Most Ancient Among Moths

Micropteryx calthella

The genus Micropteryx belongs to the family of moths Micropterigidae and is one of Irelands oldest Lepidopterans. They have a fossil record from the early Cretaceous (125 million years ago), where individuals recognisable as modern genera are preserved in Lebanese amber (Whalley, 1977 Nature 266 pp. 526). Micropterigidae are scattered world wide, with a concentration of species in the South-West Pacific, and more than half of Micropteryx sepcies found in the Paleartic region (Gibbs, 1983 Geo Journal 7, pp. 505–510).

They are small (c. 5 mm), colourful individuals with metallic sheens of bronze or purple and yellow forewings and are morphologically quite similar to the Lepidopteran sister group the caddisflies (Trichoptera). They are active during the day when they feed on pollen of plants with simple flowers (Schwartz-Tzachor et al., 2006 Flora 201 pp. 370–373), primitive angiosperms (e.g. Zygogynum Baillonii) sedges and fern spores (Thien et al., 1985 Science 227 pp. 540–543). Their ability to feed on pollen is due to their retention of functional mandibles (Powell, 2009, Encyclopedia of Insects (Second Edition) pp. 559-587). Other Lepidopterans either use a probiscus to feed on nectar or lack functional mouth parts and do not feed as adults.

There are four species of Micropterigidae (Ferriss et al. (ed.), 2009 Irish Biodiversity: a Taxonomic Inventory of Fauna), all of the genus Micropteryx, to be found in Ireland. The species pictured is Micropteryx calthella and is often to be seen feeding in the flower parts of the creeping buttercup, Rannunculus repens.