A preliminary study on female-limited colour polymorphism in Lestes sponsa

Female-limited colour polymorphisms are widespread in Odonata, usually showing an androchrome and one or more gynochromes. Androchromes have been hypothesized to function as male mimics with a consequent decrease of male harassment, although males may also learn to recognize the different female colour morphs. In the Eurasian damselfly Lestes sponsa, the occurrence of two female…

Using distance sampling to quantify Odonata density in tropical rainforests

Quantitative data are essential for many aspects of ecological research. Several methods exist to quantify odonate abundance, but complications may arise when abundances in different habitats need to be compared. In this study, I explored a technique that can overcome the variable detectability of odonates in habitats with different visibility. Distance sampling is briefly introduced…

Critical species of Odonata in Madagascar

Madagascar has approximately 175 species of Odonata. Of the Anisoptera ca 60% is endemic and of the Zygoptera almost 95%. The endemic species can roughly be separated into ‘new endemics’ that are probably recent arrivals from the African mainland and ‘old endemics’. The latter group includes many members of the families Megapodagrionidae, Platycnemididae and Corduliidae,…