WHEAT-BULB FLY. 
41 
I believe, to have this on fallow; and also in the patches of Swede 
and Turnip-fields where the crop has failed; and very likely indeed 
where Potatoes have been cleared early, or before they were ripe. How 
far the Swedes or Turnips would have been grassy amongst the crop 
cannot be known without definite report. 
The attack does not seem to be connected with the Turnips them¬ 
selves, as we have two instances (see my 12th Report, p. 85) of the 
infestation occurring very badly on land which had been prepared for 
Turnips, but not sown with them, owing to drought. 
We cannot make sure, without further observations and examination 
of specimens, how the case may be, but it would explain all the 
peculiarities of the observations, and agree with what was to be 
expected to fill in the history of the attack, if it was found in summer 
or autumn in young Couch-grass, or other wild grasses, on so-called 
bare land. This would give the link between the appearance of the 
Flies in July and the subsequent attack. It is against all likelihood 
that the identical flies which appear in July should live on to lay their 
eggs from October to March, but very likely that they should lay them 
on wild grasses during July, or at least shortly after they appeared; 
and the maggots from these eggs turning in regular course to chrysalids 
where they fed would give precisely the missing link that we need to 
complete the year’s observations. They would be where the infested 
grasses on fallows, or on bare patches, &c., had grown. This would 
account even for the portions being sometimes so observably marked 
in area; and I think the following observation, sent me in 1886 by 
Major Salmon, of Tockington Manor, Almondsbury, Gloucester, bears 
on this view of the subject:—“ It is also to be remarked that the tops 
of the ridges ( i . e., where the soil is the liollowest, from the plough 
having thrown up the two ridges together from opposite directions) are 
more affected than the ridges below these or in the bottom.” In this 
case the hollowness would be more favourable for escape of the flies 
from the chrysalis than the solidly laid earth. 
If in the coming season we could have observations in infested 
districts as to whether young wild grass-plants or side-shoots are seen 
going off on fallow, or otherwise bare land, in the same way that Corn- 
plants are destroyed by the Wheat-bulb Maggot, we might lay our 
hand on the reason of infestation being continued, notably from the 
above conditions, and gain a clue towards checking this somewhat 
serious attack. 
