MANGOLD AND BEET FLY. 
65 
Treatment of the foregoing kind will, I think, prove the best preven¬ 
tive. I have tried dusting of several kinds on the plant, but without 
perceiving any benefit; but a good drenching of paraffin and water I 
have known undoubted good results from. The difficulty is in apply¬ 
ing the latter, as the mixture requires constant and quick stirring 
during application, or the paraffin will come off by itself.” 
Mr. Jabez Turner, Norman Cross, Peterborough, also favoured me 
with the following note on autumn cultivation :—“ I am still in favour 
of autumn manuring for Mangold,—in fact, on strong land I do not 
think the land should be worked in the spring, except with a horse- 
lioe. This will in most cases give sufficient tilth, and the condition 
of the manured soil will force the plant beyond the attack of the 
Fly.” 
On the 17th of June Mr. D. Byrd, writing from Spurstow Hall, 
Tarporley, Cheshire, mentioned :—“ Our crops of Mangolds are very 
badly affected; we have not done anything to them this year, and 
the only manure used is farmyard manure of a richer quality than is 
usual.” 
A number of the Mangold leaves were enclosed for inspection with 
regard to minute objects found on the back of many in the field. 
These proved to be the white oval or spindle-shaped eggs of the 
Mangold Fly, with the reticulated surface, as shown in the figure. 
The eggs in many cases had hatched, and were mere empty films, 
the maggot having made its way into the substance of the leaf by 
boring a round hole into the skin, through which it had gone, drag¬ 
ging part of the egg-shell with it into its passage. 
Many of the leaves were already blistered by the maggots working 
within. On Nov. 8th Mr. Byrd mentioned “ that the same kind of 
eggs were to be found late in the summer under the largest leaves 
without causing any perceptible injury to the Mangold” ;* and further 
observed that, considering the very dry season, his root-crops were 
fully equal to those of former years, although he did not use guano or 
artificial manure to stimulate growth, but depended entirely on farm 
manure ; and remarked :—“ We feed our cattle liberally with cake and 
corn, which give rich manure ; and we also use dry soil to absorb the 
liquid manure, and fix the ammonia, making the whole more valuable.” 
The above note seems to me to point still in the same direction as 
the others, namely, that good cultivation and rich strong manuring, 
such as that noted, carries the crop through attack, but that, whether 
farm manure attracts the Fly or not, the attack is sometimes to be 
found badly where only farm manure is used. 
* This is in part because the old plants with large leafage suffer less from attack, 
and probably in part because the maggots are not able to bore through the skin of 
the leaf so readily as earlier in the year. 
F 
