4 
known, we need many more observations, both carefully 
made and carefully recorded in full details; and still 
more, we need considerations as to how, though we 
cannot alter the weather, we may modify its effects. 
At present weather-influence is commonly spoken of 
as if the weather—that is, cold or heat, drought or 
rainfall—acted in just the same way on all kinds of 
insects, and also on insects in all their different stages 
of life, whereas this is very far from being the case. The 
Golden Chafer, or the Turnip Flea-beetle, thrive in hot 
summer sunshine, whilst the Daddy Longlegs or Crane 
Fly likes the cool dampness of overshadowed meadow 
grass; and again, what one species of insect thrives on 
in its fully-developed state may be precisely what would 
not have suited it as a caterpillar or grub. 
Also we need to distinguish more exactly what is 
meant by the word “weather,” for difference in amount 
of heat or cold act very differently, according to the 
amount of rainfall or of moisture accompanying them. 
Many grubs, such as are called “ surface caterpillars,” 
will stand severe cold as long as they are in their own 
specially-constructed wintering places, but if thrown 
out, so that they are exposed to wet also, they die. A 
sudden downfall of cold rain will clear off caterpillars in 
summer ; or again, with regard to some kinds of eggs, 
though heavy rain may destroy them, yet they will not 
hatch as well in heat and drought as when there is 
a certain amount of moisture in the air. 
Insect-life is also affected, not only by the state of the 
weather at the time being, or shortly before any given 
time, but the effects of weather may be traced for one or 
for two years or more, sometimes directly in the con¬ 
ditions of the insects themselves, sometimes by pro¬ 
moting the growth of special weeds (Charlock for 
example) which may be the food-plants of some special 
crop pest, and also by so affecting the state of the 
ground that regular measures of cultivation, by which 
pdant and insect vermin are usually cleared out, cannot 
be carried on. 
