Declana floccosa, the forest semilooper, is a moth of the family Geometridae. It is native to New Zealand. The wingspan is 27–35 mm and is extremely variable in colour and patterning. The larvae feed on a wide range of native and exotic broad-leaved and coniferous shrubs and trees. Exotic hosts include Pinus radiata and other Pinus species, Pseudotsuga menziesii, Larix and Eucalyptus.