Fauna
Insect

Giant Mayfly

Hexagenia limbata

Also known as Burrowing Mayfly

The Giant Mayfly spends most of its life as a burrowing aquatic nymph in soft lake and river sediments. Huge synchronized emergences produce pale, delicate adults with upright wings and long tail filaments that live only long enough to reproduce.

Aquatic NymphMass EmergenceShort-lived Adult
Giant Mayfly reference1 / 7
(c) xpda, some rights reserved (CC BY-SA) · cc-by-sa
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyAlgae, Detrital particles, Microorganisms
Predators
  • Freshwater fish
  • Swallows
  • Dragonflies
ThreatsLow dissolved oxygen, nutrient pollution, contaminated sediment, dredging, and altered flows
HabitatsLarge lakes and slow rivers with oxygenated water and soft silt or clay bottoms
Life spanAbout 1 to 2 years as a nymph; adults live roughly one or two days
Classification
  1. OrderEphemeroptera
  2. FamilyEphemeridae
  3. GenusHexagenia
  4. SpeciesHexagenia limbata
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Emergence swarms are harmless but can make roads and walkways slippery.
Responsible observation
  • Adult: Look for upright triangular wings and two long tail filaments.
  • Habitat: Treat large emergences as signs of nearby productive fresh water.
Related species

Related species have not been added yet.

Help improve the field guideSomething wrong?

Report a name, category, or profile issue for review.

Checking your Fauna account…