MONARCH OF THE BUTTERFLIES.

Auckland Star, Volume LXX, Issue 303, 23 December 1939, Page 4 (Supplement)

MONARCH OF THE BUTTERFLIES.

Monarch butterfly began its

great flights over a century ago e p when it migrated from its original home in South America to Central America and the United States. Then, like Columbus, who set out to discover a new world, the Monarch crossed the oceans. We know that these wanderers first appeared in Tonga about the middle of the last century, in Samoa a little later, then Lord Howe Island. Melbourne and other parts of Australia followed, then the greater part of the Pacific Islands became colonised by these beautiful migrants from America. From the tropics the MonaVch slowly extended its range southward, and is now known to many parts of the world. A more or less gregarious insect, the 'Monarch in its native country migrates in great numbers either north or south as the season dictates; the butterflies settle in swarms in the trees at evening, resting until the resumption of the journey next morning. Around the American coasts the Monarchs are seen from time to time coming in from the sea, flying at a height of about 400 ft, and almost out of sight. As soon as they are over land they descend to within a few feet of the ground. During the past nine years many have aslied me the duration of a Monarch's life. Under special conditions the butterfly can live for jver six months, but an life is three months. This is considerably more than the life span of the common butterfly. They will, if necessary, cover hundreds of miles in search of food plants upon which to lay their eggs. If a male finds a food plant he sends out an S.O.S. in scent from the scent pouches on his hind wings, then waits for his mate to find him. This remarkable fact is considered to be correct by those who have watched proceedings at Titirangi. These food plants, swan and asclepias, contain a special acrid piilk sap, which permeates the bloodstream of the caterpillar, chrysalis and

butterfly, and renderg them distasteful to birds. The New Zealand whiteeye will, however, eat the eggs and the very young caterpillars, so plant your food plants away from the trees which attract these birds.

The life cycle , begins with the butterfly itself. The female lays her <?ggs on the underside of the food plant leaf, generally only one egg to each leaf. In about eight days, or according to air temperature, the egg hatches, and the caterpillar begins to eat the green matter of the leaf. Every five or six days the caterpillar casts its old skin and head cap, this process taking about two days. During this time it is firmly anchored to a leaf or stem by silk, and so helpless is it if attacked by enemies that Nature has provided it with a pair of shiny black false eyes. These, with the two horn-like antlers standing out behind the head, and the old head cap itself sticking on the nose of the caterpillar's new and larger head, give it an appearance of a savage bull, which keeps small enemies at bav.

When the skin is loosened from the body the caterpillar walks out, leaving it anchored with spk to the twig. It then sheds the old head cap and finds itself ready for a hearty meal. It grows rapidly until another five days have passed, when it prepares to cast another skin, and so on until the third skin is sloughed. The new coat is then of a different colour, and the caterpillar grows rapidly until it reaches about 2Jin in lehgtli. It is now about four weeks old. Ceasing to eat, the caterpillar has 24 hours' rest, then commences to spin a silk mat on whatever object to which it intends to secure itself.

In the centre of the mat the caterpillar makes a silk ball into which it securely fastens its hind feet. It then loses all power in the other feet and hangs head down for from 24 to 48 hours according to air temperature. During this period the caterpillar organs, are turning into the organs of a butterfly. When flesh in the front pair of antlers recedes into the body, leaving them as limp as empty stockings, the creature is ready to cast its last caterpillar skin and show the green chrysalis inside. TheTe commences a kind of shrugging motion which tightens the skin to bursting point, then the skin splits at the back of the head and up and back. The front part then starts slowly sliding and it will be notieed at this stage that the caterpillar head now contains the beautiful pair of antennae of the

My object in writing this article is to explain as clearly as possible the complete life-cycle of this most interesting and beautiful butterfly. Here are some points which have never previously been explained, especially one outstanding feature, the study of part of which under a microscope is truly enthralling.

IN the accompanying article Mr. T. S, Skeates, of Titirangi, Auckland, narrates the fascinating life story of the,beautiful and unusual Monarch butterfly. Mr. Skeates was the first to introduce the butterfly into Auckland, and has been observing it for nearly ten years. Consequently he is a recognised authority on the Monarch, and "Enzed Junior" is proud to present this delightful article from his pen. He is especially keen that the young readers of this paper should' realise that the Monarch is a valuable and beautiful addition to New Zealand's fauna, and as such should be cultivated . . . not as an item in a butterfly collection, but as a lovely, harmless living creature which does much to add to the beauty of our gardens, parks and countryside.

future butterfly. As the skin and head case slide upwards these antennae are beautifully uncoiled from inside the head cap and laid in correct position along the front part of the thorax.

j When the skin reaches the first | pair of caterpillar feet, the flesh, inside them slips back into the body, •thus allowing the skin to travel on upwards until four of the five pair of feet have been thus passed. When the skin reaches a slightly higher point a rgost wonderful performance takes place. Don't forget that at this stage the chrysalis is still holding on to its ball of silk by the last pair of caterpillar feet. During the 24 or more hours in which it was changing into the chrysalis, a wonderful tail was created inside the caterpillar skin. This tail is of a bone-like substance, and on the end of it there are from 100 to 200 beautifully made hooks of unique design. (See sketches.)

This new tail is called the cremaster. (See fig-.) It has been drawn down from among the maw of crumpled skin, and is sticking out just below it. The creature now rocks to and fro and expands its abdomen in a concertina-like movement; then it reaches up and bores the minute hooks securely into the ball of silk. As soon as it has done this it releases the grip of the last pair of caterpillar feet. These slip back into the body, leaving the chrysalis hang"ing by its new tail to the ball of silk. When the old skin is quite free it is gripped by some of the abdominal segments of the chrysalis and cast completely away.

The chrysalis hangs in this position for 14 days or more. (The time varies according to temperature. Sometimes it is 21 days in late summer, and even longer in autumn.) When within " about four days of emergence the chrysalis changes colour, becoming daily darker. It is finally a blue-black, with the red wings showing through the thin casing. As soon as the sun becomes warm and the temperature reaches about 70 degrees the butterfly emerges in all its beauty. This may take place any time after 8 a.m. The wings will develop to full size in about half an hour, but the insect will not be able to make a flight until after four hours in summer, and accordingly more as the weather

grows colder. When eventually on the wing the butterfly grows stronger each day until it k able to cover hundreds of miles daily.

In Fig. O, which is greatly enlarged, you will notice five pairs of black dot's up near the tail with the ere-

master hook*. They represent the black sealed holes in the contracted aUlomen where the five pair of caterpillar feet disappeared into the body. This sketch represents the complete abdomen when contracted after the chrysalis has formed into shape. Figures A, B and C give some idea of the cremaster hooks and their shapes though, of course, they are here very greatly enlarged. You would hardly believe that inside that beautiful jewel-like green and gold chrysalis there is a pulse beating like a little clock, but under certain condition* it can be plainly seen.

I have proved beyond doubt that these butterflies can live upwards of three months. Caterpillars can be easily bred on the food plants (swan and asclepiae curassavica), and the butterflies, when on the wing, add great beauty to any park, garden or countryside. The butterfly belongs to our New Zealand fauna, and it would be a great wrong to take the life of such a wonderful creature. Therefore, on no account ever kill a Monarch.

I strongly advise all breeders of the Monarch to keep the caterpillar on their food plants until 21 n long, no matter whether therrf is sunshine, dew or rain. This will enable the caterpillar to grow larger and stronger, and render the future butterfly the sturdy creature it need# to be for its long flights.