List of the Insect Fauna of the County. 119
connected with their reproduction and whole life cycle were
first studied in this country by Newport and Huxley, and at
the present time M. J. Lichtenstein is so patiently and suc-
cessfully tracing some of the Aphides through their various
stages of development (which is so abnormal that he has had
to employ a peculiar nomenclature of his own to distinguish
the seven buddings or pseudo-births in certain genera) that I
am sure the members of the Club would welcome a resume
of his researches, but I can now only refer them to Mr.
Buckton's three beautiful volumes, recently published by the
Ray Society,41 and to Courchet's memoir42 before alluded to.
There are several species of Trioza, a genus of Psyllidae
(Homoptera), which cause swellings and rollings of leaves,
especially of several Composite ; but the only gall-making
species yet noted as British is T. Walkeri, Forst., whose larva
lives in the deformed leaves of buckthorn. The common
terminal globularly-swollen leaves of box, so well figured by
Reaumur, in which the larvae of Psylla Buxi live, can hardly
be called a gall.
Both the Coleoptera and Lepidoptera contain a few gall-
producing species. The common cabbage and other cruci-
ferous root-galls are familiar examples of the former, and the
knot-grass (Polygonum) pod-gall43 of Asychna aeratella, and
Laverna decorella, whose larvae produce swellings in the stems
of various species of Epilobium, are the only British exponents
of the latter. Further than their departure of habits from
other members of their groups, and their special bearing on
the various problems connected with gall-growth generally,
they afford no peculiar interest from our present point of
view, and they will doubtless receive more attention when the
coleopterous or lepidopterous fauna of our county is under
consideration.
41 'Monograph of the British Aphides,' by George Bowdler Buckton,
F.R.S., F.L.S., F.C.S., &c. London : Printed for the Ray Society. Vols.
i.—iii. (1876—1881).
42 "Etudes sur les galles causees par les Aphidiens" par L. Courchet
(Montpellier, 1879). Compare reference on p. 111.
43 'Entomologists' Weekly Intelligencer,' v. 81 (Dec. 11, 1858).