Hop Cultivation . 
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inch long, having red and yellow marks upon it. The other 
species are smaller. One has only two spots ; another has four. 
In hot, dry weather ladybirds appear in great quantities. Their 
little conical yellow eggs can be seen fastened in groups of from 
six to twelve on the under sides of the hop leaves. From these, 
tiny larvae emerge, and immediately begin to scour the plants 
for aphides. Ladybirds should be preserved, not only in hop- 
producing districts, but everywhere, as they feed indiscriminately 
upon all kinds of aphides infesting field and garden crops, and 
although they may be sometimes rather unpleasant in houses, 
where they frequently hibernate, they should not be killed. 
Housekeepers often sweep them — these betes il bon Dieu, as the 
French call them — from their winter retreats in the corners of 
sunny windows and behind window shutters, and other places, 
and, in barbarian ignorance, put them into the fire. 
There are two or three species of ichneumon flies which 
Fig. 9. — Syrphus pyrastri. Fly and 1 irva, magnified. 
destroy hop aphides by depositing eggs within their bodies at 
various stages of their life history, if aphides upon hop plants 
are examined, red spots can be often seen upon their backs. 
These are the larvae of ichneumon flies, in the act of consuming 
their hosts. 
Larvae of species of the Hemerobiidae (lace-wing flies), notably 
Clirysopa perla, nearly three-quarters of an inch long, ugly- 
looking, and so ferocious and rapacious that the French term 
them lions des pucerons, also destroy quantities of aphides, and 
must not be mistaken for enemies. 
Another friend of the hop planter is the greenish larva of the 
large, pretty dipterous fly known as Syrphus pyrastri (fig. 9). This 
larva is about three-fourths of an inch in length, with the ante- 
rior part of its body tapering to a point. Its mouth is provided 
with a three-pronged harpoon, by means of which it transfixes the 
aphides. After it has transfixed them, it flourishes them in the 
