THE NATURALIST.

Otago Witness, Issue 2355, 13 April 1899, Page 54

THE NATURALIST.

WATHIDE NOTES. TO THE EDITOR.

Sir,— T find Mr Geof Air-Thomson's "Notes by the "Wayside" exceedingly interesting, if anything too good, as their rather philosophic tone mny be apt to keep others from recording their own notes. I have made lots of jottings in years gone by, but never made much use of them. So it has been, I have no doubt, with many another, and beyond being a ploature at the moment puch performances end where they begin. All the same very interesting, even valuable, results can be got if Witness reader? here and there were to send in brief notes upon plant and animal life as they see it, and accounts of episodes that come under their observation. The most delightfully enthralling book of English Natural History (the Natural History of Selborne) is little more than a bundle of such jolting.?, by Gilbert White, some large, some small, but all the products of a man of genius in this province. There may be few Gilbert Whites in New Zealand, or out of it, but there are many who could profitably follow in his steps in such a new, beautifid, and interesting loud. In course of time many new facts could not fail to be gleaned, and these would be of incalculable value to the coming natural historian of New Zealand, a personage bound to turn up before many years have passed. Than the Witness, penetrating penetratively to every part of the colony, as it weekly does, no newspaper, it seems to me, could be bettei fitted for kudos-earning work of this kind.

The eyes, even of those of us who seldom find our ways lead elsewhere than by dull city " waysideß," may occasionally light upon something out of the common. Even in the smallest of small gardens a vast deal is forever taking place in animal as well as plant life that stimulates curiosity and eggs us on to more pronounced inquisitiveness. Some years ago I had a small flowerpot or two in front of a house — we then lived in Dunedin. Even in that narrow space there was enough to be ee«n to nave occupied all the leisure at one's disposal if *o minded.

>')i,e moraing I stepped outside just at the rifj'ht moment to Eft* a curious occurrence thut I had often read about but never before been. *t was an Ichneumon fly attacking a large green caterpijlau, which, at the moment my eje fei: upon it, was in the act of dropping from the leaf on which it had been feeding, a trick habitually resorted to by certain caterpillares as a method of escape from birds and such foes as this one was vainly striving to elude.

The Ichneumon, even as it was borne to the earth along with its heavier victim, had already got its long ovipositor inserted in the caterpillar's Body. The natural feeding place of this fly's larvse is among the rich fatly mattei of Ihe caterpillar's lissues. Even as victim and foe fell togother the ova might have been passing from the deadly egg-lay-ing tube of the fly to the flesh of the doomed caterpillar. A vast number of caterpillars are thus done away with annually in every land. The victims, alarmed as they evidently are at the Ichneumon attack, never become aware of their actual doom. They may go on for weeks after receiving the fsdal injection, feeding and apparently growing well. When the time comes for them to end their active lives as larvae and become lethargic pupae, they

enter that state with all apparent promise of finally giving issue in form of perfect butterflies.

But that is the furthest progress ever made in such instances. Inside the small Ichneumon larvae having been merrily feasting meanwhile. They wisely keep to the fatty cellular matter — the reserve funS as it were — of the victim's organisation. Vital organs they do not touch, for so to do would be but for their own undoing. When the caterpillar sleeps away into fatal life, they give over feeding also and go into fuposhood themselves. By that time there is nothing left of the caterpillar except an empty skin, useless but for the fact that it serves as a shelter to its uninvited, merciless guests. By-and-bye they burst their pupsel swathings all right, and emerge into the light of day — a whole flock of Ichneumons, soon to be found busily pursuing (the females at least) caterpillar victimised of their own season.

Here, in Britain, nothing is more common towards the end of summer than to see the pupa of the white " cabbage butterfly " on garden walls, and alongside of it a whole colony of small golden cocoons also. These latter belong to the young Ichneumonidae which have fed their fill and just stepped outside to complete their metamorphosis in the open air. I have seen dozens of such groups within the space of a few yards upon high garden walk with a sunny exposure. In New Zealand I have not seen this, but others may havo done so. Collectors of butterflies and moths are often chagrined to find that' pupje, which they have fondly -treasured in' the expectation of seeing perfect .specimens p.merge therefrom, give issue to nothing but flocks of Ichneumon flies. — I am, etc., DINORNIS.

Edinburgh, February 16.