November Moths

Walking through the Churnet Valley Cowgutter Wood on Sunday 25th November  it had just begun to get dark.  Gradually moths started to appear. Soon the air was thick with them on this still, damp autumn evening. Masses of small grey shapes with a characteristic weak fluttering flight.  This mass moth gathering is an essential precursor to the summer food supply of birds at Coombes Valley. But perhaps most people associate moth watching with warm summer nights.

The  more familiar  caterpillars or inch worms are important in the diet of Great Tit, Blue Tit and Pied Flycatcher in the summer. The November  and Winter ‘Looper’ or Geometridae moths emerge in huge numbers in the autumn and winter to mate and lay eggs.  The eggs hatch to coincide with bud burst in the spring.

November Moth – Epirrita dilutata 

The November Moth is the most widespread of the three Epirrita   species in Staffordshire - all camouflaged shades of grey brown. The other two - Pale November Moth and Autumnal Moth are probably under recorded due to identification uncertainties.  Apparently Victorian collectors would hunt November moths with a butterfly net at dusk, a practice known as 'dusking'. 

Slightly smaller than the November Moth is the Winter Moth. As the same suggests the males of these species fly throughout the winter, but unlike the November moths the females are flightless.  The Mottled Umber is another winter emerging species with flightless females.  In the Natural history of Moths Mark Young says 'fatter flightless females' tend to occur in species occurring in cold northern climes  or on isolated islands where being blown into the sea might be a problem!

The advantage of winter emergence is a lack of predatory birds, bats or spiders. Most of these adult moths do not feed. However, Winter moths can have a significant impact on summer tree foliage.  The Mottled Umber's Latin name Erannis defoliaria gives a clue to a voracious spring and summer appetite.

Volunteer - Mark Preece