94 LEAFAGE CATERPILLARS. 
’ 
what are known as ‘‘sticky-banding,’’ may commonly be used with 
great success towards lessening amount of wingless moths making 
their way up the trees for egg-laying, as is shown by the numbers of 
moths caught during their attempted transit. But where, from any 
cause, these measures are only partially successful, or, again, infesta- 
tion occurs consequently on caterpillar presence from the egg-laying of 
moths which fly to the trees (instead of creeping up the stems), this 
(where we have access to the trees) may be got rid of cheaply and certainly 
by means of various washings and sprayings, of which I give details 
further on. 
But with regard to ravages of leafage caterpillars in the past, and 
to some degree the preceding seasons, as especially injurious to wood- 
land and forest Oak-leafage, there are some other important points to 
be considered. In the case of large areas thickly covered with timber 
trees, especially if (as I have experience of in some parts of the west 
of England) there is such a dense undergrowth of different kinds that 
it is necessary for paths to be cut to enable even the sportsmen to 
penetrate, it is a complete impossibility to carry out either preventive 
or remedial measures successfully ; even if it was possible to lay water 
on for washing down the grubs, or to cut passages for the spraying 
engines, the vast outlay would be without pecuniary return. 
But though at present there does not seem to be any artificial way 
in which we can cope with caterpillars as wood and forest pests, it 
seems to me to be quite open to reasonable hope that this exceptional 
amount of attack will lessen, when the month of May ceases to be, as 
it has been for at least two years, eaceptionally favourable (by reason of 
absence of ordinary amount of rainfall) to existence of caterpillars and 
insect development. 
If we turn, firstly, to the reports of droughts in Symons’s ‘ British 
Rainfall for 1895,’ * we find that, compared with the average from 
1888 to 1894, 1895 had nearly forty per cent. more than the average 
number both of ‘‘absolute’’ and ‘partial’ droughts.t ‘If we break 
the eight year period into two of four years each, we shall find that 
droughts in the last four years have been nearly twice as severe as in 
the previous four years. Turning now to the tables themselves. . 
We have the ‘partial’ drought in May and June, and, lastly, the 
‘absolute’ drought, chiefly in the south of England, of between two 
and three weeks, during the hot weather in the latter part of 
* «British Rainfall, 1895,’ by G. J. Symons, F.R.S., and H. Sowerby Wallis. 
Edw. Stanford, Cockspur Street, S.W. 
+ Technically an absolute drought is a period of more than fourteen consecutive 
days absolutely without measurable rainfall. A partial drought is a period of more 
than twenty-eight consecutive days, the aggregate rainfall of which does not exceed 
one-hundredth of an inch per diem.—(See ‘ British Rainfall for 1895,’ p. 130.) 
