OF EPPING FOREST.
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Andricus albopunctata, A. malpighii, A. collaris and A. seminationis
are easily passed over. On the other hand, some galls, such as
Neuroterus baccarum and N. tricolor, being very difficult to preserve,
look so different in a collection compared with those growing
on the tree that previous examination of specimens in a collection
may be quite misleading to the beginner. When searching for
galls the casual examination of a branch is not sufficient; a minute
examination of buds, leaves, or cuttings, may often result in the
finding of several galls even when previous search has failed to
reveal their presence. So far as my experience goes, galls are
usually scarce in damp woods, and I have frequently found that
both species and specimens are more numerous in drier and more
exposed situations. One is often able to obtain better results in
a short time from searching hedges in a country lane than by
spending hours in searching trees in a wood.
Experimental Breeding.
In order to ascertain the life-history of the various
species of gall insects, and to investigate the gall forma-
tions in the different generations, it is necessary that very
close and accurate observations should be made. The act
of oviposition is a very important item in this respect. In
all cases it is best, and in many instances essential, that in
experimental breeding the natural surroundings should be
maintained, in order to obtain satisfactory results. For those
insects which lay their eggs in the buds, the latter should be
well developed; while for those which oviposit on the leaves there
should always be tender shoots ready for use. In order to effect
this a number of young oak saplings (about 4 or 5 years old)
should be obtained. They should then be planted in large pots
and placed in some sheltered position where they can obtain the
necessary amount of air and light and where they may be subjected
to the ordinary temperatures. At the same time the insects must
not be allowed to escape or get mixed up in any way. For this
purpose I have found the most satisfactory method to be one on
the same principle as that made use of, I think, by Dr. Adler.
A square box frame-work fitted with a glass top and having the
sides covered with gauze to give ready access to the air is placed
over each oak sapling. In some cases, in order to facilitate
observation, I had gauze on three sides only, the fourth side
being fitted with glass. In this way the insects are not allowed