- Subfamily: Dichomeridinae
- Wingspan: 20-24 mm
- Flight period: may - Oct
- Spread: Common
- Host plants: Convolvulaceae
The Helcystogramma triannulella is a moth of the Gelechiidae family, with a wingspan of 20-24 mm.
It is widespread in a large part of the Palearctic ecozone; present in Europe with the exception of Ireland, Great Britain, Holland, Denmark, Scandinavia, of the Baltic region and western area of the Balkan peninsula. *
In Italy it is absent from Sicily. *
The front wings of the Helcystogramma triannulella are elongated almost rectangular with the apex at 90 degrees. The background color is earth brown with darker streaks between the veins. Each of the front wings has 2 disc stigmata each with a small ring of scales light almost white, a dark shade often joins the two stigmata. other spots of almost black brown color are present along the margin.
The hind wings are translucent white, with brown shades along the edge and veins, fringed and with an elongated apex.
The long, curved palps are brown in color. Head, thorax are brown, the abdomen is brownish.
The Helcystogramma triannulella is polyvoltine with flickers from May to October. Sometimes the adult has a strange behavior: he pretends to be dead by turning around completely showing his abdomen and legs.
The larva has the first four brown / black segments between the first and second there is a thin white band, the following segments are white and have two brown / black dorsal lines from which lateral diagonal lines are branched, the head is ocher / brown colored. The caterpillar is decidedly mobile, and passes the trophic activity hidden in a folded and rolled flap of leaf through silky threads, from which it emerges to feed. ***
The larvae of this moth can be found on some Convolvulaceae such as Ipomoea batatas, Convolvulus arvensis, Calystegia sepium and Calystegia japonica.
* Lepidoptera mundi https://lepidoptera.eu/ - Fauna Europea https://fauna-eu.org/
** Bestimmungshilfe für die in Europa nachgewiesenen Schmetterlingsarten - http://lepiforum.de/
*** Plant Parasites of Europe leafminers, galls and fungi - https://bladmineerders.nl/