Idaea poecilocrossa is a moth of the family Geometridae. It is found in northern Madagascar and on the Seychelles.[1]
This species has a wingspan of 9-13mm. The forewings are narrow with a very long cell; whitish; easily recognizable by its thick sinuous postmedian line placed close to termen and its violet-grey subterminal shading, brown costal edge and fringe. The cell dot is black, median line nearly straight. The hindwings are distally similar to the forewings.[2]