Ventilation behaviour of Orthetrum cancellatum larvae: influence of the current temperature and rearing conditions (Odonata: Libellulidae) — The intensity of respiration of larval Anisoptera can be determined by observing the frequency of abdominal movements. We used this to study the influence of the current temperature on the larval respiration of O. cancellatum. We assumed that (1) the breathing rate of the larvae increases with rising temperature and that (2) the response to the current temperature depends on the rearing conditions. The larvae were kept for nine months under four different rearing conditions. The egg clutches originated from two countries in different climate zones, from southern France in the Mediterranean area and from northern Germany in the temperate zone. Our experiment revealed that the ventilation rate increased with increasing temperature. This was more pronounced with higher rearing temperatures that the larvae experienced. We interpreted this as a habituation effect. The size of the larvae influenced the ventilation rate as well. On the other hand, the genetic and geographic origin of the larvae had no significant effect.