Ameletopsis perscitus
The Yellow Mayfly (Ameletopsis perscitus) should be celebrated as perhaps the most beautiful mayfly (piriwai) in Aotearoa | New Zealand, if not the world. Draped in vibrant yellow, the sub-imago (sexually immature adult) stands out in stunning contrast against the muted greens of its native forest surroundings.
This piriwai’s uniqueness extends beyond its striking appearance. It is the sole species in its genus and the only representative of the exclusively Gondwanan family Ameletopsidae in Aotearoa. As an adult and unable to eat, it leads a brief life — the female has only a few days, often less than a week, to mate and deposit her impressive clutch of up to 8,000 eggs back into the stream.
Yet, beneath its elegant and ephemeral beauty lies a darker, more fearsome origin. In its aquatic nymph stage, Ameletopsis perscitus is a formidable predator — a very rare trait among mayflies. With lightning speed, the nymph ambushes and devours unsuspecting aquatic insects, employing powerful jaws concealed beneath a comically oversized head.
This striking duality between the delicate, transient beauty of the adult and the predatory ferocity of the juvenile presents a fascinating paradox: a creature that is both a fleeting symbol of elegance and yet was a ruthless hunter.
Aquatic entomologists love to uncover the hidden wonders of our aquatic insect diversity, extending beyond the well-known dragonflies and damselflies. Our waterways boast an extraordinary legacy of uniqueness with a 100% endemic mayfly, stonefly, and caddisfly fauna, meaning they are found nowhere else on earth! These insects are the equivalent of canaries in our waterways, vital to the health and balance of freshwater ecosystems, and the first to disappear as water quality degrades. Each of these amazing insects has a fascinating story to tell.
Unfortunately, the increasing pressures of pollution, habitat loss, and deforestation often shift attention to more visible and charismatic species like native freshwater fish. While these concerns are valid, it’s equally crucial to highlight the plight of lesser-known yet essential insects like Ameletopsis perscitus. This nomination aims to shine a light on these overlooked gems, celebrating their beauty and raising awareness about their indispensable role in maintaining ecological health.
Truly, Ameletopsis perscitus is a worthy contender for the title of Bug of the Year 2025. Let’s champion the tiny, the vital, and the irreplaceable, and vote for yellow!
Check these links for more info on the Yellow Mayfly in NZ
Wikipedia: Information on Ameletopsis perscitus
For Media Enquiries
For media enquiries, you can contact Bug of the Year Committee or the Champion running the campaign for the Yellow Mayfly: Brian Smith / NIWA
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