The Marsh Fritillary (Melitæa Aurinia)
This species, of which several forms are represented on Plate 73, is subject to considerable variation in depth of colour, and also in size and intensity of the markings, in all localities. The varieties here referred to are more or less characteristic of the countries in which they occur. To mention all the forms, or even those to which varietal names have been given, would occupy more space than is available for the purpose.
Reddish-orange or bright tawny, veins black, breaking up the yellow or yellowish transverse bands; there are three or four transverse black lines, the first and second, counting from the base of the wing, not always distinct; basal area more or less suffused with black. On the under side the fore wings are fulvous, with faint traces of the upper-side markings; the hind wings are rather redder, especially on the outer half, and have yellowish markings, comprising some spots towards the base of the wings, a band beyond the middle, a series of black centred spots, and crescents on the outer margin. The above applies more particularly to the form of the butterfly occurring in England and Wales.
The Irish form known as præclara has the transverse band straw-coloured, the red colour is more vivid, and the black veins and cross-lines heavier; the area nearest the base of the wings is often blacker.
In a form occurring in Scotland, and known as var. scotica, the black is still more intense, and the straw-coloured markings are dull in colour.
The egg is pale brownish and very glossy. It appears smooth towards the rounded base, but is ribbed from just before the middle to the top. The eggs are laid in batches on leaves of scabious, chiefly the Devil’s bit (Scabiosa succisa).
The full-grown caterpillar is black, with a number of tiny whitish dots, each bearing a short black hair; short black spines are arranged in nine rows from ring four, the first ring is only hairy, the second and third have each two spines. The head is black, with a groove down the front and short hairs on the sides. The true legs are black, and the false legs and the under parts of the body are dull rust-coloured. The caterpillars hatch from the egg in June or July, and towards the end of August they construct silken webs, in which they establish themselves for hibernation. Early in March they recommence feeding, and under the influence of much sunshine feed up quickly. Besides wild scabious, they will eat honeysuckle and the garden kinds of Scabiosa. The chrysalis is pale buff, with orange points on the body; the wing-cases are marked with black and orange. The chrysalids are suspended from a silken web, which is attached to a leaf or drawn-together leaves. The early stages are figured on Plate 70.
Kane (Catalogue of the Lepidoptera of Ireland), referring to this species, remarks: “This butterfly has been known to increase so prodigiously that whole fields and roads became blackened by the moving myriads of larvæ. An instance of this was observed by the Rev. S.L. Brakey, near Ennis, Co. Clare, where he drove out to see a reported ‘shower of worms,’ and found as above described, the larvæ being so multitudinous in some fields that the black layer of insects seemed to roll in corrugations as the migrating hosts swarmed over each other in search of food. The imagines that resulted from the starved survivors were extremely small and faded in colour.”
These caterpillars are destroyed in great numbers by Hymenopterous parasites, chiefly Apanteles, and it is almost certain that a large percentage of those collected will prove to have been stung.
The butterfly is on the wing in May and June, and seems to affect damp meadows, marshy ground on the sides of hills, and such kind of places. It does not necessarily occur wherever its food-plant is abundant, but scabious is always found to be present in the haunts of the butterfly; so if we know that the insect occurs in a particular district we should probably get a clue to its exact whereabouts by noting the likely places in that district where the food-plant flourishes.
Although it has seemingly disappeared from various English localities where it was formerly common, the butterfly may be found in many parts of the British Islands, but it is local and does not occur northwards much beyond the Caledonian Canal.
Abroad it spreads over Europe to Northern Africa, and its range extends eastward through Asia to Amurland and Corea.
The fine butterfly next in order is regarded as a member of the Danainæ by most authors. Although its generic position seems to be established, its proper place in the classification of butterflies is still unfixed; and even the question of its trivial or specific name is not finally settled. According to Kirby, this butterfly is Anosia menippe, Hübner, and not the true Papilio plexippus of Linnæus, nor the P. archippus of Cramer. American authors, however, consider it to be the Linnean plexippus, and give menippe Hb. as a synonym. The species is here retained in Danainæ, but Holland places it in Euploeinæ and Skinner in the Family Lymnadidæ.