4 
NOTES OF OBSERVATIONS 
necessarily altered, I now give this year’s Notes in accordance with 
those on our new sheet. 
Plusia Gamma. 
1. Plusia Gamma. Silver Y Moth. The unusual amount of 
appearance of this moth has been as remarkable as that of the Colias 
Edusa in 1877; and as we rarely are enabled to trace the march of 
one of these vast insect appearances forward, I take leave to offer a 
note, which has been forwarded to me by Mr. Fitch, of Maldon, of the 
progress of the swarm, which appears to have been composed, at 
most of the successive points noted, of the moth Plusia Gamma , as 
well as of the Painted Lady butterfly, Vanessa Cardui. The swarm 
appears to have started from the North-west of Africa and travelled 
in a north-east direction, was observed at Algiers about April 15tli to 
20th, it reached Valencia, and was spread over Spain, and also 
present in the Balearic Isles from April 26tli to May 3rd, and crossed 
the Eastern Pyrenees on May 26tli and 27tli. It next appeared in 
the South-east of France, Switzerland, and Northern Italy; and on 
the morning of June 5tli thousands of living specimens were found on 
the snow at the Hospice of St. Gothard. It was then distributed over 
Germany and Austria at dates of appearance noted as being from 
June 7tli to 16th. Another column crossed the Mediterranean to 
Sicily, and spread northwards over Italy in June. The more westerly 
end of the migratory swarm reached Strasburg from June 3rd to 9th; 
Paris and its environs were apparently not reached till June 15th. 
The appearance on our South coast was noticed on June 10th; and 
the moths were subsequently observable throughout the three kingdoms. 
Mr. Norgate mentions the Plusia Gamma as unusually abundant at 
Sparliam, near Norwich, on June 12th and 13th; and it was also 
noticed on the 13tli at Maldon, Essex. Subsequently it occurred in 
enormous quantities at many localities, the numbers, however, diminish¬ 
ing (as far as appears from the observations sent in) as the points of 
observation became more northerly. At Exeter, Mr. Parfitt mentions 
