THE LIFE HISTORY OF LESTES CONGENER (ODONATA: ZYGOPTERA) ON THE CANADIAN PRAIRIES

Abstract
Lestes congener Hagen overwinters in the egg stage. There is a diapause just before blastokinesis, during which the egg is extremely resistant to low temperatures and desiccation. Post-diapause embryonic development can occur near 0 °C but will not take place until the eggs are wetted as the pond habitat fills in the spring. Hatching does not occur until the temperature exceeds about 5 °C and is highly synchronous. Larval development is rapid and is completed in the field in about 50 days. Emergence of the adults also is synchronous. Sexual maturation requires 3 weeks. Oviposition occurs immediately after copulation while the pair are still in tandem. It takes place only in dry stems of Scirpus. Adaptations of L. congener for life under rigorous prairie conditions are discussed.
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