The largest butterfly found in the Islands, measuring from four to four
and a half inches across the wings.
The larva is very bright in colour, having transverse bands of blackish
violet, gold, and white alternately. It has four black horns or fleshy
spikes along its back, and when full grown measures about two inches in
length, and it is rather stout and smooth. The pupa, green when first
turned, and suspending itself by the tail only, has a bright gold band
half-way round its base, and a series of gold spots encircling its
head. Shortly before emerging to a butterfly, it turns to a dark brown.
The caterpillar never suspends itself to the plant on which it feeds,
but goes to some of the higher grasses near it, or it prefers still
better a mallow plant, from the leaves of which as many as sixteen
beautiful bright green and gold chrysalides have been seen hanging,
forming quite a picture under the illumination of the glorious sun of
Teneriffe. It lives and feeds gregariously on the “Arbol de Seda,”
[4] a plant bearing a very bright red and gold flower. Many specimens
were reared from quite small caterpillars in the breeding-cages. They
were easy to keep, but especial care must be taken in providing them
with fresh food, and great attention ought to be paid to ventilation,
or some disappointment may be experienced in the number that die during
the pupa state for no apparent reason. A little of the morning sun is
beneficial to them, as they are found, when in a natural state, in the
most sunny localities.
[4] Asclepias cuvassavica.
A brood seems to emerge about every three months in most years from
February to September. The butterfly frequents flower-gardens and
fields near the coast, not often being found more than seven or eight
hundred feet above the sea. It is of a rich orange tawny colour, rather
heavily veined with black or dark brown. All four wings have a broad
black border, with two lines of whitish yellow dots along the margin.
There is a large apical patch of blackish brown on each fore-wing, with
seven large yellow and white spots on the tip. There is not a great
difference between the upper and the under side, except that on the
latter the white marginal spots are larger, and there is more white on
the black-feathered body.
The insect looks splendidly bright and flashing as it soars along with
a steady flight from tree to tree on the “Carretera,” and it must
be quickly netted, or it soon rises out of reach. These butterflies
are distasteful to birds, as also are the three following varieties
belonging to the same family. For this reason the family of Danais
is “mimicked” by butterflies of other species, the butterfly next
described (Danais Chrysippus) being, for instance, copied closely by
several African and Indian species of butterflies and even some moths.
The Danais Plexippus is a very common butterfly in North America, and
has within the last few years become widely dispersed, some specimens
having been found in England in 1877 and subsequently.