Scale length/wing length correlation in Lepidoptera (Insecta)

Significant positive correlation between wing length and scale length was found in a broad sample of lepidopteran taxa. No breakdown of the correlation was observed in the lowest wing size range. The best fit is a non-linear (power) curve. The minimum individual scale length observed was 40 mum (in a nepticulid), while the maximum was close to 500 mum (in a castniid; there are literature records of even larger scales in this family). Scale size variation probably reflects variation in the size of scale-forming trichogen cells. The latter, in turn, may at least partly reflect difference in genome size, such as has long been known to be the case with the cells that form, respectively, the cover and ground scales in some higher moths.