13 AUGUST 1927, Page 12


Another traveller's tale. Visitors to Switzerland, especially the Engadine, come upon wide areas of larch forest that look dead and brown instead of a lively green. The change is due to the ministrations of the green tortrix, a silk-spinning caterpillar that kills the larch, not so much by sucking its juices as by faggoting the needles, especially at the end of the shoots, by tight bands of its silken bonds. It uses the silk to swing itself from twig to twig and also, like our " tent " caterpillars, in a more domestic reference, for shelter and for nurseries. The numbers are unbelievable and the damage serious. Only one remedy is of any avail. The proper enemy of the caterpillar is the small bird ; and the Swiss, who in the past have not been very kind to small birds, are now setting up numerous shelters and canteens that the small birds may be able to endure the hard winter and get to work in the spring on this larch-throttling tortrix. It is always pleasant to have one more instance of the equilibrium of nature in a country where bird protection prevails. Inciden- tally it has astonished me in Switzerland to find jenny wrens greatly flourishing above the snow line.