Cuticular sensilla on newly hatched larvae of Cuterebra fontinella Clark (Diptera : Cuterebridae), Hypoderma lineatum (de Vill.) and H. bovis (L.) (Diptera : Oestridae) were studied by scanning electron microscopy. Three basic types of sensilla were found on C. fontinella larvae, while only 2 were present on the larvae of Hypoderma spp. Sensilla were more numerous on the C. fontinella larvae than on the Hypoderma spp. larvae (210 vs 66). There were no noticeable differences between the sensory complements of H. lineatum and H. bovis. Comparison of the number and type of sensilla on the parasitic larvae with those on free-living muscomorph Diptera larvae indicate that increasing numbers and greater morphological diversity correlate with increasing requirements for location of a suitable environment in which to feed and develop.