MIGRATION AND DISPERSAL OF INSECTS : LEPIDOPTERA. Pal 
common, as also was C. edusa), 1858 (common), 1859 (one record), 
1867 (one record), 1868 (very abundant, edusa was not common), 1869 
(one record), 1870 (scarce), 1872 (common, not so edusa), 1875 (abun- 
dant), 1876 (common). C. edusa was abundant in 1804, 1808, 1811, 
in 1825 (one), 1826 (very abundant), 1831 (plentiful), 1838, 1835 (both 
species common), 1836 (common), 18389 (common, many in June), 
1843 (abundant), 1844 (very common), 1845 (scarce), 1847, 1848 (one 
record), 1851 (one record), 1852, 1855 (common), 1856 (common), 
1857 (very common, recorded to November 18th), 1858 (very common, 
particularly in June, also to November 7th), 1859 (very abundant), 
1861 (scarce), 1862, 1865 (common), 1867 (several), 1868 (common, 
but C. hyale much more so), 1869 (several), 1870 (scarce), 1871 (one 
record), 1872 (not uncommon), 1875 (very common), 1876 (common). 
In 1877, C. edusa swarmed from Orkney (W. Tait) to Land’s End 
(Miller), and from Pembroke (Barrett) to Lowestoft (Laddiman). The 
spring abundance was marked about the middle of May, chiefly in the 
south and west, and by the end of the first week of June the insect was 
pretty well distributed. Continuous broods were developed throughout 
the summer and imagines emerged in the open until November, and yet 
in 1878, the only records appear to be three imagines seen on April 
18th, in Reading and Oxford, three others at Ryde, Isle of Wight, on 
April 22nd, one on May 18th, in one of the north London suburbs, 
and in the autumn scarcely a specimen was observed, suggesting that 
the few that survived the winter were not sufficiently powerful to 
propagate with any degree of success. In 1879 immigrant C. edusa 
were observed in May and June, but the wet weather must have 
decimated the larvee, as the autumnal emergence was only abundant 
in a few places on the south and south-eastern coasts. The most 
recent occasion on which both species appeared in the same year took 
place in 1892, when, during the first week of June, the sudden appear- 
ance of specimens was almost simultaneously announced from a 
majority of the English counties, C. edusa being, however, much more 
common than CU. hyale. These, which were without doubt immigrants 
—for experience suggests that our climate is unsuited to the larve of 
this species during the winter (see, Ent. Record, vii., pp. 250-253)— 
soon laid their eggs, and, by the end of July, their progeny began to 
emerge, and our clover-fields became quite brilliant with vast numbers 
of both species. Along the Mediterranean littoral, where the climate 
is so favourable to the existence of many species, C. edusa is to be 
found in abundance every year, a succession of broods occurring, 
whilst the almost entire absence of cold weather does away with the 
necessity for prolonged hybernation. From these centres it would 
appear to spread, sometimes in vast numbers, so as now and again to 
reach our shores, or even to Scandinavia, but more frequently in 
smaller numbers, its dispersal being confined to the southern countries 
of Europe, where the species has the greatest chance of existence. 
Bringing its southern habits to England when it immigrates, it 
lays eggs which in due course produce a summer emergence in 
July and August, the females of this brood immediately laying their 
egos as they would have done in the warmer climes from which their 
parents came. ‘The caterpillars ernerge from the eges, and for a short 
time all goes on well enough, and a fresh lot of imagines may even 
emerge in October and November and the females lay their eggs, but 
