Description

Insects have always been the bane of agriculture.To this day they destroy millions of tons of vegetables and fruit, cereals, and timber. We pay them the terrific toll of a quarter of the overall harvest. And in earlier times their share was even bigger because man had no etfective means of fightingf the six-legged pests.To learn to flght the insects man first had to study them.The Russian Entomological Society was founded in St. Petersburg in 1860. Arnong its members were all prominent entomologisis of the time. The principal task the Society set itself was finding ways and means of combating harmful insects. A special commission was formed within the society for this express purpose.It decided to begin by drawing a Iist of harmful insecis. A large group of entomologist undertook the task,and it was believed they would cope with it easily enough.Yet years went by and the list was still incomplete.The thing was that on top of the mammoth work involved in studying reams of entomological literature(altogether the commission perused more than 10,000 works in Russian and foreign languages) and in making a detailed study of every insect, each year brought new discoveries and additions to the list.The work on the list look seventy years,and it was not published until 1932, when with included 3,124 species.But no sooner had the list been published, than additions and amendments begin to be introduced into it; even while it was being printed several new pests were discovered.More than forty years have passed since.Many more insects have been included in the list.And still it cannot be considered complete, for each new day brings new discoveries! Carl Linnaeus described a mear thousand and half insects.By the middle of the nineteenth century entomologists knew 48 thousand insects, and by the end of the century the figure had grown to half a million species. Today it approaches a million.And yet entomologists hold that another million or even a million and a half species of insects dwell on this earth of ours and have still not been described.And it may very well be that the boldest forcasts will prove erroneous,as it happened to the forecast made by the famous German naturalist Lorenz Oken.In the thirties of last century, when science knew some 30 thousand species of insects,Oken conjectured that their total number should be twice as large (that is some 60 thousand). Many of his colleagues regarded this conjecture as too bold, especially since great Cuvier had announced that everything had been discovered on our planet. But a mere hundred years later the number of butterflies alone reached 80 thousand. Within the next ten years another 10 thousand were added to the list (the average of a thousand species a year).Here is yet another example. In 1935, 18 thousand species of woodcutter beetles were known. And ten years later the list grew by another five thousand. To be sure, an insect can hide even inside a human dwelling so that you will never find it, and in the forest the task of finding it becomes more formidable still.You may not see it at all,and if you do,you may not take notice of it,and even if you do you may fail to realise it is a new species.That is one of the reasons why our information about insects is much less complete than about all other animals and why discoveries are still being made in in entomology in far greater numbers than, for instance, in ornithology or mammalogy.