LEPIDOPTERA IN SOUTH-EAST ESSEX 123
there were over 200 in the trap. These must have corne two miles from
Leigh Marsh, the day had been hot and close and the first big flights of fly-
ing ants had appeared. The phenomenon was repeated on 6th and 9th August,
when also the ants were much in evidence, clearly the same conditions
caused swarming in each insect. In A. nivea the female is usually wingless
and lives under or on the surface of the water, but when swarming conditions
arise females appear at least twice the size of the males with even ampler
wings and fly with them. The males on these flights also were larger than
those I have taken in ditches and lakes. The swarming habits of this particular
insect would seem worth studying.
A short list of marsh and salt-marsh insects taken at my garden light
(on high ground at the very back of the town) would seem of interest. Leucania
straminea Treitsch, one female, 28th July. Leucania obsoleta Hubn., one
male, 26th June. Spaelotis ravida Hubn., one male, 6th July. Schoenobius
gigantellus Schiff., one female, 24th June. Crambus salinella) Tutt, one female,
6th July. Crambus paludellus Hubn., one female, 7th July, and another
female came to light in Belfairs Wood on 8th July. Agdistis bennetii Curt.,
one, 29th June, and about a dozen in early August. Phalonia affinitana Dougl.,
one 29th June, one 30th June. Bactra scirpicolana Pierce, two 29th June,
two 30th June.
From these figures it would appear that (on warm damp nights especially)
marsh and salt-marsh insects rise in the air and are carried on the wind till
attracted by a strong light. The nearest salt-marsh where the foods of
bennetii, affinitana and scirpicolana grow is at least two miles as the crow
flies from here, and I have not seen gigantellus or paludella) within four.
Butterflies at North Fambridge
in 1957
By JACK T. FRIEDLEIN
THIS proved to be the worst butterfly and moth year for ages. In spite of
long hot spells up to July even the normally common species were
absent or very scarce.
For instance only four Peacocks were recorded during the whole year.
Small Tortoiseshells were very scarce. Commas normal. Silver-washed
Fritillaries seemed to be holding their own in one or two large woods but
were absent from some of the usual strongholds. White Admirals a poor
season. Kinglets and Skippers were low in numbers. Common Blues and
White-letter Hairstreaks were up to normal on the farm but Purple Hair-
streaks in the woods were scarce.
Only three Painted Ladies were recorded but Red Admirals totalled over
seventy for the season. No Clouded Yellows were seen and migrant moths
were scarce or absent. If this scarcity continues in the coming years there
must surely be a reason other than weather conditions. Perhaps the wholesale
use of killing sprays throughout Britain will eventually reduce our insects to
extinction or are the reproductory powers of insects being affected by atom
bomb experiments.