AN EMPIRE WAR

Evening Post, Volume CXII, Issue 8, 9 July 1931, Page 22

AN EMPIRE WAR

TINT STORM TKOOPS

WORK AT FARNHAM ROYAL

At Farnham House, Farnham Royal, in Buckinghamshire, I was shown round a garden full of weeds, and glasshouses in which the stems and twigs of plants were white with woolly aphis. And the men who havo carefully tended this garden for four years have reason to bo highly satisfied with their , work (says a writer in the "Evening News")----"Look," said my guide, indicating some twigs of an apple plant in ' one of the glasshouses. The white wool that had covered the plant had turned black on these twigs. "That's a result of our work," he said. For it is in this garden that the tiny armies are mobilised to go forth and fight our enemies of the insect world in distant parts of tho Empire. By Juno last year over 300,000 minute troops had gone to the perpetual war of pest and parasite. Farnham House Laboratory was founded in 1927 by the Imperial Bureau of Entomology, whose headquarters are the new wing of tho Natural History Museum at South Konsington. I had come down to Farnham Royal from the museum, but.before I left Major E. E. Austen, D.5.0., whose official title is "Keeper of Entomology," explained something of the work of the bureau. One is apt to think of museums d.s venerable places living in the dust of the past, but that is not at all Major Austen's view. "I believe," he told mc, "that a museum should move with the times; and when ordinary Londoners write to us on somo minor matter, asking, for instance, what steps they can take to rid their houses of earwigs or silver fish, I think it is our duty to advise them. Tho. museum was not meant for a reference library in that way, however. Our work is chiefly concerned in the matter of biological control, with the identification and classification of posts and parasites." , SAVING COCONUTS. Major Austen gave mo an instance of a successful campaign against a destructive pest in Fiji. A pretty little purple moth, which he called Leyuana Iridescens, was attacking the coconut palms there, and by 1925 it began to look as if in a few years there <would bo no coconut crop at all! ,-.,-j At last, in desperation, apprize of ; £5000 was offered ,to anybody who could find but how to get. rid of this pest. When the bureau heard about the trouble, three entomologists < went to Fiji, but for some time they could find no parasite to attack the coconut moth. At last, however, One of the scientists was sent to the Malay States to find out about tho parasites of a moth related to the Levuana—a very distant cousin. He found one, but it was being' preyed upon by a hyperparasite—a lesser flea, as it wero—and it was necessary to rid the parasite of this. • , ' . After threo generations had been carefully bred the thing was done. And it had to bo done completely, for if oven one hypor-parasito had bred later on, tho parasites' spread would have been much retarded. One female of a species with a threefold increase per generation, will have, in tho twentieth generation, about eight million descendants. - Now a fresh problem had. to bo faced: how to ship the mobilised army of parasites 4000 miles from Malay to Fiji? An entire hold of a Bhip was chartered and filled with littlo coconut palms infested with Levuana, which in turn were infested with the'parasites, 'which had been freed from their hyporOnly 315 insects survived the journey, but these were released over the islands. They wero enough. Pretty little destructive Levuana perished, and the coconut palms throve. THE PINES. In Farnham House itself the. rooms have been converted to laboratories and so forth. In one room my guide .showed mc a half-inch-long gelatine capsule with sawdust Ij. it. "There is the larva of a parasite of the wood wasp in there ready for a journey half round the world," ho said.. "The wood wasp is a very serious pest in Now Zealand, where its larva bores not only into f cUed logs, but into the living pine trees. "The New: Zealand Government asked us to investigate; and after_ a very long and difficult series of studies, and a lot of manual labour sawing up dozens of logs rand so , on, - two good parasites wero discovered. This one's name is Rhyssa persuasoria. Thousands of him have been shipped to New Zealand." In ono glasshouse, or insectary, as my guide called it, there were rosestocks that looked in very poor condition. "Here wo are rearing insects which attack blackberry plants—they are a pest to agriculture in New Zealand," he said, "ana the ragwort and St. John's wort we are cultivating in the garden are not meant to be orna-. mental; they are for breeding insects that attack them." HELPING- NEW ZEALAND. Some of the outhouses in this extraordinary garden contain refrigerators for keeping insects in a larval condition until the scientists are ready for them. Others contain incubators, for hatching out parasites. And in one I saw not only an incubator and a refrigerator, but also a clever arrangement for keeping insects in a summer condition. A thermostat kopt the temperature at summer heat by altering tho current through electric bulbs, and there was also a gadget which kept the air at the right humidity by heating a trough of water until vapour was given off. "One of our successes was the parasite of the leaf-cutting pear-midge," said my guide. "The littl<> brute wad accidentally introduced from Europe, where'it has plenty of enemies to keep it down, to New Zealand, where it had so few that it had a gay old time in all the pear-growing districts. "Modern rapid transport and coldstorago were probably responsible for them getting overseas; and aft a time the pears suffered so terribly that no satisfactory crops wore obtained for several years. "But the.consignments of parasitisod midge-infested material which we shipped out saved • the situation, and now tho crops are . satisfactory once again." _.