Insects and Invertebrates of Mt. Daisen
Mt. Daisen’s many ecosystems support a diverse population of insects and other small invertebrates. Over 120 species of butterflies have been recorded in the mountain’s secluded fields of alpine blossoms. At lower elevations, particularly along the trail to the Amidadō Hall, the trumpet-shaped blooms of harlequin glorybowers (Clerodendrum trichotomum) are often visited by several species of swallowtail. In the grasslands near the summit, you might see the elegant blue-and-russet chestnut tiger (Parantica sita), boldly striped Japanese luehdorfia (), and translucent-winged glacial Apollo (Parnassius glacialis). Unfortunately, a decline in habitable areas has led to the disappearance of two former inhabitants, the brush-footed butterfly (Melitaea protomedia) and the false ringlet butterfly (Coenonympha oedippus).
Around 1,000 beetle species are found on Mt. Daisen, among them carabid beetles, chafer beetles, and tiger beetles. Several large species of stag beetle are also found in stands of Japanese oak and Japanese cedar. In addition to the beetles, you might encounter a female spider wasp (Anoplius samariensis) dragging a paralyzed spider back to her burrow. After stinging her victim, the wasp lays an egg on it, ensuring that the newly hatched larva will have a ready meal.
Heavy rains tend to bring out other invertebrates, some of which are striking in appearance. The handsomely striated land snail Euhadra sandai daisenica is native to Daisen, while another land snail, Aegista vulgivaga, has thick hair sprouting from its shell. Rain might also encourage an appearance by the giant earthworm Pheretima sieboldii, which can reach 30 centimeters in length and live for up to two years.
