{"id":6184,"date":"2026-10-06T07:06:32","date_gmt":"2026-10-06T07:06:32","guid":{"rendered":"https:\/\/life2rivers.si\/ziva-reka-6-epizoda-vrbnice-in-enodnevnice-recni-bioindikatorji\/"},"modified":"2026-10-06T07:25:17","modified_gmt":"2026-10-06T07:25:17","slug":"alive-river-6-stineflies-and-mayflies","status":"publish","type":"post","link":"https:\/\/life2rivers.si\/en\/alive-river-6-stineflies-and-mayflies\/","title":{"rendered":"ALIVE RIVER, Episode 6: Stoneflies and Mayflies, the River\u2019s Bioindicators"},"content":{"rendered":"

In the sixth episode, we explore stoneflies<\/strong> (Plecoptera<\/em>) and mayflies<\/strong> (Ephemeroptera<\/em>). Although adults can be seen near rivers, they spend most of their lives as aquatic larvae.<\/p>\n

How do we tell them apart?<\/strong><\/p>\n

Stonefly larvae have two long tail filaments, while mayfly larvae usually have three. Mayfly larvae also have clearly visible gills along the abdomen, whereas stoneflies have theirs on the thorax or near the legs. Adult stoneflies have two pairs of wings that lie flat against the body when at rest, while mayflies hold their characteristic triangular wings upright.<\/p>\n

\"Odrasli

Adult stoneflies from the family Perlidae. Photo: Annasibila Po\u017erl <\/span><\/p><\/div>\n

They spend most of their lives underwater<\/strong><\/p>\n

Stonefly larvae live mainly on the bottom of clean, well\u2011oxygenated rivers and streams. Some feed on algae and decaying plant material, while others are predators of smaller aquatic animals. Their larval development can last from one to four years, during which they may molt 12 to 36 times. Eventually, they crawl out of the water and molt one last time into adults. Adult stoneflies usually live only a few weeks and rarely move far from the water.<\/p>\n

Mayflies also spend the vast majority of their lives underwater. Their aquatic phase can last several months, often around a year, and in some species even two years or more. In contrast, their adult life is extremely short \u2014 from a few hours to a few days \u2014 and is devoted almost entirely to mating and laying eggs.<\/p>\n

The name \u201cmayfly\u201d is therefore a bit misleading: the insect may live for a year or more, but almost all of that time is spent hidden under stones in flowing or still waters. Only at the very end of its life does it develop wings and fly onto land.<\/p>\n

What do they tell us about the river?<\/strong><\/p>\n

Stoneflies and mayflies are important bioindicators of ecological water quality. Stoneflies in particular require cold, oxygen\u2011rich water and are sensitive to pollution. Finding a diverse community of these sensitive species on the riverbed is a good sign that the river provides a high\u2011quality habitat.<\/p>\n

They are also an essential part of the river\u2019s food web: by feeding, they help regulate the growth of smaller organisms, and they serve as food for larger animals such as fish and birds.<\/p>\n

Did you know?<\/strong><\/p>\n

At the end of summer, you can witness mayfly swarming, when an entire local population transforms into adults at once. Their mating dance fills the air, and after mating and laying eggs, they die \u2014 adult mayflies have reduced mouthparts and cannot feed.<\/p>\n

A healthy river is not just clean water. It is a living ecosystem \u2014 even under the stones, where a hidden world thrives, often unnoticed at first glance.<\/p>\n

 <\/p>\n

References: <\/span>https:\/\/en.wikipedia.org\/wiki\/Mayfly<\/span><\/a>; <\/span>https:\/\/en.wikipedia.org\/wiki\/Plecoptera<\/span><\/a>; <\/span>https:\/\/www.inaturalist.org\/observations\/182666898<\/span><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

In the sixth episode, we explore stoneflies (Plecoptera) and mayflies (Ephemeroptera). Although adults can be seen near rivers, they spend most of their lives as aquatic larvae. How do we tell them apart? Stonefly larvae have two long tail filaments, while mayfly larvae usually have three. Mayfly larvae also have clearly visible gills along the […]<\/p>\n","protected":false},"author":4,"featured_media":6159,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[27],"tags":[71],"class_list":["post-6184","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-novice-en","tag-alive-river"],"acf":[],"_links":{"self":[{"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/posts\/6184","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/comments?post=6184"}],"version-history":[{"count":6,"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/posts\/6184\/revisions"}],"predecessor-version":[{"id":6191,"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/posts\/6184\/revisions\/6191"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/media\/6159"}],"wp:attachment":[{"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/media?parent=6184"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/categories?post=6184"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/life2rivers.si\/en\/wp-json\/wp\/v2\/tags?post=6184"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}