Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary

Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

Corrigendum to: Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary

Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

Monitoring of adult aquatic insect activities and ecological role in the riparian zone of streams in the Western Ghats, India

<div><p><em>The Western Ghats, running parallel to the west coast of India between 8° N and 21° N is a prominent feature of the peninsular India. In freshwater biodiversity hotspots like the Western Ghats, no information is available on activates and ecological role of adult aquatic insect in the riparian zone of streams.</em><strong><em> </em></strong><em>Most adult aquatic insects that emerge from streams live briefly in the nearby riparian zone. Adult activities, such as mating dispersal and feeding influence their distribution in the terrestrial habitat. An observation at Kurangani streams, Western Ghats, India has shown that both numbers and biomass of adult aquatic insects are greatest in the near stream vegetation; however, adult insects can be relatively common 1 to 10 feet from the stream. Why because, adult aquatic insects are abundant and they are primary food resource for many riparian insectivores. The role of adult aquatic insects in the riparian zone must be better understood for riparian and aquatic food chain to be complete. </em></p></div>