Territorial behaviour of larvae enhances mating success of male dragonflies

Laboratory experiments showed that the predatory aquatic larvae of the dragonfly, Pyrrhosoma nymphula, are territorial, defending feeding sites against intruders, and also that body length in the final instar is positively correlated with the provision of food during the last three or four larval instars. Larval length is positively correlated with larval head width which is likewise correlated with both the weight and head width of 1-day-old adults. Field observations demonstrated that larger male adults win more territorial disputes and obtain more matings near water. So the success of larvae in defending territories enhances short-term mating success in adult males.