Few insects are so conspicuous, or have so magnificent an effect on the wing, as the Atalanta; its velvety-black wings, with their scarlet bands, white spots, and azure edges, presenting a bold contrast of colour that is seldom seen, and in its way cannot be surpassed. It is certainly a grand insect; and it seems to be quite aware of its own beauty as it comes sailing through the sunny glades, gracefully inclining from side to side, as if to show its colours to the best advantage. Perhaps its best aspect is when it sits upon a teazle-head, quietly fanning its wings in the sun; for the quiet purple and brown tints of the teazle set off the magnificent pure colours of the insect.
These brilliant colours are only found on the upper surface of the wings, the under surface being covered with elaborate tracery of blacks, browns, ambers, sober blues, and dusky reds, so that when the wings are closed over the creature’s back, it is hardly to be distinguished from a dried leaf, unless examined closely.
This distinction of tint often proves to be the insect’s best refuge; for, if it can only slip round a tree or a bush, it suddenly settles on some dark spot, shuts up its wings, and there remains motionless until the danger is past. The rough, brown elm bark is a favourite refuge under these circumstances; and it takes a sharp eye to discover the butterfly when settled.
Sometimes the creature is not quite so magnificent, and even appears shorn of its fair proportions. I have now such a specimen before me, which I found on a sandy bank, unable to fly.
My attention was drawn to it by observing a curious fluttering movement of the grasses that covered the bank; and on going up to the spot to see what was the cause, I discovered an Atalanta butterfly that had apparently lost both wings of the left side, and was endeavouring to fly with the remaining pair. Of course it could only make short leaps into the air, turn over, and again fall to the ground. Wishing to put it out of pain, I killed it, and on examination found that it had never been endowed with wings on its left side, and that those organs had still remained in the undeveloped state in which they had lain under the chrysalis case. Even the right pair had not attained their full development; but in every other respect the insect was perfect.
I suppose that the caterpillar must have selected too dry a spot for its habitation when it became a pupa; and that in consequence the pupa shell was so dry and hard that the butterfly could not make its escape in proper time, I have often seen similar examples in my own caterpillar-breeding experiences. There are also in one of my insect cases two specimens of the little white butterfly, which have met with even a worse fate; for they have not been able to escape at all out of the chrysalis, and so present the curious appearance of a chrysalis furnished with head, antennæ, wings, and legs. The cause of the disaster was probably the same in both cases.
The caterpillar of the Atalanta is shown on [plate D], fig. 4 a, and is a creature worthy of notice.
It is a well-known saying, that “what is one man’s meat, is another’s poison”; and the proverb holds good in the case of the Atalanta caterpillar. For its meat is the common stinging-nettle, which is, undoubtedly, poisonous enough to qualify any such proverb.
The colour of the caterpillar is green-black, and along each side runs a spotty yellowish band. Its general shape and appearance can be seen by referring to the figure.
After passing through the usual coat-changing common to all caterpillars, it begins, just before its last change, to prepare a spot where it may pass its pupal state. Its mode of so doing is very curious, and is briefly as follows:—