Mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera) — EPT for short — are often found in similar habitats as both larvae and adults. They rely on good quality habitats directly in the water as well as in the terrestrial surroundings to complete their life cycles and sustain healthy populations. The health of a waterbody is dependent on many factors, the primary ones being water and habitat quality. These three insect orders are often commonly used in water quality monitoring and assessment. As their habitat requirements span all kinds of freshwater habitats from ditches to lakes and flowing rivers, they serve as valuable bioindicators.
Many experts and researchers work on all three or two (mostly Ephemeroptera and Plecoptera) orders and the issues affecting EPT are common to all three orders. Their importance in the diet of game fish means that fly-fishers are keenly interested in these groups and this enthusiasm and interest can be harnessed to further promote their conservation. EPT provide important ecosystem services that include nutrient cycling, and the prevention of algae and detritus build-up in water bodies by grazing. Despite the importance for biomonitoring, as prey items for fish and birds, and their cultural significance, over 20,000 species of EPT have been overlooked when considering the conservation of freshwater invertebrates.
The Mayfly, Stonefly and Caddisfly Specialist Group was established to promote the conservation of EPT species and their habitats around the world.
The group raises awareness of these small but important orders and undertakes red list assessments to inform practical conservation activities.