Diversity and Ecosystem Services of Trichoptera

Abstract

The holometabolous insect order Trichoptera (caddisflies) includes more known species than all of the other primarily aquatic orders of insects combined. They are distributed unevenly; with the greatest number and density occurring in the Oriental Biogeographic Region and the smallest in the East Palearctic. Ecosystem services provided by Trichoptera are also very diverse and include their essential roles in food webs, in biological monitoring of water quality, as food for fish and other predators (many of which are of human concern), and as engineers that stabilize gravel bed sediment. They are especially important in capturing and using a wide variety of nutrients in many forms, transforming them for use by other organisms in freshwaters and surrounding riparian areas. The general pattern of evolution for trichopteran families is becoming clearer as more genes from more taxa are sequenced and as morphological characters are becoming understood in greater detail. This increasingly credible phylogeny provides a foundation for interpreting and hypothesizing the functional traits of this diverse order of freshwater organisms and for understanding the richness of the ecological services corresponding with those traits. Our research also is gaining insight into the timing of evolutionary diversification in the order. Correlations for the use of angiosperm plant material as food and case construction material by the earliest ancestors of infraorder Plenitentoria—by at least 175 Ma—may provide insight into the timing of the origin of angiosperms.

A novel leaf-rolling chironomid, Eukiefferiella endobryonia sp. nov. (Diptera, Chironomidae, Orthocladiinae), highlights the diversity of underwater chironomid tube structures

“…The tube morphology of chironomids does indeed show significant diversity. It is likely that lability in silk production, particle and substrate selection, and construction behavior has made it possible for chironomids to use a broad array of ecological niches, as is the case for the Trichoptera (Weaver and Morse 1986;Wiggins and Mackay 1978;Mackay and Wiggins 1979;Wiggins 2005;Morse et al 2019). Future investigations of the evolution and diversification of construction behaviors in chironomids in relation to changes in available habitat types will be important to improve our understanding of the evolution of aquatic ecosystems.…”

Taxonomic Catalog of the Brazilian Fauna: order Trichoptera (Insecta), diversity and distribution

“…The caddisflies, order Trichoptera, represent a diverse lineage of aquatic insects, currently with more than 16,000 named species (Morse et al 2019). They are sister group to the megadiverse order Lepidoptera, and together they constitute the well-defined superorder Amphiesmenoptera (Kristensen 1997, Misof et al 2014.…”

Shifts in the community composition of caddisflies (Insecta: Trichoptera) in a subtropical river over three decades

“…Trichoptera is the most speciose of the fully aquatic insect orders and is only surpassed by Diptera and Coleoptera in the number of described aquatic species (Malm et al ., ; Morse et al ., ). The order is also ecologically diverse (Mackay & Wiggins, ), comprising representatives of virtually all types of aquatic macroinvertebrate functional feeding groups, therefore fulfilling many types of functional roles within freshwater ecosystems (Wiggins & Currie, ).…”

“…A comparison of historical and contemporary caddisfly species by Houghton and Holzenthal () in Minnesota, U.S.A., showed that agricultural disturbance was associated with species loss and functional homogenisation of communities. Overall, however, the amount of research concerning Trichoptera biodiversity is disproportionately low given the high number of caddisfly species and the increasing level of threat from habitat impairment (Morse et al ., ; Sánchez‐Bayo & Wyckhuys, ). For instance, the International Union for Conservation of Nature's Red List of Threatened Species includes 449 dragonfly and damselfly (Insecta: Odonata) species, but only five Trichoptera species (IUCN, ).…”