Chondrostega vandalicia (Millière, 1865)

Host plants:
The larvae are polyphagous on herbs and grasses near the ground. In the Spanish Sierra de Gredos young larvae preferred Rumex acetosella and various freshly sprouting grasses.

Habitat:
Chondrostega vandalicia inhabits nutrient-poor, dry pastures, open Genista grassland and other grassland or dwarf shrub habitats, often on plateaux or tops of medium-high mountains. It is important that there are enough low-growing, gappily vegetated grassy and herbaceous spots between the small shrubs. Chondrostega vandalicia mainly occurs between 700 and 1600m. In the Sierra de Gredos I found several population between 1400 and 1600m.

Life cycle:
The adults appear between late July and well into September. The wingless females climb stems of grasses, herbs and especially dwarf shrubs such as Genista an lay their large egg batches there. The males often rest with wings folded on the back. But most of the time they are strong fliers searching for females.
The larvae live from late September to April or May. Their time of development fits perfectly into the sprouting time of fresh grasses and herbs between autumn and spring and avoids the dry summer. The larvae are gregarious in the first instars. They spend the nights and bad weather together in 5-25 cm height on old dead blades or dry fruit stands of herbs. There they also moult. In the morning sun they descend to the ground to feed. In winter, development is often interrupted by snow and frost. Then the larvae hide in the grass layer or litter. In mild weather they feed again and rest gregariously on dry fruit stands etc. From February, development accelerates due to increasing sun power.
In the first instar the larvae are uniformous black-brown. Later on light and reddish colours join in the hairs. In the later instars additionally the typical red hair warts appear. Mature larvae also rest at night or bad weather on old fruit stands or blades, but then usually singly. Pupation takes place in a dense ovoid cocoon relatively deep in the soil.

Remarks:
Chondrostega vandalicia occurs in the central and partially northern part of the Iberian Peninsula, northwards approximately to the Ebro valley (Zaragoza). In the south (Andalucia) it is replaced by the closely related taxon Ch. escobesae. Other closely related species occur e.g. in N-Africa.