EPOW - Ecology Picture of the Week

The Function and Fate of Mayflies

Mayfly (unidentified species), Order Ephemeroptera
Hamurana Springs Nature Reserve, Rotorua, North Island, New Zealand

Explanation:  Mayflies!  They are harmless (don't bite, don't sting) ephemeral creatures of streams, rivers, pools, and lakes.  Adults lack mouth parts, so not only can't they bite, they can't eat.  They live for a matter of hours or days, with the sole purpose to procreate and prolong the population.  

This week we are exploring Hamurana Springs Nature Reserve near Rotorua, on North Island, New Zealand.  We'll take a look at some of the amazing features of this reserve in future EPOW episodes.

But our focus this week is on this spindly insect.  I discovered this individual clinging to the bark of a tree along the streambank.  

Mayflies are important prey for fish and other vertebrates in the aquatic and riparian ecosystem.  They contribute importantly to the trophic health of the environment, even if they do occur in intermittently-emerging swarms.  

New Zealand has some 55 species of mayflies among 20 genera in 8 families (Pohe 2018), and all of the species and genera, and 3 of the families, are endemic to New Zealand, not found anywhere else in the world!

However, many populations and species of mayfly, as with other aquatic invertebrates, are threatened by human activities -- pollutants and toxins in the water, diversions and drawdowns reducing or eliminating water quantity, and other threats.

Mayflies can play key roles as bioindicators of human disturbances and habitat quality.  So it is in our own best interest to see that they persist in healthy states. 

Information:
    Peters, W. L. 2001. The Ephemeroptera of New Zealand and New Caledonia.  Pp. 43-45 in: E. Dominguez, editor. Trends in Research in Ephemeroptera and Plecoptera. Kluwer Academic / Plenum Publishers.
    Pohe, S. R. 2018. An annotated checklist of New Zealand mayflies (Ephemeroptera), 2018. New Zealand Natural Sciences 43:1-20.