PROCEEDINGS OF THE

ROYAL ENTOMOLOGICAL SOCIETY

OF LONDON

SERIES C. J O U R N A L O F M E E T I N G S

VOLUME 27 No. 7, 1962

ORDINARY MEETING

WEDNESDAY, 7th NOVEMBER, 1962, a t 5.30 p.m. (Tea 5 p.m.)

AGENDA

1. Confirmation of the Proceedings of the Ordinary Meeting held on 10th October, 1962. 2. Recommendation of candidates for Fellowship. First reading. 3. Recommendation of candidates for Fellowship. Second reading. 4. Announcement of election of new Fellows. 5. Council’s list of nomination for Officers and Council for 1963. 6. Admission of Fellows. 7. Papers accepted for publication in the Transactions. 8. Exhibits.

9. Communications.

1. Dr. J. €I. Mundie ( Preshwater Biological Associatim, Ambleside, Westmorlafid)

Population dynamics of Chironomidae in Esthwaite Water

[ABSTRACT]

In a rich shallow lake summer stratification and de-oxygenation of the hypolimnion impose steep physico-chemical gradients which largely determine the distribution of the benthic insects. In a study of the insect ecology of Esthwaite Water in the English Lake District the distribution of larvae was established by taking surface mud cores along transects. Submerged traps were used to catch pupae in the littoral, sublittoral and profundal regions. The traps were designed to prevent loss of insects once they had been caught. The diurnal periodicity in emergence of the commoner species was analysed by means of hourly plankton hauls.

The density of larvae ranges from 21,000/m2 in the littoral to 3,500/m2 a t 15 m. A t 3 m. 54 species occur, a t 7 m. 38 and a t 15 m. 12. Most of the Orthocladiinae were found in the shallow littoral. Here the zonation of species is steep. At 7 m., which is in the thermocline in midsummer, Tanytarsus lugens Kieff. is the commonest species. The deeper water has a familiar community of Chironomus anthracinus Zett., Procladius spp. and the Culicid ChaoborusJlavicans Mg. Six of the seven British species of Procladius occur in Esthwaite Water and are the most abundant insects in the lake. Their larvae are predatory and range over the lake, unlike those species whose requirements restrict them to particular zones. Procladius (Psilotanypus) rufovittatus v.d. W. is a univoltine species. In June its pupae ascend to the surface mainly a t 2.30 a.m. ChaoborusJlavicans is also univoltine. It emerges in June mainly a t 3.0 a.m.

Growing knowledge of the insects of Esthwaite Water is permitting more detailed

26

quest.ions to be asked on the biology of species and : t i l o w comp:trison to be made with communities in other lakes.

2 . Dr. Bryan P. Beirne (Entontology Eleseurch Iiistit utc for Biological Coiatrol, Bellcuille, OntcrTio)

Biological Control Research in Canada

[dBSTRACT]

Research in biological control in Canada was reorganised in recent years. Because of past failures relatively more resexrch is now done before natural enemies are intro- duced. This covers a number of familiar British insects that have recently beconie established and are increasing rapidly. Microbial pathogens, especially entomophilic nematodes, have much potential for use in place of chemical pesticides. Control by environmental manipulation, or conservation, is being given increasing attention ; aspects studied include the influence of non-crop plants on crop pests through the natural enemies of the latter, and effects of physical factors, such as ultrasonics aEd atmospheric electricity, on insect behaviour. Research in population ecology is being given special and increasing emphasis. I n t e p t e d chemical and biological control procedures are the ultimate solution to most pest problems, but there are important practical barriers to their development.

NOTICES The next meeting will be held on Wednesday, 5th December, 1962: Dr. N. E. Hickin.-The occurrence of the furniture beetle Anobium pu~ctatum

(Degeer) in Britain.

Handbooks f o r the Identijcation. of British Insects The attention of Bellows is drawn to the fact that orders €or parts of the Handbooks

should in future be sent to Mr. E. W. Classey, 353, Hanworth Road, Hampton, Middlesex, who has been appointed the Society’s agent for sales of this series. Standing orders already placed with the Society have been transferred and will be continued automatic- ally. It has been necessary to apply a surcharge of 334% to Handbooks published before 1960.

Annual subscription Fellows are reminded that, commencing with 1963, the basic annual subscription

has been increased to .€5 0s. Od. It is hoped that as many Fellows as possible will pay the subscription by bankers’ order, and that those who have not already done so will complete and return the form, sent to them with the Treasurer’s letter in July, as soon as possible.

Library The Council of the Society give notice that in future the Society’s library will be

closed on Saturday morning. The library is open from 9.30 a.m. to 5.0 p.m. from Monday to Friday, and until the close of the meeting on meeting days. Books may be borrowed by post.

PROCEEDINGS OF THE ORDINARY MEETING HELD ON ~ O T H OCTOBER, 1962 Professor G. C. VARLEY, President, in the Chair.

Present, 75 Fellows and 17 Visitors. The minutes of the Ordinary Meeting held on 4th July, 1962, were confirmed and

The names of the following candidates for election were read for the first time : signed by the President.

27

Mr. John Hemingway Barrett, B.Agr.Sc.; Mr. Hemendra Kumar Bhowmik, B.Sc., M.Sc.; Mr. James Roy Cullen ; Dr. John Brand Free ; Mr. Michael John Friend ; Mrs. Grace Hickling, M.A.; IClr. Christopher John Hodgson ; Mr. John Robert Morgan, B.Sc.; Mr. Subramania Nagarajan ; Major Anthony Bedford Russell ; Mr. Keshava Chandra Sharma ; Mr. Mohan La1 Thakur, M.Sc.; Dr. J. D. Thomas ; Mr. John Richard George Turner, B.Sc.; Miss Lena Kay Ward ; Mr. Fred Witham ; Mr. Cyril James Thompson Willoughb y.

For the second time (taken as read) ; Mr. Mohammad Abdullah ; Mr. Raul Mac- Gregor ; Mr. Garnet Frances Mason ; Mr. John Morley.

The Secretary read the names of the following newly elected Fellows of the Society : Mr. John Sam Aikins, 24, Rita Road, South Lambeth, S.W.8 ; Mr. Richard S. Balter, 5, Abingdon Drive, Ruddington, Notts.; Mr. Dick L. Deonier, Department of Zo010,py and Entomology, Iowa State University, Ames, Iowa, U.S.A.; Mr. Osman Ibrahim Gameel, Department of Agricultural Entomology, King’s College, Newcastle-upon-Tyne; Mr. Laurence Aylmer Haldane, Brookside, Corfe, Nr. Taunton, Somerset ; Dr. Jehoshua Kugler, M.Sc., Ph.D., Department of Zoology, Tel-Aviv University, 155, Herzl Street, Tel-Aviv, Israel; Mr. Shashi Kumar, Department of Zoology and Entomology, Rajas- than College of Agriculture, Udaipur (Rajasthan), India ; Dr. Derek Alan Robertson, B.Sc., Ph.D., Dargie Cottage, Station Road, Invergowrie, by Dundee ; Mr. Joseph C. Schaffner, Department of Zoology and Entomology, Iowa State University, Ames, Iowa, U.S.A.; Mr. Kenneth George Smith, 51, Boundary Road, Wood Green, London, N.22 ; Mr. Gordon Dennis Trebilcock, 15, Elm Road, Barnet, Herts.; Mr. Brian John Wood, 103, Moore Road, Mapperley, Nottingham.

The President said that since the last meeting news had been received of the death of an Honorary Bellow of the Society, Dr. George Arnold, formerly of the National Museum of Southern Rhodesia, who had been a Fellow of the Society since 1907 and became an Honorary Fellow in 1949. He also reported the death of R. S. Bagnall, elected a Fellow in 1904.

Thanks were voted to donors of gifts to the Library since the last meeting. Mr. G. L. Angel1 signed the Obligation Book and was admitted a Fellow of the Society.

The Hon. Miriam Rothschild and Dr. John Parsons (a visitor), gave a paper on the pharmacology of the poison gland of the Locust Poekilocerus bufonius Klug, an abstract of which appeared on pages 21 and 22.

In the discussion which followed, Dr. Parsons said, in reply to an enquiry by Sir Boris Uvarov, that the food plant used in his experiments was dandelion. Sir Boris remarked that, whereas P. hieroglyphicus Klug would feed on grass in captivitiy, in nature it fed only on poisonous plants. He also asked whether the blood had been tested for the toxin, which would increase the available supply. Dr. Parsons replied in the negative.

Mr. M. E. Solomon asked whether insects which fed on noxious plants wereymsually confined to such plants, or those of similar composition. Possibly they might be phyeio- logically adapted to certain substances in these plants and unable to use foods lacking it. Miss Rothschild replied that almost every case had to be considered separately, but there was some evidence that once an insect had turned to eating poisonous plants it could eat some but not all other poisonous plants, and there was some curious unexplained connection between the tolerance of one poison and certain other poisons. Miss Roths- child continued, in reply to an enquiry by the President, that she did not know how the burying beetle (Necrophorus fossor Erichson) or the moth, Utetheisa bella Linn. shown in the slides illustrating her paper produced froth, but in the case of N . fossor and N . investigator Zett. the froth was very offensive and the beetles stridulated a t the same time as they produced it. The defensive h i d of N . fossor was brown and that of N . investigator white.

Dr. J. D. Csrthy gave a paper on the orientation of Gyrinus aeratus Stephens (Cole- optera : Gyrinidae), an abstract of which appeared on page 22.

The discussion which followed was opened by the President, who asked whether the

28

reactions of the beetles showed any connection with their age or the season of the year. Dr. Carthy replied that no long term changes had been studied but i t was known that the sex of the beetle made no difference. In between runs they were kept in tubes in the dark but did not live for more than three days under these conditions.

Mr. C. N. Hawkins asked whether n+id direction and the effect of vibration, which would vary with the distance from the river, had any effect on the movement of the beetles. Dr. Carthy replied that the river used (the River Stour a t Flatford, Suffolk) was very sluggish and vibration probably a negligible factor. Wind was only a disturbing feature ; the beetles would battle against it and it did not affect the direction they took. Mr. Hawkins suggested the beetles might be sensitive to some odour given off by the water.

Dr. H. E. Hinton asked whether the old experiments of Hatch were really valid and Dr. Carthy replied that he thought they very possibly were. Dr. Hinton expressed some surprise a t Dr. Carthy’s mention of the Gyrinids coming to the bank of the river a t night. He thought they usually remained quite still on the water. Mr. R. W. J. Uffen added that he had himself observed a swarm at Flatford which remained motionless on the water under bushes under a tree all night. Dr. Carthy stressed that this had been only a suggestion, put forward in a desire to give meaning to apparently meaningless behaviour !

In reply to an enquiry by Mr. L. R. Cole, Dr. Carthy agreed that it was possible that these beetles stridulated. Although they might make a noise in the hand, he did not think this to be stridulation, but high frequency sound was not ruled out. A strong smell of malt was given off by the insect when handled ; perhaps secretion aided in the cohesion of the swarm.

Dr. P. T. Haskell asked whether scent trails and starting the beetles from different places had been tried. Dr. Carthy replied that experiments had been made with turning the pieces of paper between runs, but without effect.

Miss Rothschild commented on the attraction of water for certain moths, especially when released from traps, adding that different species were even selective in their choice of salt, sweetened or plain water. Dr. Carthy said he had not done any comparable tests, but felt that as the beetles would head away from water, such a sensitivity seemed unlikely.

Mr. R. L. E. Pord said he thought there were many as yet unexplained phenomena in the gregarious behaviour and direction finding of insects. He quoted a moth which could return to a particular tree despite dispersal over a wide area of woodland. Dr. Carthy said that the displaced Gyrinide did not necessarily return to their own swarm but joined the first one they found. Dr. J. S. Kennedy suggested that as these beetles were said to be taken by cranes which found them distasteful, the need for the ability to return to the river might arise when they were dropped on the bank by predatory birds.

Dr. Carthy added, in reply to another enquiry, that using mirrors to change the sense of position of the sun had not produced any result.

Mr. Ford suggested that the beetles might be attempting to communicate with each other but Dr. Carthy said that in his experiments each beetle was kept in solitary con- finement, except for mass runs, and he never gained the impression that they might be communicating.

PAUL FREEMAN, Honorary Secretary.

PRINTED BY ADLARD AND SON, LIMITED, BARTHOLOMEW PRESS, DORKING.