Memoi?'S of the Caledonian Horticidhiral Society. 197 



till the 26th of June, when all at once they ceased ; nor did 

 any that were in the pupa state in these pots ever come up 

 afterwards. 



" Suspecting that the great heat of the weather at this time 

 either killed them or delayed their coming up, I placed a pot 

 containing pupae (that had just gone down in the shade), in a 

 cool cellar, and at the usual period the flies came up. 



" I then took a number of pots (filled with earth), con- 

 taining pupae fully incrusted ; upon some of which I poured 

 boiling water; upon some unslacked lime, pounded to the 

 size of small peas, was put, and mixed with the earth 2 in. 

 deep ; others were allowed to remain as they were. Flies 

 from the last came up at the usual time ; but those that re- 

 ceived the lime or the hot water never produced flies. This 

 was repeated several times, and always with the same result. 



" In winter, therefore, when all these insects are in the 

 pupa state, I would advise cultivators to lift about 2 in. deep 

 from the surface of the soil in the gooseberry plots, then to 

 spread on hot lime, pounded, as before noticed, about three 

 times as thick as ordinary liming, and return the lifted soil 

 over the lime, keeping still the old surface uppermost, and 

 clapping the soil gently down with the back of the spade. 

 Great care must be taken that the lime is unslacked and 

 regularly spread, as it is merely the heat produced by slaching 

 that kills them. If the lime is too much for the soil, it may 

 be exchanged in the spring for soil from another plot. 



" When boiling hot water is used, it should be put on 

 when the soil is quite dry., and precisely in the same way as 

 the lime ; lifting the soil to the same depth, and returning it 

 in the same manner, as soon as the water is poured on. 



" In this way the pupae will be all above the hot water or 

 lime ; and thereby receive the full effect of the heat as it passes 

 upwards. 



" Where there is great space between the bushes, some lime 

 or water may be spared, by burying the surface soil at least 

 1 ft. deep, and tramping it firmly down in the bottom of the 

 trench : but near the bushes this cannot be done for the roots, 

 as the pupae frequently attach themselves to the under sides 

 of these ; and hence, though trenching down the surface soil 

 does destroy a part, it can never destroy the whole : and I 

 have even seen a fly come up when the pupa had been buried 

 8 in. deep, and the earth pressed down upon it. As to the 

 removal of the soil, it is quite useless, as the fly easily finds 

 its way back to the bushes. 



" As heat appeared to be the only agent fatal to these insects 

 in the pupa state, I next tried its effects upon them in the 



o 3 



