The covering by scales of the wings of Lepidoptera contributes to multiple functions that are critical for their survival and reproduction. In order to gain a better understanding about their distribution, we have exhaustively studied 4 specimens of Colias crocef (Geoffroy, 1785). We have quantified the sources of variability affecting scale density. The results indicate that the scale covering of butterfly wings may be remarkably heterogeneous, and that the importance of the sources of variability differs between forewings and hindwings. Thus, in forewing the greatest variability occurs between sectors, while in the hindwings it occurs between sides, with a higher density of scales on the underside, considerably higher (almost 19%) than on the upperside. It seems likely that this difference has an adaptive value, as the hindwing underside is more exposed (in resting position) to predators. These results are in contrast with the generally accepted notion that scale covering is uniform and homogeneous. Moreover, the cover scale density is independent of the size of the specimen and therefore an average density of scales can be attributed to this species. According to our measurements C. crocea has 312 scales/mm² and the total number of scales per individual is about 520,000 on average.

鳞翅目鳞片的鳞片覆盖有助于实现对其生存和繁殖至关重要的多种功能。为了更好地了解它们的分布，我们详尽地研究了4个Colias crocef标本（Geoffroy，1785年）。我们已经量化了影响尺度密度的变异性来源。结果表明，蝴蝶翅膀的鳞片覆盖范围可能非常不均一，并且在前翅和后翅之间，可变性来源的重要性也有所不同。因此，在前翅中，最大的变异发生在扇形之间，而在后翅中，变异发生在侧面之间，下侧的鳞片密度更高，比上侧的鳞片密度高得多（几乎为19％）。这种差异似乎具有适应性的价值，因为后翅的下侧更容易被掠食者暴露（处于静止位置）。这些结果与普遍接受的关于鳞片覆盖是均匀和均质的观念相反。此外，覆盖鳞片的密度与标本的大小无关，因此鳞片的平均密度可以归因于该物种。根据我们的测量cro。crocea的鳞片为312鳞片/ mm ²，平均每个个体的鳞片总数约为520,000。