94
THE LEPIDOPTERA OF ESSEX.
soon as favourable conditions again obtain, but when there is no
neighbouring wood, the balance may never be restored. In very
hot seasons local butterflies become to some extent migratory ; such
was the case with L. sibylla last July, and I should not be surprised
if, this year, specimens are met with in woods where none have been
previously seen. Mr. Laver saw a specimen in the town here [Col-
chester] last year [1881] two miles from any known locality" (Har-
wood ; Proc. E.F.C. iii. xxvii).
Captured by Mr. Morton, in Essex, not far from the town of
Tollesbury, and brought to me on July 11th, 1695 (Ray ; H.I. 127).
Hartley Wood [St. Osyth] (Jermyn ; V.M. 69). Woods between
Walton-on-Naze and Brightlingsea, "but seems to be gradually dis-
appearing" (A. Lambert and J. W. Douglas ; Ent. i. 384). St.
Osyth, July, 1845 (Douglas ; Z. iii. 1089). St. Osyth (Harwood;
B.B. 70). Common, woods bordering road from Colchester to
Ipswich, July, 1836 (ex E. Doubleday ; Ent. Mag. iv. 231). Not
rare, Colchester, 1867 (Harwood ; E.M.M. iv. 162). Colchester
(S.M. i. 34). History of hibernation discovered by Dr. Maclean of
Colchester (Newman ; Z. xix. 7565). Great Bromley (E. Alston;
E.W.I. ii. 143). One, near Park Hall, Epping, 1836 (A. E. Double-
day ; Ent. Mag. iv. 231). Epping (S.M. i. 34). Saffron Walden
(Jeffrey ; B.B. 70). One, Debden How Wood (Joseph Clarke).
The dark variety figured in Newman's B.B. 67 has occurred in
Essex (S. Stevens ; Proc. E.S.L. Sept. 5th, 1853, 127) at Colchester
(W. T. Bree ; M.N.H. v. 667). Mr. Ingall also possesses a similar
specimen from the same neighbourhood (Westwood and Humphreys ;
B.B. 61.)
Apatura iris, L. Purple Emperor.
Geographical Distribution—Central and South-west Europe, rare in Asia Minor,
China (doubtful), England, south of Humber.
Larva—Green with yellowish spots, yellow or pinkish stripes at sides in front
and oblique yellow stripes in middle ; horns bluish-green in front with brownish-
red tips. Food—Sallow, aspen, poplar. Imago—June and July ; hibernates as
larva.
Rare and local; restricted to oak woods ; of lofty and noble flight.
More often seen than caught. Like V. Atalanta this fine butterfly
has been taken both at light and sugar.
The larva appears to have been first discovered in Essex (and in
England) by Mr. Drury. Moses Harris, in his "Aurelian : or Natural
History of English Insects, namely, Moths and Butterflies" (1766),
gives in plate iii. two figures of the caterpillar, and remarks upon