SAW-FLIES. in 



branches. If the injury stopped here, with the despoliation of his gooseberry- 

 bushes, the gardener might perhaps put up with it without much grumbling ; 

 but unfortunately the production of leaves and fruit are intimately connected, 

 and unless the branches are well clothed with the former, the crop of the 

 latter will be very small. If we search for the cause of this wholesale de- 

 struction, we shall find that it is occasioned by a multitude of small caterpillar- 

 like larvae, furnished with twenty feet, of a pale greenish colour, covered with 

 numerous rows of little black tubercles, each of which bears a small hair at 

 its summit : sometimes a thousand or more will inhabit a single bush^which is 



of course soon stripped of every green leaf; in about ten days these voracious 

 larvae have attained their full growth, they then descend into the ground 

 beneath the scene of their ravages, enclose themselves in a small cocoon, and 

 undergo their transformation into a pupa. In this condition they remain for 

 a fortnight, when they emerge in the perfect state. The fly thus produced is 

 a little saw-fly (Nematus grossularice), which in its turn becomes the parent 

 of another host of destructive gooseberry grubs. It deposits its eggs along the 

 course of the principal veins on the lower surface of the leaf, where they are 

 placed like rows of minute beads. The pupae proceeding from this second 

 brood pass the winter in the earth, and the perfect insects do not emerge from 

 them before the month of March in the following year. 



The Cuckoo-Flies (Ichneumon} are so called because they lay their eggs 

 in the interior of other insects, at whose expense their progeny are nourished. 

 For this purpose the females are provided with a boring apparatus, somewhat 

 resembling a long tail, called their ovipositor, by means of which they implant 

 their eggs in the backs of their victims, just as a gardener would set potatoes 

 in the ground. The female, when about to lay her eggs, may be seen flying 

 about with restless industry in search of the larvae or pupae of other insects, 

 or even spiders, to which she is about to intrust the support of her family. No 

 matter where they are hidden, under the bark of trees, or in cracks and crevices, 

 she is sure to find them out, and soon succeeds by means of her long ovipositor 

 in piercing their flesh, and depositing an egg in the interior of their bodies, 

 occasionally she repeats the operation several times. In a very short time 

 the eggs are hatched, and the larvae of the Ichneumon find abundant food in 

 their strange domicile. By this proceeding the hungry but sterile caterpillars 

 are prevented from changing into the prolific butterfly, and thus the world is 

 defended against their insatiable voracity. 



