126 
THE WEEKLY ENTOMOLOGIST. 
opposed to the idea of Immigration. 
Mr. Gregson’s assumptions that 
Butterflies “ do but want flowers,” 
and that, having found them on 
Dover Cliffs, they would fly no 
further, can scarcely be maintained. 
If flowers were all they wanted, these 
they had in plenty, and needed not 
to cross to our coast to find them. 
The Indian Cardui had as many 
flowers in the locality they were fly- 
ing from as in that they were flying 
to. * I think Butterflies and Moths 
have many little tastes and peculiari- 
ties, we are unacquainted with. 
I may observe, however, that Mr. 
Curtis more than once expressed to 
me his conviction that many of the 
“ Disputed ” British species, were 
British, — including even Chryseu. 
He instanced Antiopa and Dispar, 
once well known to be plentiful, — 
now all but extinct, and asked, — “if 
these, why not others ? ” 
I shall be glad if others, better 
informed than myself, will pursue 
the subject. One who wishes to be 
an Entomologist. 
Extirpation of Insects. — Our friend 
the Rev. Jos. Greene, at page 77 of 
the ‘ Weekly Entomologist,’ seems to 
wish this question discussed, and, as 
I believe the question was opened in 
consequence of a few remarks of 
mine, I feel compelled to give a little 
of my experience in reply to what 
has been ali’eady said upon the sub- 
ject. I shall confine myself to as 
limited a space as possible, and if I 
differ from the conclusions arrived at 
by others, I hope we shall not disagree. 
For my part I cannot admit that 
Nematus ventricosus or Pieris Bras- 
sica have ever been pursued system- 
atically over a whole district. The 
gooseberry grub being still a pest, 
is no proof whatever that the hand of 
man cannot, or does not effectually 
lessen or extirpate species ; — first, 
because the hand of man is only par- 
tially and temporarily applied. Thus, 
I pick, or cause to be picked every 
leaf from my gooseberry plants, just 
as the young larva? show that they 
have begun to feed, in the garden 
newly entered on by me, and by 
attending to my trees for an hour or 
so daily, for a week, I guarantee 
myself from the attacks of this insect. 
Most assuredly, if I effectually crush, 
or otherwise destroy, the eggs and 
youflg larvae so picked, I extirpate 
that brood, but my neighbour cares 
nothing about the matter. He 
grumbles, and lets the grubs devour 
the foliage of his plants, next 
door to me, and, next brood, I, who 
have been free for the whole of May, 
find fresh examples on my trees in 
June, and again, a third batch of 
young larvae are eating away in my 
garden, before the end of the summer, 
whatever may have been my care, 
simply because other people have 
been breeding stock, while I have 
been trying to extirpate mine. Ac- 
cording to the new 4 Immigration ’ 
theory, insects will go to unpopulated 
districts. This argument applies 
equally to P. Brassicm, and it struck 
me as quite unworthy of Sir. New- 
