Simacauda dicommatias


Simacauda dicommatias is a moth of the family Incurvariidae found in South America. It was described by the
English amateur entomologist, Edward Meyrick in 1931. The larvae are leaf miners and feed within the leaves of Chilean myrtle. In 2020 leaf mines were found at Trengwainton Garden, Cornwall; the first known occurrence in Europe.

Life cycle

;Ovum
Eggs have not been observed but are likely to be inserted into the underside of a leaf of Chilean myrtle, preferring new growth towards the end of a stem.
;Larvae
The larvae mine the leaves, initially in a long gallery filled with black frass and often cross the midrib. The mine terminates in a small, irregular blotch often at, or near the edge or tip. Larvae then leave the mine making a larval case from the blotch; it then makes a further two cases from leaves. In Cornwall the species is univoltine with tenanted mines found in late March, late June and in the autumn. Larvae have not been found in Argentina or Chile.
;Pupa
The larva pupates in the third case which, is away from the feeding area and attached to the underside of a leaf.
;Imago
Simacauda dicommatias is similar to Psychoides filicivora and care should be taken when recording either species in Cornwall where both larval foodplants occur.

Food plants

In Cornwall, larvae have been found at twenty-six sites on Chilean myrtle. At one site cases were also found on white Chilean myrtle, and another on an unidentified Myrtaceae, but could be Myrceugenia ovata.

Parasitoids

So far, two parasitoids have been found in Cornish larval cases. Pnigalio soemius was reared from a larval case found at Trelissick in December 2020 and Enytus apostata, an ichneumon found in a larval case at Trengwainton Garden in June 2021.

Distribution

Simacauda dicommatias is native to temperate Andean forests in Argentina and Chile. In 2020, larval feeding signs were found in Cornwall, Great Britain; the first known record of this species for the UK and mainland Europe.