GREEN FLY.

New Zealand Graphic, Volume XLI, Issue 19, 4 November 1908, Page 41

GREEN FLY.

Of these tiny insect pests so well known and well detested by the gardener a writer of the “Daily Telegraph” observes that they reproduce theinselv<-s —that is to say. propagate —with as founding rapidity. The great Linnaeus, a hundred and fifty years ago, came to the conclusion, from liis obsermtion of one kind or species, that in one year a single aphis would produce a quintillion of descendants. Without insisting upon the exact numbers in different kind's of aphides, we may s:i-y that that' is a fair indication of the rate al which they produce young. No sooner does a mother aphis produce some thirty or forty young, than in a few hours or days, ae cording to the warmth of the season nil the abundance of food, these young liave grown to full size and themselves each produec the same number of young, and so on through the summer, and even lotto the autumn. Nineteen rapidly following generations have been conntml tn some kinds of the plant lice. Hence it is no wonder that these little creatures increase exceedingly and cover the leaves and shoots on which they feed: no won dor that they furnish a plentiful nourishment for the ladybirds which prey on

them. But the most curious thing is this, that these abundant and rwpidlyTeprodueing broods of aphis are all females, and that they do not lay egg-, but extrude their young in a more or Jess complete state of development, that is to say they are viviparous. They are all females! It is only late in'the season that males are produced.