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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The diseased plants or leaves should be removed and burned, and 

 the remainder of the plants sprayed either with freshly-made Bordeaux 

 mixture or with a solution of potassium sulphide (1 oz. to 3 gallons of 

 water), repeating the spraying after an interval of about a fortnight or 

 three weeks, and again if necessary. Where the disease has existed in 

 a previous year it would be well to commence the spraying early in the 

 season, whether the disease makes its appearance or not, as a safe- 

 guard. 



The disease is usually noticed rather late in the season when it has 

 attained proportions too great for any hope of checking it to be justified, 

 but it seems as a rule to make its appearance somewhat late in the 

 growth of the plants. We have, however, had specimens sent us as 

 early as July. 



XI. — A Note on the Habits of the Narcissus Fly. 



By F. J. Chittenden, F.L.S. 



In this Journal, vols. xxvi. (1901), p. 249 and xxvii. (1902), p. 181, 

 the Eev. W\ Wilks gave a summary of all that was known up to that 

 time concerning the life-history and habits of the narcissus fly [Merodon 

 equestris F.), together with a number of fresh observations. In 1910 

 this insect was scheduled by the Board of Agriculture under the powers 

 conferred upon them by the Diseases and Pests Act (see Journal 

 E.H.S. xxxvi. p. 153), and those in whose garden it is found are 

 bound, under a penalty, to report its occurrence to the Board, while 

 certain countries have prohibited the importation of narcissus bulbs 

 unless they are certified to be free from the narcissus fly or to have 

 come from a garden where the fly is unknown. 



Up to the time Mr. Wilks wrote the article referred to above, it was 

 believed that the narcissus fly confined its attacks to bulbs of narcissus, 

 and we have failed to find any reference to an attack upon any other 

 plant. Facts have come to our notice, however, during the past winter, 

 that are of some economic importance, for they show that the fly does 

 not restrict its attacks to the narcissus. 



In November 1910, a bulb of Hahrafithus pratensis, which had lain 

 some time unplanted, was sent to us. The bulb had been imported from 

 Holland. On examination it was found to be almost entirely eaten 

 away inside, and had the usual tunnel opening below, while it contained 

 a grub which we believed to be that of Merodon equestris almost full 

 grown. The next post brought from another source a bulb of Vallota 

 purpurea containing two precisely similar grubs. The latter w^as one 

 of a number of Vallota and EucJiaris bulbs which had been sent 

 in May 1909 from Sierra Leone. Most of them when potted up grew 

 well, but some failed to develop but weakly. Examination showed 

 the presence of one or more grubs in each, and the characteristic hol- 

 lowing out of the bulb by the grub. 



The bulbs were potted up into separate pots, covered with muslin to 



