Eurois occultus (Linnaeus, 1758)


Eurois occultus: Adult (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Adult (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Adult (e.l. rearing, S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Adult (e.l. rearing, S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Adult (e.l. rearing, S-Germany, Kempter Wald, larva in October 2019) [S] Eurois occultus: Adult (e.l. rearing, S-Germany, Kempter Wald, 800m, larva in October 2019 [S] Eurois occultus: Adult (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Adult (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Adult (Grisons, Val Rosegg) [S] Eurois occultus: Young larva (W-Austria, Tirol, Kaunergrat, 1500m, September 2020) [S] Eurois occultus: Young larva (W-Austria, Tirol, Kaunergrat, 1500m, September 2020) [S] Eurois occultus: Young larva (S-Germany, Isny, October 2020) [S] Eurois occultus: Young larva (S-Germany, Isny, October 2020) [S] Eurois occultus: Young larva (S-Germany, Isny, October 2020) [S] Eurois occultus: Young larva (S-Germany, Isny, October 2020) [S] Eurois occultus: Young larva (S-Germany, Isny, October 2020) [S] Eurois occultus: Young larva (S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Young larva (S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Young larva (S-Germany, Isny, 700m, larva in October 2020) [S] Eurois occultus: Young larva (S-Germany, Isny, October 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Half-grown larva (e.l. rearing, S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Young larva (W-Austria, Tirol, Kaunergrat, 1500m, September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva in the penultimate instar (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva in the penultimate instar (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva in the penultimate instar (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva in the penultimate instar (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Half-grown larva in the end of the penultimate instar (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Half-grown larva in the end of the penultimate instar (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.o. rearing, S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Lech Valley near Forchach, larva in October 2017) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.l. rearing, W-Austria, Tirol, Kaunergrat, 1500m, larva in September 2020) [S] Eurois occultus: Larva (e.o. rearing, S-Germany, Oberallgäu, 1100m, larva in October 2018) [S] Eurois occultus: Larva after the last moult (Val Rosegg) [S] Eurois occultus: Larva after the last moult (e.l. Engadine, Val Rosegg) [S] Eurois occultus: Larva after the last moult (e.l. Engadine, Val Rosegg) [S] Eurois occultus: Larva (Val Rosegg) [S] Eurois occultus: Larva (Val Rosegg) [S] Eurois occultus: Larva (Val Rosegg) [S] Eurois occultus: Pupa (Val Rosegg) [S] Eurois occultus: Pupa (e.l. rearing, S-Germany, Kempter Wald, 800m, larva in October 2019 [S] Eurois occultus: Pupa (e.l. rearing, S-Germany, Kempter Wald, 800m, larva in October 2019 [S] Eurois occultus: Pupa (e.l. rearing, S-Germany, Kempter Wald, 800m, larva in October 2019 [S] Eurois occultus: Larval habitat (S-Germany, Isny, early November 2021) [N] Eurois occultus: Larval habitat (S-Germany, Isny, September 2020) [N] Eurois occultus: Larval habitat (W-Austria, Tirol, Kaunergrat, 1500m, September 2020) [N] Eurois occultus: Larval habitat (W-Austria, Tirol, Kaunergrat, 1500m, September 2020) [N] Eurois occultus: Habitat in the Engadine (Val Rosegg): open pine forest with rich undergrowth (May 2008) [N]

Host plants:
The larvae are polyphagous on herbs and especially small shrubs such as Vaccinium or Lonicera.

Habitat:
Eurois occultus is particularly typical of cool, bright, montane to subalpine or boreal coniferous forests, which have a well-developed understory of dwarf and other shrubs. But it occurs occasionally also in lower altitudes. In the northern foreland of the Alps it is often common on and around bogs in spruce forest or grassy edges.

Life cycle:
The caterpillar overwinters. In spring, it sometimes rests on the still quite nude twigs of Vaccinium during daytime. I found a half-grown larva in the Engadine at 2000m above sea level during the day concealed in the moss layer under Lonicera coerulea which twigs had eroded buds. The caterpillar is fully-grown in May or June, depending on the altitude. The moths fly from late June to August. In autumn (especially September to early November) the young larvae are easily nbeaten from the herb layer or from dwarf shrubs.

Endangerment factors:
Eurois occultus should not be especially vulnerable especially in the mountains, even if intense spruce plantations are hardly inhabited.

Remarks:
The distribution is Holarctic (temperate Europe, Asia, North America), but in southern Europe with only a few populations locally in the mountains.


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