Hungarian Glider Neptis rivularis, Aggtelek, Hungary – Peter Bruce-Jones
Introduction
The genus Neptis, together with Pantoporia and Athyma can be regarded as a ‘sister’ genus to the holarctic Limenitis and the neotropical Adelpha.
There are about 170 Neptis species, of which about 65 occur in Africa, 40+ in the Palaearctic, 50 in the Oriental region and 6 in the Australian / Papuan region. The genus is unsatisfactorily split into several loosely defined groups. It is likely that phylogenetic analysis will eventually lead to each of these being classified as a separate genus or sub-genus.
The upperside ground colour of a typical Neptis is dark brown or blackish, with a long white streak in the forewing discal cell, and a distinctive arrangement of white bands and spots. In some species the white markings are replaced by yellowish or orange. The pattern is repeated on the underside, on a plain orange-brown ground colour.
Neptis rivularis is distributed from Switzerland and northern Italy to Siberia, China and Japan.
Habitats
This species is found in damp deciduous woodland glades at elevations between sea level and about 2000m according to locality.
Lifecycle
The egg is laid singly at the tip of leaves of the foodplants. The larva sits at the tip of the leaf facing inwards and eats chunks either side of the mid vein. It rests and hibernates in a shelter formed by rolling the tip of the leaf into a tube. The larval foodplants include Spiraea, Aruncus and Filipendula and possibly other Rosaceae.
Adult behaviour
Males imbibe mineralised moisture from damp ground, and spend long periods perching on the foliage of trees and bushes where they await passing females. Both sexes imbibe aphid secretions ‘honey-dew’ which coat the upper surface of leaves. The flight is slow, precise and graceful but if alarmed the butterflies can move rapidly.