About Carcharodus alceae (Esper, 1780)
Carcharodus alceae, commonly called the mallow skipper, has a wingspan of 28–32 mm. The background of its forewings is pinkish brown, marked with approximately square brown patches, short white transverse stripes running from the wing edge, and clear patches on the discal area. Its hindwings are brownish or grey-brown, with prominent brighter spots on the underside. Males have no hair tuft on the underside of their forewings. The tips of its antennae are cherry brown. The eggs of this species are yellowish and hemispherical, with a surface covered in elongated warts connected by low ribs, giving the egg a prickly appearance; eggs turn red as they develop. Fully grown caterpillars reach a length of about 23 millimetres. They are dark gray, covered with small white dots and short white hairs, and have a black head marked with yellow spots separated by black stripes. This species is very similar to the Marbled skipper (Carcharodus lavatherae) and almost indistinguishable from the False mallow skipper (Carcharodus tripolinus). Distinguishing traits for Carcharodus alceae include its toothed hindwing edge and small "glass spots" (unscaled areas) on the black-brown base of its forewings. Males of Carcharodus alceae lack hair tufts on the underside of the forewings, which allows reliable distinction from Carcharodus flocciferus. This is a widespread, common species found from Western Europe east to Central Asia. Its recorded range includes most of southern and central Europe, northern Africa from Morocco east to Tunisia and Libya, the Middle East, Asia Minor, the Caucasus, northern India, Middle and Central Asia, the western Himalayas, and southern Western Siberia. In Europe, it occurs mainly in the Mediterranean region. In Germany, its regular distribution extends to Central Germany, reaching as far north as the Kyffhäuser Mountains. Records of the species in previously unoccupied areas of Central Europe clearly show that C. alceae is currently spreading. Mallow skippers prefer dry, warm, stony areas, wasteland, warm ruderal sites, and gardens, occurring at elevations up to 1,100 metres above sea level. In Bavaria, its altitudinal range extends from roughly 100 m to 600 m, with its main population concentrated in the Colline zone between 200 m and 500 m above sea level. Its habitats are a wide range of grasslands and ruderal meadows that support growing mallow species. In Middle and Southern Franconian Jura, it occupies irregular patches in limestone areas, sandy grasslands, ruderal embankments, and other thermophilic ruderal meadows. Additional habitats include fallow land (especially industrial wasteland), roadsides, and arable fields sown with seed mixtures. Oviposition also occurs regularly in gardens and on the edges of vineyards. In limestone grasslands, the species uses areas with patchy, disturbed vegetation, such as limestone rubble patches, seams, and marginal transition zones next to fields. Many observations over recent years have recorded the species in freshly cleared limestone grasslands over open bare ground, which temporarily supports increased growth of mallow species. The powerfully flying adult butterflies are able to colonize newly formed habitats very quickly, and often only a single mallow plant is enough to support a small population. For example, in the Neumarkt / Oberpfalz district of Germany, the species (both adult butterflies and caterpillars) has been detected in almost all larger grassland areas over the past ten years, though mostly at low density. Even though adult mallow skippers are strong fliers capable of rapid spread, they are most often observed close to their larval habitats. Easily recognizable folded and spun leaf structures called leaf bags are a clear indicator of this species' caterpillars. Because these caterpillars appear in gardens, their larval lifestyle was already known to Maria Sibylla Merian in the 17th century. It is common to find multiple caterpillars on a single plant at once. Mallow skippers lay their eggs on the upper surface of leaves of various mallow species, which gives the species its common name. The larvae feed mainly on Malva alcea, Malva sylvestris, Malva moschata, Althaea officinalis, Lavatera thuringiaca, and Hibiscus species. Which of these plants are preferentially used in a region depends mostly on the distribution and frequency of each species. Oviposition on Malva neglecta has been recorded at arid sites in the Middle Jura and on vineyard edges in the Steigerwald. On the embankments of the Rhine-Main-Danube Canal, Lavatera thuringiaca (which is abundant in this area) is accepted as a food plant. Additional recorded food plants include Althaea officinalis and Alcea rosea. In Bavaria, caterpillars can be found from May 12 to September 23. Their peak occurrence falls in the second half of August, and they are recorded almost continuously through this period, except for the last ten days of June and the first and last ten days of July. Fully grown caterpillars stop feeding, overwinter, and pupate the following spring. Caterpillars do not overwinter on their food plants, and their exact overwintering location is still unknown, though it is presumed to be in leaf litter. Adult mallow skippers feed on nectar from various herbaceous plants. Tall herbs, especially mallow species themselves, serve as nectar sources. Adults often suck moisture from damp spots on unpaved roads. The flight period of adult butterflies runs from April to October, varying by location. In Central Europe, the species usually produces two generations per year, flying in April–May and July. In southern areas, there are three or more generations per year. Flight times depend heavily on annual weather conditions, ranging from mid-April to early September. Individuals of the first generation are mainly observed in May. The transition between the first and second generation is gradual when viewed across all years, with the number of recorded butterflies dropping significantly in early to mid-June. More individuals of the second generation appear from early to mid-July, and this generation is usually much more numerous than the first. Butterfly records decrease again starting from mid-August.
