Kaneko Junichi, Katagiri Chihiro
National Agricultural Research Center for Hokkaido Region, Hitsujigaoka 1, Sapporo, 062-8555, Japan.
Naturwissenschaften. 2006 Aug;93(8):393-6. doi: 10.1007/s00114-006-0116-z. Epub 2006 May 3.
Differences in colour and shape have been used to discriminate diapause pupae from non-diapause pupae in butterflies. In the present study, we describe a simple discrimination method based on differences in the specific gravity of diapause and non-diapause pupae of large and small white butterflies, Pieris brassicae and Pieris rapae crucivora. When put into water, diapause pupae sink to the bottom (specific gravity is above 1.0), whereas non-diapause pupae float on the surface (specific gravity is below 1.0). Nuclear magnetic resonance microimaging revealed that this difference in specific gravity is due to a difference in the volume of an internal cavity located between the thorax and the abdomen in the pupae. The cavity appears quite early in development. We also examined the cavity in pupae of the unrelated swallowtail butterfly, Papilio xuthus, and found a similar cavity. However, in this species, the cavity is very small and, as a consequence, non-diapause as well as diapause pupae sink in water.
颜色和形状的差异已被用于区分蝴蝶的滞育蛹和非滞育蛹。在本研究中，我们描述了一种基于大型和小型白粉蝶（粉纹夜蛾和菜粉蝶）滞育蛹和非滞育蛹比重差异的简单区分方法。将蛹放入水中时，滞育蛹会沉到水底（比重高于1.0），而非滞育蛹则漂浮在水面（比重低于1.0）。核磁共振显微成像显示，这种比重差异是由于蛹胸部和腹部之间内部腔体体积的差异所致。该腔体在发育早期就出现了。我们还检查了不相关的凤蝶科蝴蝶（柑橘凤蝶）蛹中的腔体，发现了类似的腔体。然而，在这个物种中，腔体非常小，因此非滞育蛹和滞育蛹都会沉入水中。
