Emergence and adult behaviour of Macromia splendens (Pictet) in Galicia, northwestern Spain (Anisoptera: Corduliidae)

Exuviae were found in sheltered places, most commonly in small cavities under the river banks. The species is able to breed in hydroelectric reservoirs that show marked changes in water level and where riverine vegetation is completely absent. At these places exuviae were found on dead trunks and big rocks, usually in a horizontal upside-down position. In the laboratory, emergence followed the typical aeshnid sequence. Adult, full coloured males showed no yellow spots on abdominal segments 5 and 6, while the spots on segments 4 and 7 were widely variable. 37 adult males of a natural population at the river Lerez were marked. Of these, 12 were resighted 1 to 14 days after marking. Males patrolled over 50-150 m of the river, usually flying straight aljout 30 cm above the water. Females were observed at the river on 21 occasions, and in 19 cases oviposited as soon as they arrived at water. However, mating was recorded only once during 52 h of observation over 18 days. Two more matings were obtained with a tethered female. Since matings at the oviposition sites seem to be rare, it is suggested that copulation is performed mainly at the feeding places. Eggs were scattered by the unaccompanied female by dipping the abdomen 3-10 times for no more than 2 min, in spots of the river as far as 1 m from each other. The importance of forested areas for conservation of this species is discussed.