While studying the colonization of newly setup ponds by dragonflies, I was able to gather additional data on the minimum time period of the larval stage of L. quadrimaculata under natural conditions. At the end of September 1981, a new pond was created in an unused meadow north of Rieseberg, 15 km E of Brunswick, Fed. Rep. Germany (52° I8'I5"N, I0°47'I0"E), and was left to natural succession. The pond is situated on the north side of a forest, in the depression of a brook. In 1982, the emergent vegetation was represented by Glyceria fluitans only, growing all over the water surface. Since 1983, vegetation has developed around the shores of the pond consisting of Juncus articulatus, J. effusus and Ranunculus flammula.