The growth of agricultural and mining activities in the Amazon has impacted land-use and caused significant changes in the local environmental conditions of streams. In the face of these changes, our study aimed at assessing how environmental changes affect Odonata larval assemblages in streams in the eastern Amazon.
Larvae were reared at 21.5°C from eggs from southernmost Sweden, and fed ad libitum to emergence in four different photoperiodic treatments, intended to represent increasing levels of time stress: constant LD 16:8, corresponding to late April (or August) conditions, a shift after about two weeks from LD 16:8 to 19.5:4.5, coarsely simulating late spring, constant…
Very little is known about the biology of larval odonates from the Neotropical region, and in particular there are no data on behavioral changes during ontogeny and growth ratios, though both are crucial to understanding the dynamics of Odonata communities. Here we study growth ratio, development patterns and behavior of Rhionaeschna marchali larvae. We characterized…
Phenotypic plasticity represents an adaptive tool in organisms including odonates to cope with heterogeneous environmental conditions. However, while some odonate species can occupy various changing habitats, other species are adapted to a narrow range of environmental conditions. Commonly, behavioural modifications are applied to avoid detection and encounters with predators. But reduced behavioural activity results in…
Of the 160 species in South Africa, 29 are endemic. Threats to the local odonate fauna have increased in recent years due to the growth of agriculture and impact of invasive alien trees. Currently, 13 species are red-listed as threatened. Among the activities to ameliorate threats, is a massive programme, ‘Working for Water’, to remove…