COLORADO BEETLE

New Zealand Herald, Volume LXXI, Issue 21716, 3 February 1934, Page 8 (Supplement)

COLORADO BEETLE

A DESTRUCTIVE PEST The potato beetle (Lcptinotarsa decern lineata) is one of the most serious pests of potatoes. The beetles feed on the plants, but the greatest injury is caused by the feeding of the grubs, which can clear a patch of potatoes of all foliage and most of the stems in a very short time. This pest is also well known as the Colorado beetle. It was originally a native of the Rocky Mountains, and then fed on weeds belonging to the potato family. When potatoes were planted the beetle turned its attention to this crop and it has since been a pest of the first order. Its spread has been rapid, and now it is present throughout the United States and a large part of Canada. It

has also reached France where is appears to have established itself. Several times the beetle has reached Germany, but on each occasion it has been eradicated. Shipping is the common medium of spread, the beetles arriving in consignments of agricultural produce from infected areas. In 1901 the pest was found at Tilbury, in England, but it was destroyed. In 1933 a second centre of infection appeared, also at Tilbury, and within the last few weeks other beetles have been found in the same area. It is essential that Colorado beetle be prevented from establishing itself in this country. Were it to do so, it would be necessary for potatoes to be sprayed with an arsenate of lead spray several times in a season, which would add greatly to the cost of production. It is therefore of extreme importance that any beetles resembling the Colorado beetle be immediately sent, securely packed, to the nearest representative of the Department of Agriculture. The beetle is about Jin. in length, is bright red in colour, and has 10 black stripes on the back. The rest of the body, and the head also, bear black spots. The grubs are bright reddishyellow in colour with a number of black spots and rings on the sides. The fullyfed grubs turn into yellow pupae in the soil, remaining in that condition from 10 to 15 days. They then emerge as beetles. The beetles of the last generation descend into the soil to a depth of from lOin. to 12in., where thev spend the winter, appearing again in spring to lay clusters of small yellowish eggs on the potato leaves. RASPBERRIES IN AUTUMN When well-grown, autumn-fruiting raspberries provide a welcome addition to the dessert of April and May, varieties which naturally bear fruit late in the season on canes of the current season's growth should bo chosen. The site for autumn-fruiting raspberries must be in an open, sunny part of the garden, sheltered from high winds. When planted in a shady, over-grown corner, the fruits will not receive sufficient sun to ripen properly. If grown beneath the drip of overhanging trees, the bulk of the fruit will rot on the canes before reaching maturity. The canes should be planted in wellprepared ground in early autumn. The first pruning consists of cutting the canes to within Ift. of the ground in late winter, but the pruning in subsequent years is altogether different. When the row is established, the only pruning required is to cut every cane I down to the ground in August. On the young canes, which grow in spring and summer, fruit will be borne in the autumn. In late spring and summer, the new growths from the base must be regulated and thinned. Some six to eight canes should be left to each clump, the surplus being cut away. The canes left should be well supported, as the fruit is borne near the tops of the canes and not along their entire length, as in the case of the summer-fruiting varieties. The best autumn-fruiting varieties of raspberries are Hailsham, sometimes known as Hailsham berry, November Abundance, with sweet medium-sized berries, and Queen Alexandra, which gives good quality fruit. Hailsham is probably the best all-round variety, but Lloyd George is also good. Frequently when this latter variety is grown as a summer-fruiting variety, it persists in producing a certain amount of late berries on the tops of young canes. Lloyd George, in fact, is a perpetualfruiting raspberry. The habit of carrying two crops in a season is not to be encouraged, and the variety should be grown either for summer fruit, or for autumn, and treated accordingly.