INSECT ENEMIES

Evening Star, Issue 22560, 30 January 1937, Page 3

INSECT ENEMIES

MANKIND’S FIGHT TOO FEW EXPERTS While many millions of pounds’ worth of damage is done to agriculture every year through the ravages of insects, there are only seven or eight entomologists in the world who are able to identify the parasites which in turn prey on- the insects, says a writer in the ‘ Daily Mail.’ “ It is not that the men to do the work are not available,” Sir Guy Marshall, director of the Imperial Institute of Entomology, said. “ There are in fact, able men who could be trained, but Governments will not put down the money, apparently because they do not realise the enormous extent of the damage. “In this country, in spite of the good work that is being done, the loss to crops through the ravages of pests amounts to about 10 per cent., but in the tropics the loss is about double. So far as this country, the dominions, and colonies are concerned, the damage amounts to many millions of pounds each year.” Sir Guy Marshall added that there was a general shortage of entomologists, both of those who worked in the field finding the injurious pests, and of those, termed “ scientific entomologists,” who identify the creatures and their parasites. “ Almost every insect has what is called a parasitic wasp attendant on it,” said Sir Guy, "and, through the scarcity of entomologists, there are hundreds of such parasites awaiting identification. That means, of course, that a big handicap is placed on the work of fighting pests by introducing to them their natural enemies.

“ One important aspect of the problem is that a creature which may be a serious pest in one country may be practically harmless in another. The study of it in the latter case may lead us to jh-e discovery of the natural

enemy which is keeping it under control. , . “An interesting instance of this is afforded by the saw-fly, which strips the leaves of the spruce tree in Canada. This creature is kept under control on the Continent by its parasitic wasp, and now we are introducing a big supply of these parasitic wasps into Canada in the hope that the ravages will be reduced to a minimum.^ “It is very important to identify the parasites, for some, called hyperparasites, are parasitic on another, and are, therefore, as harmful as the injurious insects themselves. “ The concentrated attention of science on such problems is needed so that the feeding of millions upon millions of insects on materials which we need for our own use may be stopped. “I do not say that we could obviate all the damage that is being done, but we could very greatly reduce it. The expenditure would be well justified.’■