The larva most often develops on Stachis (= Betonica) officinalis. In the higher altitudes of the southwestern Alps the caterpillars live on Stachys pradica (= hirsuta), which is very similar to Stachys officinalis.
In Central Europe Carcharodus flocciferus lives in wetland complexes (fens) with nutrient-poor, low growing and drier areas. The insect still occurs in Germany only at the foothills of the Alps from Lake Constance to Lake Chiemsee.
In the Southwestern Alps Carcharodus flocciferus is apparently more common at higher altitudes (well correlated with the distribution of Betonica pradica). I found the butterflies at 1600 - 2200m above sea level both in the Italian Alps near Cuneo and at almost every pass in the French Alpes-De-Haute-Provence and the Hautes-Alpes. At the Col de Var numerous ovipositions on Betonica pradica on low growing, drier and raised spots were observed within mucky areas as it is often also the case in Central European fens. In the northern Alps Carcharodus flocciferus does not occur in the true mountain region above 1200m above sea level. Here also lacks Betonica officinalis. Betonica pradica occurs more in the Southern and especially Southwestern Alps.
In general a single generation flies in June and July. Occasionally a very partial second generation appears in August/September. Eggs are laid on the upper leaf surface of small, mostly sterile plants of Betonica officinalis, where the caterpillars create small housings. Here they partially gnaw the leaf stem, so that the leaf bags are often characterized by wilting and are easily noticeable. In the spring the mature caterpillars can be found mainly in May. Sometimes concentrations of larvae (each singly in its own shelter) occur within the wetlands at elevated, low growing places that are more reminiscent of dry grassland sites. Pupation takes place in a webbed shelter between leaves at the food plant.
Endangerment: threatened with extinction
This species is threatened with extinction in Central Europe. Previously the main causes were mainly reforestation, reducing of site size (intersection with corn fields) and intensification of wet meadows. Today it is more the eutrophication of the remainders, felting, road construction, improper maintenance measures, radical ditch clearances etc. Even today sometimes roads are built through the last precious fens.
Carcharodus flocciferus is distributed from Morocco (very local) across Central and Southern Europe (especially in mountainous areas) and spreads to the Altai.