Deltote pygarga

The forewing is white, suffused with fuscous and black. Its wingspan measures 20–26 mm. Both the inner and outer lines are double and blackish, and the space between them is filled with grey. The round orbicular spot and the kidney-shaped reniform spot are grey, with paler outlines, and black scaling runs between them and follows the reniform.

The grey-brown claviform spot is edged with white at its end and followed by black scaling. A pale submarginal line sits in front of dark shading that thins toward the inner margin. In the lower half of the wing, the area beyond the outer line is more or less white. The hindwing is fuscous with a whitish fringe.

The form albilinea has much stronger dark shading before the submarginal line. This leaves the white area beyond the outer line as only a narrow band from the costa to the inner margin. In the form albomarginata, weaker shading lets the white reach the costa as a broad band.

The form gueneei, described from south-west France, has wings suffused with rufous, a nut-brown tone that gives it a very different look from the typical white form.

The species occurs throughout Europe, including Scandinavia. In the south, it is found in the countries bordering the Mediterranean, including some of its islands. Eastward, its range extends across Asia Minor, northern Iran, Afghanistan, southern Siberia and Central Asia, reaching China, Sakhalin, Korea, Japan and Taiwan.

In the Alps, the moth is found up to about 1,000 m. Its habitats are not described in detail in the available sources, but its wide spread across varied climates in Europe and Asia shows that it tolerates many conditions.

Records of adults are concentrated in late spring and early summer, with the strongest peak in June and a close second in July. Fewer records appear in August and September, and very few in the cooler months. This pattern reflects when the moth is most often seen, not how many individuals exist.

The larvae of Deltote pygarga serve as hosts for the tachinid fly Ceromya silacea, which attaches to them. This parasitic relationship links the moth to a second insect and affects the survival of its immature stages. Through this role, the moth forms part of a food chain in which a parasitic fly depends on its caterpillars.

The moth's wide range across Europe and Asia suggests that it is an established member of many woodland and open-country communities. Its caterpillars and the flies that parasitize them form a small but continuous link in these ecosystems.