152 INDIRECT BENEFITS DERIVED FROM INSECTS. 
means of defence, so far from thinking of escaping, frequently walk over 
the back of their enemy, and put themselves in his way. When disposed 
to feed, he fixes himself by his tail, and, being blind, gropes about on 
every side, as the Cyclops did for Ulysses and his companions, till he 
touches one, which he immediately transfixes with his trident, elevates 
into the air, that he may not be disturbed by its struggles, and soon de- 
vours. The havoc which these grubs make amongst the Aphides is asto- 
nishing. It was but last week that I observed the top of every young 
shoot of the currant-trees in my garden curled up by myriads of these 
insects. On examining them this day, not an individual remained; but 
beneath each leaf are three or four full-fed larvae of aphidivorous flies, 
surrounded with heaps of the skins of the slain, the trophies of their suc- 
cessful warfare ; and the young shoots, whose progress has been entirely 
checked by the abstraction of sap, are again expanding vigorously. 
~— But even these serviceable insects must yield the palm to the lady-bird 
or lady-cow (Coccinella), the favourite of our childhood, which, as well as 
most of its congeners, in the larva state, feeds entirely on Aphides'; and 
the havoc made amongst them may be conceived from the myriads upon 
myriads of these little interesting animals, which are often to be seen in 
years when the plant-louse abounds. In 1807 the shore at Brighton, and 
all the watering places on the south-coast, was literally covered with them, 
to the great surprise, and even alarm, of the inhabitants, who were igno- 
rant that their little visitors were emigrants from the neighbouring hop- 
grounds, where, in their larva state, each had slain his thousands and tens 
of thousands of the Aphis, which, under the name of the Fly, so fre- 
quently blasts the hopes of the hop-grower. It is fortunate that in most 
countries the children have taken these friendly Coccinella under their 
protection. In Prance they regard them as sacred to the Virgin, and call 
them Vaches a Dieu, Bétes de la Vierge, &c.; and with us, commisera- 
tion for the hard fate of a mother, whose “ house is on fire and children 
at home,” insures them kind treatment and liberty. Even the hop-growers 
are becoming sensible of their services, and, as | am informed, hire boys 
to prevent birds from destroying them. If we could but discover a mode 
of increasing these insects at will, we might not only, as Dr. Darwin has 
suggested, clear our hot-houses of Aphides by their means, but render our 
crops of hops much more certain than they now are. Even without this 
knowledge nothing is more easy, as I have experienced, than to clear a 
plant or small tree by placing upon it several larvae of Coccinella or of 
aphidivorous flies collected from less valuable vegetables. 
Lastly, to close this list of imparasitic insectivorous larvae, [ may mention 
those of Geoffroy’s genus Volucella, so remarkable for their radiated anus, 
which live in the nests of humble bees (V. bombylans), braving the fury of 
their stings and devouring their young; those of another species of the 
same genus (V, zonaria Meig.), which MM. de St. Fargeau and Serville 
have ascertained to live in wasps’ nests and destroy great numbers of their 
1 The larvae of some species of Coccinelle feed, according to Prof. D. Reich, solely 
on the leaves of plants; as that of C. hieroglyphica, which eats the leaves of common 
heath (rica vulgaris) after the manner of the larvm of Lepidoptera. Der Gesell- 
schaft naturf: Fy. in Berlin Mag. &c, iii. 294. The larva of Coccinella Argus, Seriba 
(0. 11-maculata Fab.), in like manner, Prof. Audouin found to feed on the leaves of 
the common Bryonia, (Westwood, Mod. Class. of Ins. i, 397.) 
