Complex sentence: The presence of exclusively leucopterin in female wings explains the lack of iridescence in female common brimstones, since leucopterin absorbs only in the ultraviolet range, so the wings do not reflect and consequently scatter any ultraviolet like like male wings do.
Split into simpler sentences: The presence of exclusively leucopterin in female wings explains the lack of iridescence in female common brimstones, since leucopterin absorbs only in the ultraviolet range. Therefore, the wings do not reflect and consequently scatter any ultraviolet like like male wings do.