STORM TROOPS AGAINST PESTS

Evening Post, Volume CXXVI, Issue 74, 24 September 1938, Page 28

STORM TROOPS AGAINST PESTS

.AH -over the world fanners and others are enrolling insects as their new allies in the fight against pests, says a writer in the "AdelaideChronicle." At the experimental station at Cheshunt,. Middlesex, millions of small wasps are now being bred for dispatch to many different countries, because they are the enemies of the white fly, principal curse of tomato growers. For a similar reason, wasps are regarded with such favour in Canada that Professor Morris, of the London Zoological and'Parasitilogical Institute, was recently commissioned to collect and purchase a large consignment' of , the black,. long-winged wasp of the Hungarian plains. It has been found that this wasp is the deadly enemy of the tsetse-fly, which, in certain areas of Canada, •was causing sleepy sickness; ':■*'*■[ , ' • The Hungarian village of Izsak was plagued with an unprecedented visita- ' tion! of these wasps, which threatened to deprive the villagers of their fruit harvest. To their amazement, the curse proved to be a blessing, for the Englishman, wanted thousands of wasps, and engaged sixty men, at a

cost of from £40 to £50 a week, to collect them! Vast numbers were caught and dispatched to Canada by air with a supply of their larvae. Canada is also breeding a small fly from Czechoslovakia to overcome the destructive sawfly, which is ravaging her forests. Locusts are at present .devastating Africa to the extent of £1,500,000 a year, but a recent entomological discovery offers hope that even this longstanding pest may soon be eradicated quite simply and cheaply. v It appears that there is a fly which deposits its eggs in the locust eggpocket immediately the locust has finished laying her eggs, and before the spume, with which she seals the egg-pocket, has had time to harden. The eggs of the fly hatch out and the maggots devour the locust eggs. At one time the great open spaces of Queensland bore little or no vegetation but the abhorred prickly-pear. Until this could be wiped out, agriculture was all but impossible. When all at-

tempts to destroy the shrub had failed, entomologists discovered a tiny catepillar, called Cactoblastis, whose favourite diet happened to be this prickly pear. Large numbers of this useful insect were obtained and turned loose upon Queensland's plains, with the result that the prickly pear has disappeared, and several hundred thousand acres of good land have been brought under cultivation. /

Not only insects, but reptiles, and even fish are now being pressed into man's service as "storm troops" against pests.

Emitting a clucking noise, like several barnyards full of hens, a large consignment of giant South American toads recently left London for Mauritius, forwarded by the Imperial Institue of Entomology.

More than eight inches high when fully grown, these toads are destined to form an expeditionary force against Phypalus smith, a sugar-cane parasite, which takes its name from that of a former Governor of Mauritius.

This particular consignment came from Porto Rico, where they were introduced to combat the menace of the same pest three years ago. Porto Rico, in fact, has established quite a thriving export business in this live insecticide, and batches of the toads have been sent to a number of sugarraising countries, including Hawaii. When • once it ; had been 4 discovered that malaria germs are carried by the anophele mosquito, the problem of stamping out this deadly disease resolved itself into a search for a means of eliminating this type of mosquito. A few years ago a little fish, about the size of a sardine, was discovered in the West Indies. These little fellows, Gambusia affinis by name, are extremely greedy, and : will attack smaller fish and any insects of grubs within their reach. But their special weakness is for the larva of the anophele

A consignment of these fish was brought to Papua when malaria was rife a few years ago, and introduced to every swamp and puddle within several miles of Port Moresby, with the result that the anophele mosquito, and with it malaria, has been almost eliminated from that part of the globe.