87 



by the close of the summer. There is considerable over- 

 lapping in the various broods, so that flies, eggs and larvae oi 

 all sizes may be found on the bushes at the same time. The 

 cocoons of the last brood of larvae remain in the soil during 

 the winter, and produce flies the following spring. 



^Gooseberry Sawfly caterpillars are sometimes confused 

 with those of the Magpie Moth, but it is easy to separate 

 them, since Magpie larvae are black a-nd white with some 

 yellow at the sides, and are, therefore, very different from 

 the speckled green sawfly caterpillars. 



In addition to the species here described, other species of 

 sawfly larvas are also found on gooseberries, but from the 

 growers' point of view it' is unnecessary to distinguish them. 



Natural Enemies. Several species of ichneumon fly have 

 been recorded as parasites on the caterpillars of the Goose- 

 berry Sawfly, but the latter do not appear to suffer from them 

 to an appreciable extent. As a whole, natural enemies do 

 not exercise a sufficient check on the sawfly, and artificial 

 measures of control are often necessary. 



Methods of Control. Attention is again drawn to the 

 advisability of dealing with small attacks. Otherwise it is 

 almost certain that serious trouble will follow. 



(1) Hand-picking is the simplest method in the case of a 

 few bushes, but it must be done before the colonies of young 

 larvae have scattered over the bush. Some prefer to pick the 

 leaves on which eggs have been laid. 



(2) Spraying is thoroughly effective against this pest; the 

 chief difficulty lies in the fact that the best washes are 

 poisonous. Lead arsenate may be used in the case of an 

 early attack where it can be applied before the gooseberries 

 have flowered, and also after the fruit has been gathered. 

 Hellebore, when fresh, and nicotine are also effective, and 

 though poisonous do not retain then: poisonous qualities for 

 long. They may therefore be used with safety if an interval 

 of three weeks be allowed between the dates of spraying and 

 picking. Pyrethrum, which must be fresh, may be tried where 

 a non-poisonous insecticide is needed, and there are also 

 certain proprietary insecticides now on the market which are 

 quite satisfactory and can be recommended for small gardens. 



(3) Formula : 



A. Lead arsenate paste .... ... Ib. 



Water ... 10 gallons. 



B. Hellebore powder 2 Ib. 



Water 10 gallons. 



C. Pyrethrum powder ... ... 2 Ib. 



Water ... .- ... ... 10 gallons. 



D; Nicotine 98-99 per cent. ... f oz. 



Soft soap *-l Ib. 



.Water ... ... ... ... 10 gallons. 



