Oviposition site preference and egg parasitism in Sympecma paedisca (Odonata: Lestidae)

Abstract

Oviposition of Sympecma paedisca was observed in eastern Kazakstan. The main oviposition substrates were living Phragmites leaves. In comparison with European and Japanese populations we propose geographic variation in the proportional use of horizontal versus vertical oviposition substrates. Ovipositing females seemed to avoid the inner parts of Phragmites stands and there was a preference for individual plants. Eggs were on average 1.28 mm long and densities of up to one egg per mm² leaf area were observed. Parasitoid wasps of the genus Anagrus emerged from almost 2% of 13,938 eggs examined. Further estimates revealed that 22.4% of the eggs were parasitized. There was no significant correlation between the degree of parasitism and egg density. We propose that clutch size may not be the best female fitness parameter in endophytically laying odonate species.

Keywords: Odonata, dragonfly, Anagrus, egg parasitism, endophytic oviposition, Kazakstan, Mymaridae, parasitoid, reproductive success

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