280
THE ESSEX NATURALIST
He also showed, on behalf of Mr. Ross, a specimen of Badhamia foliicola
collected during the Club's fungus foray by Mrs. Ella P. Ward.
Mr. Richard Ward showed colour photographs to illustrate some obser-
vations made by Mr. Bartrop and himself last May on the behaviour of a
weazel with its prey—a young rabbit. The incident took place on a
railway-track and thus gave opportunity to observe the effect of passing
trains on the actions of the weasel.
The meeting was then closed and members took tea in one of the rooms
of the College.
Ordinary Meeting (979th Meeting)
SATURDAY, 27 NOVEMBER, 1954
This meeting was held in the Physics Lecture Theatre of the West Ham
College of Technology at 3 p.m. In the absence of the President, the
chair was taken by Mr. L. S. Harley, Vice-President.
Mr. A. B. Sidle, of 18, York Road, Chingford, London, E.4, was
elected to membership of the Club.
Mr. Foster showed a clockwork roasting-jack and a candle lantern of
late 19th century date.
Mr. Pratt showed a cocoon of Anilastus ebeninus spun up inside the
skin of its host larva (Gonepteryx rhamni) and the hyper-parasite
Mesochorus gracilentus which had emerged therefrom; also Casinaria vidua
with its empty cocoon spun up on the twig beside the empty skin of its
host larva Abraxas grossularaiat.
Mr. Pratt showed specimens of parasitic Hymenoptera and described his
exhibit as follows: "At the top of Little Warley Common there is a tree
of Alder Buckthorn. This tree is evidently a favourite with the females
of the Brimstone butterfly (Gonepteryx rhamni), for whenever I have
looked at. the right season I have found a number of larvae of this butterfly.
I have usually tried to rear some of the larvae and, although I have bred
butterflies from some, others have prematurely ended their lives as the
curious small bloated specimens which I exhibit today. This phenomenon
is due to the fact that the larva? are parasitized by Anilastus ebeninus
(Ichneumonidae, Campoplegini), the larva of which feeds inside the butterfly
larva and then spins its cocoon inside what is left of the host. The more
usual habit of such parasitic larvae is, of course, to leave their host when
fully fed and to spin their cocoons outside the carcase.
"The fly which I bred from this cocoon proved to be, not the parasite
itself, but one by which it in turn had been parasitized, the hyper-parasite
Mesochorus gracilentus.
"Both these species were bred by my grandfather, Mr. G. C. Bignell,
who recorded them in Buckler's Larvae of the British Butterflies and Moths,
vol. 1, in 1886, and I am indebted to Mr. G. J. Kerrich, of the British
Museum, for kindly identifying them for me.
"I also show, for comparison, a cocoon of the parasite Casinaria vidua
spun up on the twig beside the remains of its host, the larva of the Magpie
moth (Abraxas grossulariata)."
Mr. Pratt also showed a male specimen of the Grayling butterfly
(Eumenis selene) taken on the marshes of the Roman River at Rowhedge
last August.
Also a specimen of the Large White butterfly which, when killed, was
found to be gripped by the costa in the jaws of a wasp. The two insects
remain locked together long after death.