Spatial patterns of correlated scale size and scale color in relation to color pattern elements in butterfly wings

Self-Similarity, Distortion Waves, and the Essence of Morphogenesis: A Generalized View of Color Pattern Formation in Butterfly Wings

“…Scale size distribution is graded from the basal to peripheral areas of a wing in butterflies and moths Simonsen and Kristensen 2003). Similar size gradation has been found in the background scales in Junonia orithya, J. almana, Vanessa indica, and V. cardui (Kusaba and Otaki 2009;Dhungel and Otaki 2013;Iwata and Otaki 2016b). What about the size of scales that constitute elements?…”

“…What about the size of scales that constitute elements? In J. orithya and J. almana, the scale size of an element is larger than that of its surrounding background (Kusaba and Otaki 2009;Iwata and Otaki 2016b) (Fig. 7.10).…”

“…This rule may sound trivial but is indeed important as a clue to understanding the possible nature of morphogenic signals for color patterns (see below). Furthermore, the largest scales in an element are found roughly at the center of an element (Kusaba and Otaki 2009;Iwata and Otaki 2016b). This may be called the central maxima rule for elemental scale size.…”

“…This mechanism can be explained by the ploidy hypothesis (Iwata and Otaki 2016b), which states that the morphogenic signal for color patterns is indeed a ploidy signal that induces polyploidization and cellular size increase (see below), together with the physical distortion hypothesis, which states that cellular and epithelial distortions act as morphogenic signals (see below). The origin of distortions can be considered as organizing centers.…”

“…7.10 Scale size distribution on a wing of Junonia almana. Reproduced from Iwata and Otaki (2016b). A dorsal forewing was examined along lines a, b, and c in 1.0 mm intervals (left).…”