SAND DRIFT

Evening Post, Volume CXV, Issue 67, 21 March 1933, Page 9

SAND DRIFT

WAIKANAE PROTECTION

BEING UNDONE BY A GRUB

The attention of the Department of Agriculture has been called by Mr. W. H. Field, M.P., to the depredations of a caterpillar pest in destroying lupins planted as a sand-drift measure on the foreshore at Waikanae.

"As you are probably aware," writes Mr.: Field, "I have succeeded in recent years, by the judicious planting of marram grass (Ammophila aronaria) and tree lupin (Lupinus arboreus), in reclaiming some hundreds of acres of Waste, and much of it drifting, sandy land on about 2+ miles of the seacoast frontage at Waikanae. Much of this sandy land had been in the course of centuries reclaimed from the sea by the action of the native silvery sand grass (Spinifex hirsutus), but in recent times fires and stock have disturbed the surface and created moving saud,drifts, which occupied most of the area reclaimed by me. This was the condition of the land when I first acquired it about 35 years ago. Tho lupin had thriven wonderfully, and in the course of years enriched ' the soil by the humus formed by its fallen leaves and by the supply of nitrogen from its roots. The result was that prairie grass, cocksfoot, paspallum, and clovers grew abundantly among the lupin, the lupin plants affording warm shelter, and the land became my best winter cattle country.

"Last summer, about a year ago, however, I noticed that a number of the lupin plants had had their- loaves devoured by the-, larvae, a handsome greenish caterpillar, of a native moth known as Meeyna maorialis, and I feared that this grub might do serious damage to lupins this summer. My fears have proved well grounded, for the larvae during the past few. months have attacked1 the lupins in countless millions, many thousands of plants being already killed, and there is reason to fear that this valuable sandbinding plant is doomed to extinction. During the last day or two I learn that the pest has also attacked the beans in a vegetable garden at WaUcanae. It seems to confine its voracity'to leguininose (pod-bearing) plants only. The moth is ■ described in My. G. V. Hudson's .'Butterflies and Moths of New Zealand,''p. ISO, plates II and XXI. Its favourite food was the yellow kowhai (Sophora tetraptera), and it fed also on broom and other podbearers, but until recently it has not been a serious menace, and it was not generally distributed throughout the Dominion. Now, however, its spread has become, alarming. Unfortunately the caterpillar is protected by what are known as warning colours, which effectually prevent birds from feeding on it. Many larvae in tropical countries are protected in this way. It was in the habit of breeding twice a year, in November and March, but the caterpillars seem this year to have been equally numerous throughout the whole of the summer.

'I don't know that tho Agricultural Department can help in any way in checking this now pest, but I have thought it well to record the above facts for the Department's information."