SPOTTED CRANE FLY. 385 
Groningen. The precise definition of ‘‘ polder”’ is ‘‘ marshy ground”’ 
dried by cutting canals and ditches, and the description of the province 
of Groningen, in Johnston’s ‘ Dictionary of Geography,’ p. 583, is, 
‘Surface flat, low, and partly exposed to the inundations of the sea. 
It is rich in pasturage, but marshy in the §.E., where it is bounded by 
the morass of Bourtang.’’ If we add to the light and sandy arable 
land, the above low-lying marsh grass-land, and the upland pastures 
of the S. of Scotland, besides a sort of general ravage, such as feeding 
at the roots of Clover and Peas, eating off the crowns of Strawberries, 
and damage at roots of other kinds of garden and field crops too 
numerous to specify, it certainly appears that this pretty yellow black- 
spotted kind is hardly behind the common larger grey kind in its 
injurious powers. 
The remedies and means of prevention for both kinds are alike, 
and have already been given.* In these notes are given of methods 
of prevention of egg-laying, or of treatment of infested grass-land, 
including paring and burning (an excellent plan where it can be carried 
out at a paying cost), hand-picking, feeding stock on the ground, and 
cutting grass so that there should be no shelter for the flies, and the 
eggs and young grubs should be poisoned, and draining, as a matter of 
course, to put an end to the dampness and consequent coarse growth of 
sheltering herbage in which the flies delight; notes of stimulating appli- 
cations found serviceable to drive on good sound growth, and thus save 
moderately injured young corn or other crop, including in these nitrate 
of soda, which is doubly helpful by disagreeing with the grubs, as well 
as encouraging growth; notes of birds found to do good by clearing 
the grubs, and of mechanical measures useful in throwing them open 
to the birds, or of so firming the soil by rolling as to prevent the grubs 
travelling. These and many other points are given in detail, but 
amongst them all is one important habit of the grubs which appears 
much more certain now than in the earlier observations. This is the 
extent to which the grubs come up in the evening to feed on the surface of the 
ground, 
One of the first observations of the grubs coming in great numbers 
on the surface was sent me in 1880, by Mr. Whitton, from Coltness, 
Lanarkshire, N.B., where there was such a strong attack of 7’. oleracea 
larve that he noted he had never seen anything like it before for 
quantity. The grubs were noticed in moving plants in the garden, 
‘and as many as possible were killed with the spades; the beds were 
left for a day or two, and then forked over lightly again... . In the 
* See my ‘Annual Reports’ for the years 1879, 1880, 1884 (in which the subject 
of Tipule is entered on in much detail, pp. 19-28); 1892; and short mention in 
various other of my ‘Annual Reports,’ with figs. of the 7’. oleracea ; and in that for 
1879 of the 7’. maculosa also. 
D2 
