- The willow trees of East Anglia and the larch
trees of Switzer- land have both suggested. an appearance of winter to travellers and reporters. Each variety of tree has its particular enemy, though some caterpillars have a considerably catholic taste. The grub of the white ermine moth is devoted to the willow as two species, one bright green and the others nearly black, restrict themselves to conifers in- and about Switzerland. It was suggested in one report that a new enemy had been found on some nettles. If an enemy which devoted itself to nettles could be found it would be welcome enough ; but the nettle is the favourite host plant of the very loveliest of our autumnal butterflies ; and it is a general rule (though it is contradicted by some of the scaremongers) that no butterfly in any of its forms is hostile to plant life. The common cabbage butterfly is pretty well the only exception. The oak is the host of more insects than any other plant, and several of them are harmful ; but even when the flies breed on every other leaf or the green grub of the small oak-living moth strips the trees bare, the oaks recover, and sometimes put out new leaves late in the
autumn.
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