NOTE ON BENEFICIAL INSECTS. 1 83 



wandering was impossible for them, and yet the arrangement 

 be such that any parasites on issuing might obtain their freedom. 

 Following such a plan, Decaux collected masses of unopened 

 apple buds spoiled by the grubs of the Apple Blossom Weevil 

 {Anthonomus pomorum), and instead of destroying these with 

 their contained grubs, he so arranged them that any parasites 

 could issue, with the result that 250,000 parasites escaped. 



The foregoing note is given because of work which is at 

 present in progress in connection with a parasite of Hylobius 

 abietis. Our foresters know well what an amount of destruction 

 this weevil can do in conifer nurseries. Two years ago, Mr 

 James Munro,^ while collecting in Aberdeenshire, found 

 parasitic grubs feeding on Hylobius larvas. The adults on 

 being bred out proved to be Braconids, similar to one which 

 the late Dr Nisbet had obtained in the West of Scotland. Mr 

 Munro has been working at these Braconids for some time 

 now, and experiments are at present in progress in the 

 laboratory and in the field. Apart from the scientific interest 

 attaching to the work, it is possible that the parasite may 

 experimentally be found useful in the war against Hylobius. 

 Too much must not be expected however, as the inquiry may 

 show that the Braconid parasite is already widely distributed 

 in Scotland. 



The Boards of Agriculture are interested in the inquiry, and 

 are encouraging and sympathetic towards the work. One of 

 the points of the inquiry is to determine the distribution of 

 the parasite, and in this work the members of our Society can 

 greatly help. Already we have records of the Braconid from 

 five counties. Even if it turns out that this parasite is generally 

 distributed, by breeding it in numbers in the field it may be 

 practicable to distribute it in a district where it is not known 

 to be present or abundant, and so reduce the numbers of 

 Hylobius abietis. 



' Cf. p. 144 of the present issue. 



