Fig. 6

Size distribution in each colony of a P. angustipennis spadica (colony size ≥ 5) and b S. esakii (colony size ≥ 10). Different numerals indicate different colonies: Nos. 1 and 2 in a and Nos. 1−22 in b. The collection date is shown in the upper right, and categories of colony (AP: An adult pair and nymphs; MA: A male adult and nymphs; FA: A female adult and nymphs; ON: Only nymphs) are shown under the collection date. In b Nos. 4 and 15, pronotum width was not measured for one individual in each colony, and two were not measured in b No. 11. Each histogram cell contains individuals separated by 0.5 mm in pronotum width. In b S. esakii, Nos. 1−15 contained single group of nymphs of similar sizes (max / min ratio in nymphal pronotum width < 1.7), and Nos. 16−22 contained multiple groups of nymphs.