The Stigmella maya has a wingspan of 2.5mm and is the smallest moth known to science. But how small do you need to be to be classed as a micro-moth?
Mico-moths are the smallest moths in the world and usually have a wingspan measuring less than 20mm. As they are so tiny, they are incredibly difficult to spot and scientist often have to dissect micro-moths and examine their genitalia to identify them. There are about 1850 species of micro-moth recorded in the UK and over 62000 named worldwide. There are thought to be even more in the tropics that haven’t been given names yet.
How do we categorise moths and butterflies?
Both moths and butterflies evolved from a common ancestor roughly 250 million years ago. Traditionally, they have been split into three broad groups: micro-moths, macro-moths and butterflies. Different families developed different characteristics, habits, colours and wing structures. Many species evolved in close company with the plants they relied on for food. The micro-moths evolved early (from about 250-200 million years ago). Macro-moths are larger and evolved much more recently (from about 125 million years ago). Most macro-moths are large, and this group is technically called Macroheterocera. It contains the biggest species in the world.
How big is the world’s smallest moth?
The current smallest moth in the world is the Stigmella maya, with the forewing measuring just 1.2mm and it is found only in Yucatan in Mexico. This species is part of a group called microlepidoptera - the smallest moths and butterflies in the world. Another very tiny moth, Enteucha acetosae, is found in Britain. The smallest individuals have a wingspan of about 3 millimetres and the minute larvae live inside sorrel leaves, often turning them from green to red.