92 Notul. Odonatol., Vol, I. No. 5, Pp. 85-96. June
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Notul. odonatol., Vol, I. No. 5, 85-96. June I. 1980 92 pp. Proceedings of the First Meeting of British Dragonfly Recorders, London, April 7, 1979 Compiled by D.G. Chelmick ”Bredon”, High Beech Lane. Haywards Heath, Sussex, United Kingdom The status and distribution of the British published in 1978 and included all records Odonata received up to May 1977. By the end of 1978 The Provisional Atlas for Odonata was so much additional information had been Notul. odonatol., Vol. I, No. 5. pp. 85-96, June I, 1980 93 Ireland and the received that it was felt necessary to update British Isles (excluding the maps. This was carried out during the Channel Islands) is 2660. Records have now and 1979 and been 1161 of these. winter early spring of it was received from Express- these maps that formed the basis of this ing the squares recorded for each species as session. would like sincere of the total recorded I to express my a percentage squares. thanks to Bill and Bob Merritt who carried out the majority of the updating work and Table I also to David Parker from whose notes much of this summary derives. Recorded Cat. No. squares The British list Current No. of published infor- of spp. as % mation on what constitutes a British species total is unclear and considerable discussion took place. It was generally agreed that all species 1 5 > 38% recorded from the British Isles should be in- 2 11 18-30% cluded but that vagrants should be classified 3 5 8-14% as such. The Provisional Atlas for Odonata 4 6 4- 7% (Heath. 1978) includes 44 species. Three of 5 11 <2.5% these are migrants only; Sympetrum flave- 38 lutai post 1961 olum (L). S. fonscolombei (Sel.), and S. breeding spp. vulgatum < L.). Three further species have not and all been seen for many years are, in pro- extinct; of British fauna bability. they are Coenagrion ar- the status the can be categor- C. and Table I. matum (Charp.), scitulum (Ramb.) ised as shown in Unfortunately it is Oxygastra curtisii (Dale). Additional vagrant impractical to produce such a table for pre- which be the 1960 data. We species, must added to list, are can, therefore, draw no con- 5 records whether the fauna as follows: species with isolated clusion as to pattern of our from mainland Britain namely, Gomphus is changing. However, with the latest data, flavipes (Charp.). Aeshna affinis (Vander L.), we can look at individual species and con- Hemianax ephippiger(Burnt.), Somatochlora sider their status. alpestris (Sel.) and Lestes viridis (Vander L ); Of the 21 species recorded in categories the 1-3 all 4 3 further species recorded only from but showed an increase in Islands recorded of between 34 Channel namely Sympecma fusca squares and 50%. This (Vander L.). Lestes barbarus (Fabr.) and Cro- compares with an overall increase of 43%. cothemis erythraea (Brulle). In categories 4 and 5. 10 species increased In conclusion the British List comprises 52 species. 38 currently breeding ( Lestes dryas Table II Kirby probably only in Ireland). 3 former breeding species now extinct and 11 vagrants. % increase recorded „ Cat. in recorded - The status of the British Odonata In the Species No. squares Provisional Atlas (HEATH. 1978) there are a ((1977-1979)1977-1979) total of 4977 species 10 km square post 1961 records for Great Britain (excluding Ireland BrachytronBrachylron pratense 4 27% and the total Channel Islands). This is pro- Ceriagrion tenellumlenellum 4 26% duced by counting all black dots for each Sympetrum sanguineum 4 23% The species. latest maps (produced February CoenagrionCuenagrionpulchellum 4 12% 1979) have added a further 2115 records which Libellula fulva 5 8% represents an increase of 43% in under two AeshnaA eshna isosceles 5 nil years. Lestes dryas 5 nil The total number of 10 km in the squares 94 Notul. Vol. No. odonatol., I, 5, pp. 85-96, June I, 1980 by between 47 and 133%, which probably scarce only where FMT is less than 0.6° C. the The for of who indicates under-recording in past. Finally, those us have always remaining 7 species, however, increased by wondered why Leucorrhinia dubia (Vander between 0 and is has been from 27% only. 1 1 these species that L.) never recorded the splendid must be considered vulnerable and of Dorset and the New Forest, it they are bogs may listed in Table II. It is encouraging that none simply be that the winters are notcold enough. of these has shown a real decline. Mention, Discussion of habitat requirements and be of however, must made the situation re- ecology of individual species proved to be Lestes This and and garding dryas. insect has not been lively informed only a brief summary A number recorded in the mainland of Britain since of salient points can be given here. and that of the of 1972, it is generallyfelt a combina- observers noted occurrence Platy- ofclimatic conditions tion and major drainage cnemis pennipes (Pall.), generally a riparian schemes Eastern have in England brought species, in large colonies on lakes. Dr M.J. about its extinction. It remains a British Parr gave an explanation of the female colour breeding species from Irish colonies alone. varieties of both Ischnura elegans and Ceria- consider those tenellum that he Finally, we must species grion (de Vill.) explaining was interested in which, even though they appear to be stable, hearing from any observers in such small number of that about colonies of the latter which occur a squares possessed vulnerable. PER RING & of the all red female they are still a high proportion rare FARRELL (1977) considered species occur- form,erythrogastrum. Dr N.W. Moore ring in 15 or less 10 km squares to be rare explained the attempts enough for inclusion in the British Red Data he had made reintroducing C. tenellum at Book for vascular plants. Four species of Wood Walton Fen N.N.R. in Cambridgeshire. fall into this number Pools created in the acid dragonfly category (with were remnant peat and introduced from of recorded squares), viz. Coenagrion mer- adults athreatened site in curiale Somato- Dorset. The of adults (14), Aeshna coerulea (12), next generation appear- ed chlora arctica (II), and Coenagrion hastula- two years later, but the colony was wiped in tum (4). In conclusion, of the 38 breeding out 1976, possibly as a result ofthe drought. Dr Moore species. 11 can be considered vulnerable and then went on to explain his dis- of three warrant more intensive recording and study covery new colonies for Lestes dryas in future. in Ireland, noting that the habitat, heavily vegetated lowland dykes, was very similar The distribution and ecology of the British to that where he had known the insect in Odonatai— This discussion session opened Sussex in the I940’s. the felt with consideration of the possible relation- Moving to Anisoptera, it was that ship between distribution and environmental colonies of Brachytron pratense (Mull.) on acid factors, particularly temperature. Overlays pools were the exception and that the of environmental factors for use with dis- preferred habitat was lowland dykes. Details tribution used of of maps (I.T.E.. 1978) were to were given surveys carried outon one our illustrate the discussion. The most interesting most local species, Aeshna isosceles (Mull.), factors appeared to be the February Minimum whose breeding colonies are threatened by and July Mean Temperature isotherms (FMT drainage schemes. and JMT). For example, Ischnura pumilio Graham Vick gave details of his Scottish carried in which indicated (Charp.) and Coenagrion mercuriale (Charp.) survey out 1978 that FMT A. do not occur where is less than 2.2° C, coerulea (Strom) was fairly widespread in whilst C. hastulatum (Charp.) breeds only in Wester Ross, breeding in sheltered boggy often with Somatochlora that part of Scotland where FMT remains pools arctica (Zett.) below and Leucorrhinia dubia. The indicator 0.6° C. Turningto our more widespread plant for this species, C. puella (L.) and Calopteryx splen- species habitat was the sundew, Dro- JMT below The showed that dens (Harr.) become rare as drops sera anglica. survey also I5°C, and Ischnura elegans (Vander L.) is Somatochlora metallica (Vander L.) and Cor- 1. No. 85-96, June I, 1980 95 Notul. odonatol., Vol. 5, pp. locali- dulia aenea(L.) were still present in Scotland valuable in pinpointingexact breeding and Eve Aeshna Harry reportedon acolony of ties of rare and local species. about 150 miles cyanea (Mull.)near Inverness, north of its usual range. The Mapping Scheme The final session took the form of an open The collection and study of Odonata exuviae forum, the discussion ranged from such the of the Channel (contributed by G.S. VICK) subjects as inclusion four and how The study of exuviae offers advantages Islands in the scheme, vagrant species the to the field odonatologist. Firstly, it allows they should best be indicated on maps and all whether him to work in weathers, secondly it en- finally more detailed habitat informa- the the ables him to determine precise breeding tion should be requested on recording that habitat localities of particular species, an extensive card. It was generally agreed collection can be made without affecting data would be desirable and that ultimately number populations and finally, a of species there should be some more quantified ap- often ob- rather than can be found which are difficult to proach to recording simple pre- the lines serve as adults. sence or absence, possibly on of It is important, when searching for exuviae, SCHMIDT (1979). examine casual to vegetation very closely; Finally the master species map produced This observation at a distance is rarely successful.