CHAPTER XXVIII.
Purple Emperor.--His Taste for Carrion.--Wood-pecker.-- Blue and Small Copper Butterflies.--Buff-tip Moth.-- Moths at Ivy.--Strange-looking Caterpillars.
One hot August day Frank and his faithful follower Jimmy were strollingarm-in-arm along the lanes to call for Dick. Presently they came uponhim engaged in no very pleasant occupation. Holding his nose with onehand, with the other he was drawing along a dead dog by means of a longbramble twisted round it. The dog was highly odoriferous, and Frank andJimmy kept at a distance while they asked him what he was doing thatfor.
"I saw a purple emperor butterfly flying round the top of one of theoaks in the park. It is impossible to catch it with a net, but I haveread that these butterflies have a taste for carrion, and will come downto it; so I just fished about until I found this dead dog, which I meanto lay under the tree as a bait."
"Are you sure it was a purple emperor? They are very rare here," saidFrank.
"Oh yes, I saw the purple of its wings shining in the sun, and it was solarge, and it flew about the tops of the oaks, and then flew higherstill out of sight."
The purple emperor is looked upon as the king of English butterflies. Itis a large insect, with wings of dark purple bordered with white, whichvary in colour like the material known as shot silk, and in the sunlightgleam most beautifully. The males only have this splendid purple glosson their wings. The females, though larger in size, have wings of adull brown. The purple emperor takes its station at the top of thetallest oak and rarely descends to earth. The female is morestay-at-home than the male, and is very rarely caught. The insect wouldbe far oftener seen than caught if it were not for its habit ofalighting upon carrion, and collectors take advantage of this low taste,and lie in wait for it, and catch it in the act. The caterpillar is aplump creature, with a tail running to a point, and a pair of horns ortentacles on its head. It is bright green in colour, striped with yellowdown each side, and it feeds upon the willow. In the south of Englandthis butterfly is not uncommon, but as you go north it becomes rarer.
Frank and Jimmy accompanied Dick to the park where the oak-trees were,keeping at a respectable distance to windward of him. The carcase wasdeposited beneath the tree where Dick had seen the purple emperor, andthey sat down behind another tree to wait the course of events. Twohours passed away without any sign of the butterfly, but time was noobject with the boys, who found it pleasant enough to lie on the coolgrass in the shadow of the oaks, and listen to the murmur of woodlandsounds. Squirrels and rabbits played about them, and birds fluttered inthe trees overhead. The cushat uttered her sleepy moan, and then woke upand flew away on lazy wing to the corn-fields, whence came the sound ofthe sharpening of scythes. The rattle of the woodpecker tapping thehollow trees was the loudest sound which disturbed the silent, broilingafternoon. The three friends were stretched on the ground talkingquietly, and half disposed to doze, every now and then casting glancesat the dead dog. Suddenly down a lane of sunlight there fluttered ashimmering purple thing which settled on the carcase, and stayed there,opening and shutting its wings, and sending scintillations of purplelight through the green shadows.
"There it is!" said Dick excitedly, and he got hold of his net.
"Don't be in a hurry, Dick; wait until it feels secure and gorges itselfa bit," said Frank.
Dick listened to his sound counsel, and waited as patiently as he couldfor a few minutes, and then he raised his net, and with a single leapreached the spot where the carcase lay, and brought the net down overdog and butterfly together.
GREEN WOODPECKER.]
"I have got it!" he exclaimed.
"That's right; and you have got a lot of maggots in your net as well,and stirred up the stench most tremendously. Make haste and kill thebutterfly and come away, or you will catch a fever," said Jimmy.
BLUE BUTTERFLY.]
The gorgeous insect having been secured in Dick's collecting box, theywent off in search of other prey. On a common just beside the wood theyfound abundance of the beautiful blue butterflies, which shone likeflakes of summer sky, and also the small copper butterfly, which rivalsthe most brightly burnished copper in its sheen. These were playingabout in the greatest abundance, the small coppers settling on a blueflower, or a blue butterfly on a red flower, forming most artisticcontrasts of colour.
THE HAUNT OF THE PURPLE EMPEROR.]
From its throne on the top of a tall nettle, where it sat fanning theair with its black, crimson-barred wings, Dick captured a magnificentred admiral, and shortly after another of the same species. Gorgeous asthe upper surface of the wings of this butterfly is, the under side isquite as beautiful in a quieter way, with its delicate tracery of brownand grey.
While Dick was setting the butterfly in his box, Frank leaned againstthe trunk of an oak-tree, and as he did so he caught sight of a mothwhich was resting upon it. It was a large thick-bodied moth, and Dick onbeing appealed to said it must be a buff-tip moth, from the largepatches of pale buff colour at the ends of its wings. Frank said,--
"I should not have seen that moth if my face had not almost touched it.Its colour suits the tree-trunk so admirably that it looks just like apiece of the rough bark. I suppose it knows that, and rests on theoak-tree for safety."
"Yes," said Dick; "I have read that many moths and butterflies are solike the substances on which they rest by day, that they can scarcely bedistinguished from them, and of course there must be a meaning in it.The lappet-moth looks exactly like two or three oak-leaves stucktogether, and its wings are folded in a peculiar manner, so as to keepup the delusion. There are caterpillars too which can stiffen themselvesand stand out on end, so as to look like sticks."
"It is the same with birds'-eggs," said Frank. "Those which are laid onthe ground without any attempt at concealment are of such a colour thatyou can hardly see them. For instance, take a partridge or pheasant. Howlike their eggs are in colour to the dead leaves of the ditch where theynest. The same with the lapwings, and all the plover tribe. Coots andwater-hens' eggs are so like their nests, that at a little distance youcannot tell whether there are eggs in or not."
"I wonder," said Dick, "if birds take any pleasure in the prettiness oftheir eggs. If so (and I don't see why they shouldn't), there is areason why birds which build in bushes and branches of trees should havepretty coloured eggs, as they have, and why birds which build in darkholes should have white or light-coloured eggs, otherwise they would notsee them at all."
"That is a very ingenious theory, Dick, and it may have something oftruth in it," answered Frank.
That night was a still, warm night, and the moths were out in abundance.As soon as it became dark they all went out with a dark lantern to huntthem, and they were very successful. As they were returning home theypassed by an old wall covered with huge masses of ivy. Dick going closeto it said,
"Do look here. There are hundreds of tiny sparkles. What can they be?Why, they are the eyes of moths. The ivy is covered with the moths,feeding on the flowers. Look how their eyes gleam." And truly it was amarvellous sight. When they turned the light of their lantern on themthey saw that the moths were busy with a curious silent activity, flyingfrom flower to flower, sipping their sweets.
"There are so many that I hardly know how to set about catching them,"said Dick. "Many of these must be rare and many common."
"Sweep the face of the ivy all over with your net as rapidly as you can,and keep them in your net until we get home, and then we can kill andpick out all that you want," counselled Frank.
Dick followed his advice, and with a dozen rapid sweeps of his net heseemed to have filled it. Closing the net by turning the gauze over thering, they walked quickly back to the boat-house, and carefully closingthe door and window, they opened the net and let them all out into theroom, and then caught them singly. In a couple of hours they found thatthey had secured about fifty specimens, comprising twenty differentspecies.
During the summer a strange creature which fed on the potato pl
ants hadmuch frightened the country people, who thought it a sign of a comingplague. It was a large caterpillar, of a lemon-yellow colour, with sevenslanting violet stripes on each side and a horn on its tail. The peoplein the neighbourhood of Hickling, knowing that Frank and his companionswere fond of collecting such things, brought some to them, and by thismeans they became possessed of more than thirty specimens. They were thelarvae of the death's-head moth, the largest of all our British moths. Itis remarkable not only for its size, but for two other things, each ofwhich is very curious. On its thorax it has a perfect delineation inwhite of a skull, or death's head, with a pair of cross-bones below it.In addition to this singular mark, it--and it alone of all our moths andbutterflies--has the power of making a squeaking noise, which it doeswhen it is touched or annoyed. How it makes this noise no one seems toknow. At least there are so many conflicting opinions that the mattermay be said to be still in doubt.
The boys fed the larvae on potato-leaves put in a box in which there wasplaced about six inches of earth. When the larvae had finished theireating, they dived into this earth and turned into the pupae state. Inthe autumn the perfect moths came out, but only about half of the numberreached the final stage. The others died in the pupae state. However,Dick had plenty of specimens for his cabinet and for exchange.