Unguizetes ermilovi sp. nov. from Malaysia and its morphological ontogeny is described and illustrated and compared with congeners. The adult of U. ermilovi sp. nov. has well developed lamellae and translamella, being the most similar to U. clavatus Aoki, 1967 and U. inermis Mahunka, 1990, but differs from them by the shape of the lamellar complex and porose areas on the notogaster. Most prodorsal and gastronotal setae of juveniles of the new species are long. The larva has 12 pairs of gastronotal setae, of which c₂, la and lp are of medium size and h₃ is short, and c₂, l-series and h₁ are with excentrosclerites. The nymphs have 15 pairs of setae, of which c₂, la and p-series are short, and all gastronotal setae are with excentrosclerites.