Description: Wingspan 19-20 mm. A small inconspicuous species that is most active in sunshine. Forewings are a mixture of olive and purple brown. Antemedian line not visible, post median line broad ranging in colour from light to dark purple brown. Hindwings similar in colour to forewings. Mid-April to mid-June.

World Distribution: Eurasiatic; common and widespread on heaths throughout western Europe as far north as Finland.

Irish Distribution: Widely distributed but local; recorded from all counties in the past. In recent times it has been more commonly encountered in southern counties, especially in Fermanagh where it has been seen frequently in some well-recorded grassland sites such as Monawilkin. In the east it has been found on the lower slopes of the Mournes at Leitrim Lodge and Annalong Wood. It has not been recorded from Londonderry since 1972. Its resemblance to a small micro moth makes it easily overlooked by all but experienced recorders.

Ecology: A small dayflying species found in upland and lowland bogs, heaths and limestone grasslands. The adults normally fly rapidly in sunshine, usually settling on bare ground or short vegetation. They are generally wary and difficult at times to approach. The larvae feed from July to September on Common Milkwort Polygala vulgaris. It overwinters as a pupa.

Key Identification Features:

• Small size
• More obvious in sunshine
• Often seen resting on bare ground

Distribution Map from NBN: Phytometra viridaria at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Phytometra viridaria at iNaturalist World Species Observations database.