Changing distribution patterns along a stream in adults of Calopteryx haemorrhoidalis (Odonata: Calopterygidae): a case of larval-drift compensation?

The distribution of an isolated population of adult Calopteryx haemorrhoidalis was studied along a small stream in NE Spain, during two-week or three-week summer periods over five years. Distribution patterns differed consistently between age groups. Reproductive activities took place along the entire stream, whereas the presence of tenerals and older immature individuals was restricted to…

Voltinism of Calopteryx haemorrhoidalis, (Vander Linden) in the Sierra Morena Mountains, Southern Spain (Zygoptera: Calopterygidae): A preliminary study

Small sweep-net samples of larvae of Calopteryx haemorrhoidalis, obtained during five consecutive years from a permanent stream in the Sierra Morena Mountains, southern Spain, were combined according to month to infer the voltinism during the study period. Detailed records of head width, wing-sheath length and metamorphosis status for individual larvae are consistent with the population…

To stay or not to stay: Decision-making during territorial behaviour of Calopteryx haemorrhoidalis and Calopteryx splendens splendens (Zygoptera: Calopterygidae)

The effect of copulation and presence of predators on territorial behaviour of male Calopteryx haemorrhoidalis (in southern France) and of male C. splendens splendens (in northern Germany) was studied in nature. A male obtaining a copulation early in the day often secured more copulations later that day than did males not obtaining an early copulation….

Hybridization between Calopteryx splendens and C. haemorrhoidalis confirmed by morphological and genetic analyses

Hybridization between Calopteryx haemorrhoidalis and any of its congeners has not been reported until now. We observed spontaneous matings between male C. splendens and female C. haemorrhoidalis at a locality in Central Italy, together with some putative hybrid individuals that had a mixed phenotype. Here, we report the morphological and molecular characterization of five suspected…

Repeated predation of Odonata by the hornet Vespa crabro (Hymenoptera: Vespidae)

Predation of aggregated, ovipositing tandems of Sympetrum sanguineum and S. vulgatum by the hornet Vespa crabro was observed in Belarus. The same species of hornet was seen killing territorial males and copulating females of Calopteryx haemorrhoidalis in Italy. Numerous remains of these odonates at the oviposition sites suggest that attacks occur frequently. A short review…