Moths to look out for in August

MAGPIE MOTH 

This is a very distinctive moth with black and a few yellow spots on a white background. It has a single generation in the summer and will come to light or can be seen resting flat on foliage during the day. It’s about the size of a Gatekeeper. Its larval foodplants are many hedgerow shrubs and fruit bushes.

It is a common resident, widespread, and undergoing an expansion of its range in northern Scotland.

SMALL MAGPIE

This moth, in spite of its name and black and white pattern, is no relative of the previous moth. It’s nearly half the size of the Magpie and is a member of the Crambiidae or Grass Moth family. These are ‘Micros’ although the Small Magpie is one of the larger Micros.

The ‘micros’ are so named not so much for their size but  for their position in the taxonomic ordering of moths and butterflies; they are more primitive in the structure of the adults, some of whom do not even have mouthparts.

You can see from the pictures these two moths shouldn’t be confused.

The Small Magpie is also single brooded and can be seen at light and disturbed from foliage any time between May and September.

Its caterpillar feeds inside the folded up leaf of nettles, Woundwort and Mint. It is common and widespread.

COMMON RUSTIC

This species is extremely variable. Four of its forms are shown here.

To complicate matters further, it was decided in 1983 that in fact it was two distinct species but identifiable only by ‘gen.det.’ (genitalia dissection). This second species, the Lesser Common Rustic, is equally variable! The species therefore, unless gen.det. is performed by an expert, is now recorded as Common Rustic agg. (agg. being short for ‘aggregated or combined species)

Both species are single-brooded in July and August, will come to light and can also be seen feeding on flowers.

Because the Lesser Common Rustic is much less identified as a true species, the knowledge of its distribution is still very incomplete. The distribution map shows the occurrence of the aggregate species as common and widespread.

The caterpillars of both species feed in grassland.

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