Nymphs of many species of the order Odonata are easy to maintain in the laboratory, and there are hundreds of published studies dealing with behaviour, ecology, development, taxonomy, etc. that involve maintenance of nymphs under laboratory conditions. Most of these studies call for nymphs to be fed live prey, and in some cases it is possible to collect suitable prey from the field. However, in cases in which the experimental designs call for controlled diets, or in cases in which natural food is difficult to collect, as during winter months in temperate latitudes, it is common for researchers to feed nymphs with prey cultured in the laboratory. Researchers have used a variety of different prey but Daphnia sp. is one of the most popular. We have used Daphnia sp. cultures but have encountered difficulties in rearing sufficient numbers for use in experiments involving hundreds of nymphs; also, we have had the unfortunate experience of having our cultures collapse for unknown reasons at critical times of experiments.