THE COMMON GRASS CATERPILLAR.

Press, Volume LII, Issue 9173, 2 August 1895, Page 2

THE COMMON GRASS CATERPILLAR.

"Weekly Pie3s and Referee." By Ma.na.roa. DEPARTMENT 6f~"aGRICTJLTURE CALLED UPON. A. Terrible Pbst, Concerning Whico Information is Wantkd. Professor Kirk and the Agricultural Department have done good service to fa> rjaers and fruitgrowers in giving them useful knowledge about the numerous pests, both animal and vegetable, that have done so much harm to the producers of this colony. Could they not also bo induced to give ua some information concerning the common grass caterpi lar that for the last two j ears or more has done so much damage to the permanent turf Iβ many districts of New Zealand. This pest has perhaps done more lasting harm than is generally known, as its greatest ravages mostly take place far from the centres of population. In bush district?, the damage dona to turf on cleariuga laid down to grass ia often irreparable, for the grass is destroyed on land which cannot be broken up to be again laid down.

The caterpillar is about l£iu. long, in colour varying from alight-grey to almost black. Sometimes thie pest will sweep across a. settler* land in myriads, leaving the ground quite bare of grass, and then vanish. The grass will, in this case, spring again, and the. only damage done in that rubbish, which the caterpillars will not touch, has got a start and seeded the bare places ; and that the stock muet either be left to starve or be sold, often at a great eacriQce. But at other times this curee will return again and again, eating the grass right down and into the roots, killing much of it. Ryegrass, of which the caterpillars are fondest, soon succumbs ; cocksfoot will stand them longer ; white clover they do not touch. Poa Pratensis (smooth stalked meadow grass) seems to bathe only grass thnt cm suffer them with impunity. Anyone who lays down a turf in bush clearings without including these two last named is liable to caterpi lars.

The caterpillars are prob.ibly the eamo Rβ, or cioaely connected, with those that eat the cereal crop» of Canterbury. They have done very great damage in parts <>f the North Island and in the bush districts of Nelson and Murlborough. The imported birda will not look at them; even the starling seems to avoid the spote were they are numerous; and although near the bush the two robin 9, and near the sea the kingfishers do their best, what are they amongst so many? Pige, who have a larger capacity are, when available, their greatest enemy. The settler about to be partially or toUlly ruined, viewa their approach with dismay, but can do nothing to stay them amongst the stumps and logs by which (hey are protected. They invade hie house, go up stairs, and one man told the writer that he counted eighteen upon hia pillow one morning. In another case the caterpillars, after clearing all the grans and utterly destroying much, left the land to grow rubbish, and marching to the sea at low water, as if in search of other worlds to conquer, were drowned by the advancing tide; their bodies forming a distinct baud at high water for a considerable distance along the shore.

No one seems to know the life history of this alarming pest. Anyone who has learned the rudiments of natural history, of course knows they must be the larrae of some moth or butterfly, but which? The writer has had them confined in a glass case for over a month, where they eat several times their own weight of grass in a day; but they always died before getting to the chrysalis stage; probably they wanted the earth to bury themselves in.

• ThU devastating host is often accompanied in its march by an ichneumon fly in {treat numbers. The fly is like the common red one in size, colour and shape, except that it has beautiful blue-tinted wings which glitter brightly in the «un. Yet though this fly would naturally use -the paralysed body of the caterpillar in the ordinary way for depositing ite egge, no one seems to have seen it attacking, stinging or interfering in any way with it. The latter end of January and the month of February usually see the caterpillars arrive, whence no one seems to know, and they continue their ravages until the cold weather of approaching winter killa them or compels them to bury themselves.-They seldom attack old tuft* of cocksfoot, but luckily confine themselves mostly to pastures of that grass one or two year* old; but ryegrass is never safe; they will attack it and kill it out more effectively than ever the grub of the crauefly does on less areas.

What the sufferers from thi c orpillar would like to know is: What moth or butterfly is it the larva of t It is probably that of some night moth, for in one district where It abounds there is only one butterfly that U not rare, and the larva of this is a black hairy caterpillar, whilst the grass pest is smooth. But though, with the above exception, butterflies are rare, the night moths are numerous, especially a large whitish one with a very long body in proportion to ice winge. Will not the Agricultural Department obtain some information that would enable the settlers to recognise the parent moth ? They would then be warned by the advent in quantities of the latter that they may prepare for a visitation of the larvae and co be enabled to make timely arrangements as regards their stock. These they now often have to sacrifice in a hurry or keep, in hopes that the visitation will only be a slight one, until they are too low in condition to fetch anything but very poor prices, with the alternative of having to survive the winter upon a pasture eaten to the roots in the fall of the year.