HOP-FLY. 
79 
For a favourite plant infested witli blight there are seve- 
ral remedies, — smoke of tobacco, snuff, &c., but the most 
effectual, and the least hurtful to the plant, is to let it 
been slightly altered in order to accommodate it to that of the hop-fly. 
" A fourth enemy to the hop-fly is a minute ichneumon, similar to that 
which is parasitical on the blight of the rose: the males of these ichneumons 
are active, flying about, and coursing over the leaves ; but the female is of less 
roving habits, and will generally be found busy in providing for the establish- 
ment of her numerous progeny : placed, at her birth, among myriads of hop- 
flies, she has no dwelling to construct with artful industry, nor stores of food to 
collect by distant rovings. With extended antennae, and wings shivering with 
desire, she paces leisurely amongst the defenceless herd; and as soon as she 
has selected one by a light touch of her antennae, she stops short at about her 
own length from it, and rising on stiff*ened legs, bends her body under her 
breast till the end of it projects beyond her mouth ; then, erecting her back by 
depressing the hinder part, she simultaneously makes a lunge forward with the 
body, which is then extraordinarily lengthened, and, by a momentary touch, 
deposits an egg on the under side of the hop-fly, near its tail. The hop-fly 
will sometimes kick and sprawl, so as to discompose the ichneumon ; but being- 
anchored by its sucker plunged in the bark, can make no effectual attempt to 
elude the deadly weapon : should it, however, be wandering at large, and free 
to struggle, she shows great activity, by traversing round it in the attitude of 
attack, till she can take it in flank. The delicate sense of the antennae seems 
to warn her where a germ has been already deposited, as she will pass by those 
which have been stung some days before; and there is never found more than 
a single grub in each individual : when all the interior of the hop-fly is con- 
sumed by the grub of the ichneumon, it will be found separate from its fellows, 
and motionless, usually on the upper side of the leaf, to which it is glued by 
some viscid exudation. The hop-fly now appears distended, and of an opaque 
hazel or lighter tint; if opened, the full-fed grub of the ichneumon will be 
discovered doubled up and filling the cavity, its head being next the tail of the 
hop-fly; in a short time the parts of the perfect insect are developed in a qui- 
escent state, and in the same position, the integuments of the grub being 
doubled up below it in black grains : it spins no cocoon, being adequately pro- 
tected by the indurated skin of its victim. A few days are sufficient to give 
consistence to its parts ; and while the new-risen sun is yet glistening in the 
early dews, the winged insect, by a push of its head, detaches the latter rings 
of its case, which separate in the form of a circular lid, often springing back to 
close the orifice after the inhabitant has gone forth, born in the maturity of her 
energies and instincts to renew the circle of existence." 
