WAR AGAINST PESTS.

Ashburton Guardian, Volume 59, Issue 224, 5 July 1939, Page 7

WAR AGAINST PESTS.

COMBATING ENEMIES OF CROPS.

Pests, principally insects, are csti-„ mated to destroy every* year something like one-tenth of the world’s crops. To eliminate these pests almost every country in the world spends large sums of money in research and in direct assai.lt, '

The British Empire Marketing Board laid the foundation of the broader treatment of pest control by sending out parasitic insects to fight the white butterfly pests of New Zealand and others.

House sparrows taken in 1860 from Liverpool to New York and released, and afterward introduced into Boston, Philadelphia, Halifax and Quebec have increased till now they swarm from the Pacific to the Atlantic seaboard of the whole of North America as one of the major bird problems of American agriculture. Starlings introduced to New York 60 years ago are also increasing with ominous results.

The danger of transporting insect* accidentally from one country to another. is much more serious.

The Colorado beetle, which first appeared in Europe in 1877, caused £l,000,000 loss hy ruining 2,510,000 cwt of potatoes of the French export industry in 1929 and is now a serious danger to English, Irish and German potato growing centres. The moth Ephestia flutella, which first damaged. cured tobacco in Russia in 1915, caused £IOO,OOO damage to British tobacco warehouses alone, in 1929-30.

British inshore and estuary fisheries, as well as public health, are endangered by the mitten, or woolly-cdawed crab of China which was accidentally brought to Germany in the River Aller, in 1912. Over 700,000 of- these crabs were caught at Hamburg in 1931. They are destructive to fish food. The Argentine ant, the American chrysanthemum midge, cockroaches,, the Alexandrine rat, and the Indian tree rat are all migrated pests which are a danger to the food and health of Britain.

In addition to the financial losses caused, the occurrence of pest outbreaks lias marked effects on the financial market. The sudden appearance of swarms of grasshoppers in the United States wheat fields during the 1933 bumper crop period seriously affected prices on the stock exchanges, and the Chicago wheat pit—so much so that investments in view of insect pests was a new gamble to be introduced. The loss caused by insects and mould (many moulds or fungi, specially those destroying timber, arc transported by insect posts) to good quality raw cocoa during storage has been estimated at 40s a. hundredweight during two months storage. The losses to the dried fruit industry amount to thousands of pounds, and in one section of the British Empire exceeds £15,000 a year. Even Japan has its foreign insect pest-troubles; the American pea-weevil which appeared there in 1900 was, in 10 years, distributed all over the country ; the European bean-weevil which reached New Jersey, U.S.A., in 1870, is now becoming a serious danger to Japan's annual crop of broad beans. The pest was probably introduced to Japan by American trading. The introduction of ornamental goldfish to waters in* Malay, has added alien pests to that country. The same applies to the dreaded prickly pear in Queensland.