Palp sensory surface of basal Lepidoptera. A. Pointed long trichoid sensillum on the fourth segment of a maxillary palp of a Micropterix maschukella female; B. Scale on the fourth segment of a maxillary palp of a Eriocrania cicatricella male; C. Apical part of the third labial palp segment of a M. maschukella male; D. Fifth maxillary palp segment of a M. maschukella female. Abbreviations: cfs = campaniform sensilla; chs-s = short blunt chaetoid sensilla; chs-n = nail-shaped chaetoid sensilla; lts = pointed long trichoid sensilla; mps = mushroom-like pseudoplacoid sensilla; s = empty socket of pointed long trichoid sensilla; sc = scales; sf = sensory field; tbs = thick basiconic sensilla.