stˈʌdiz hæv sədʒˈɛstᵻd ðæt fˈɛɹəmˌoʊnz mˈeɪ biː mˈoːɹ ɪmpˈoːɹtənt ɪn mˈiːdɪˌeɪɾɪŋ fˈiːmeɪl tʃˈɔɪs wɪðˌɪn ɐ spˈiːsiːz, wˌaɪl ˌʊltɹɐvˈaɪəlɪt ɹᵻflˈɛktəns mˈeɪ biː mˈoːɹ ɪmpˈoːɹtənt ɪn mˈiːdɪˌeɪɾɪŋ fˈiːmeɪl tʃˈɔɪs bᵻtwˌiːn spˈiːsiːz, sˈʌtʃ ɐz bᵻtwˌiːn ðə vˈɛɹi sˈɪmɪlɚ bˈʌɾɚflˌaɪz sˈiː. jˈuːɹɪθˌiːm ænd sˈiː. fˈɪlɑːdɪs.
Studies have suggested that pheromones may be more important in mediating female choice within a species, while ultraviolet reflectance may be more important in mediating female choice between species, such as between the very similar  butterflies C. eurytheme and C. philodice.