability to traveling waves is approached this order vanishes and the correlation function decays rapidly. In the ordered regime the defects have a typical lifetime, whereas in the disordered regime the lifetime distribution is exponential. The probability of large defect loops is substantially larger in the disordered regime.
