Bijdragen tot de Dierkunde, 55 (1): 16-24 — 1985 Distribution patterns in British Chilopoda by A.D. Barber Plymouth College of Further Education, King's Road, Devonport, Plymouth PL1 5QG, United Kingdom Abstract to occur in more easily sampled microsites often in apparently large numbers compared with the Twenty-one nonmaritime species of chilopod are recorded from northern Britain and a further fourteen from the frequently soil-dwelling geophilomorphs. Ap- All the characteristic of north- records have been made for South. northern species are proximately 1,200 with the of Lithobius Leach ern Europe exception variegatus both Lithobius forficatus and L. variegatus whilst but the remainder include both Lusitanian and central the number for Brachygeophilus truncorum and European species. Geophilus carpophagus are approximately 450 and An examination of distribution in relation patterns to climate that be 430, respectively. suggests spring/summer temperatures may in for L. of the records based visits in- significant influencing occurrenceexcept variegatus Many are on to where isotherms show a better correlation January dividual sites on one or only a small number of although problems arise when altitudinal effects are ex- occasions, so species will clearly have been amined. It is that urban “heat suggested areas acting as missed. Andersson (1983) estimated that litter islands” in where may permit some species to occur areas and hand would find they would otherwise be absent. sifting sorting on average 50% of the species in a locality each time. The comparatively large number and wide scatter of records however clear of gives a fairly picture INTRODUCTION the distributionfor rather general many species than simply that of recorders. Isolated from the European mainland the fauna of Britain be chilopod may predicted to consist of a species list broadly similar to adja- SPECIES WIDESPREAD IN BRITAIN cent mainland areas such as the Netherlands, Belgium and France together with what is If a line is drawn approximately from the element of nonmaritime usually described as a Lusitanian Mersey to the Wash, only 21 and of the French Atlantic and Iberia. maritime north species coast 3 chilopod species are recorded It may be anticipated that certain widespread of this, all the nonmaritime, with the exception European species may be absent. of Lithobius variegatus Leach, being members of Accumulated distributional data collected the fauna of the Netherlands and Scandinavia. since the of Eason's standard work The total number of would publication species appear to (Eason, 1964) and in particular records from decline northwards until for the Shetland the Myriapod Survey Scheme (Barber & Islands only 8 are recorded in total (unpub- Fairhurst, 1974) permit a more detailed lished data from collections made in 1974 by the analysis of distribution than hitherto. Rather University of Edinburgh and Institute for Ter- than records been In more 8,000 individual have restrial Ecology, Grange over Sands). con- obtained but certain 14 recorded parts of Wales and much trast, a further species are from of Scotland still known. outdoor sites in various of southern are very imperfectly parts For Ireland there are insufficient recent data to Britain. comment in detail on its fauna (Barber, 1984a). Table I summarises the nonmaritime species recorded from Lithobiids, especially the larger species, are various areas of Britain and cer- most frequently recorded due to their tendency tain European countries. Lithobius erythrocephalus - 1985 17 BIJDRAGEN TOT DE DIERKUNDE, 55 (1) latter C. L. Koch (general European), Lithobius two not necessarily being reliable, but the tenebrosus Meinert (Scandinavia) and Geophilus seems to have a more northerly limit than the proximus C. L. Koch (Scandinavia, Netherlands) former. have not been reliably recorded from the British Geophilus electricus (Linnaeus) is very patchily L. distributedand often associated with human Isles. Pachymerium ferrugineum (C. Koch), a ac- species widespread in Europe from Scandinavia tivity, a pattern which seems to be similar to that elsewhere in northern to the Mediterranean region has only been Europe. found once in Britain, possibly a chance in- the troduction, on South coast of England It has found the (Lewis, 1960). not been on LITHOBIUS VARIEGATUS LEACH French Atlantic coast. This is the nonurban Of the commoner British species, Lithobius common large lithobiid of crassipes L. Koch (map 3) is almost ubiquitous sites throughout most of western Britain and in northern and Britain Ireland. It is also in Channel Islands eastern although not present the from recorded from Shetland and not occurring in and has recently been recorded Brittany sites. It in both and N. in Eason and Serra synanthropic occurs upland (A. Keay, litt.). (in litt.) lowland sites but in have shown that the is identical with upland areas Caernarvon- species shire (Eason, 1957) and Devon have L. borealis Lithobius rubriceps Newport ( = L. insignis instead. both Meinert In Kent and Surrey L. Meinert) a species of the Iberian peninsula, borealis and L. southern Tunisia and Morocco. crassipes are patchily distributed Italy, Sicily, whilst L. Meinert is in Lewis that this is less microps very common; (1964) suggests species Devon and Cornwall L. crassipes would seem to tolerant of climatic extremes than L. forficatus be is also L. of largely or entirely absent, as curtipes (Linnaeus) including possibly dryness C. L. Koch and L. macilentus L. Koch. This lat- climate. Eason (unpub.) has drawn attention to has distribu- eastward ter species an extremely patchy the relationship between the limits of tion; possibly its parthenogenetic habits would the species (map 2) and the 3.33° C (38° F) it from foci isotherm and there would be permit to spread easily when it January seem to with least for reached an area by chance. some agreement this at eastern Insufficient data are currently available for England. However, the situation is undoubted- L. draw curtipes to conclusions on its distribu- ly more complex. L. calcaratus C. L. Koch is but tion; a typical Detailed studies show the species to be ex- rarely dominant species of acid moorland and tremely patchily distributed at the edge of this L. has marked In Northumberland and the Scottish heath; melanops Newport a range. tendency for synanthropic sites, like L. calcaratus borders, the species is almost completely absent from it occurs throughout Britain. Andersson (1983) all types of site both lowland and upland describes correlation but is in the an inverse between L. cur- (Barber, 1984b) present upper part and L. in there would of Dale to 400 and in tipes microps Goteborg; Coquet at up m areas seem to be a "small nonurban lithobiid" niche South and West. In Cumbria it occurs in different in sites. 750 occupied by species particular upland areas up to m and is a widespread nemorensis C. in- and Schendyla L. Koch, Geophilus common species. sculptus Attems, G. carpophagus Leach, Necro- Highland areas show marked differences in phloeophagus longicornis (Leach) and Brachygeo- climate compared with the surrounding low- lands: lower the of philus truncorum (Bergso & Meinert) are temperatures (of order 6°C Britain. 1000 and widespread throughout G. carpophagus per m), greater precipitation humidity is a very characteristic animal of all types of acid and freezing temperatures above 600 m on most and winter heath moor. Data on Strigamia crassipes (C. nights (Chandler & Gregory, 1976). This L. and S. accuminata insuffi- that of 3-4° in Koch) (Leach) are means a difference temperature, cient clear older records of the the between the for conclusions, comparable to difference ex- 18 PROCEEDINGS 6th INTERNATIONAL CONGRESS OF MYRIAPODOLOGY treme East and the extreme South-West, would area from mid-Wales to Hampshire (map 4) and small occur between the coast the mountains in whilst C. pinguis is known only from a Britain those de- number certain areas of including area in North Devon. A of other scribed. between distribution animals have such Any relationship species of a southwestern and winter is for instance the temperatures clearly not a pattern, diplopods Chordeuma and straightforward one. proximum Ribaut Microchordeuma gallicum both of which The tendency of this species apparently to (Latzel) are widespread in favour in fact be more due southern and Britain upland areas may to western (Kime, 1978) the fact that it does not occur in urban and whilst Chordeuma sylvestre C. L. Koch is known from which suburban sites in general, areas a only from Cornwall (J. G. Blower, pers. substantially higher proportion of lowland, comm.). Of the British isopods (Harding, 1976) compared with upland, records are made. Metaponorthus cingendus (Kinahan) and Ar- Brandt madillidium depressum are further ex- amples of southwestern animals, the latter, in- terestingly, not having been recorded from BRITAIN SPECIES FROM SOUTHERN Ireland; Ligidium hypnorum (Cuvier), by con- trast, is southeastern. Although the January isotherms in Britain run L. pilicornis is widespread in South-West approximately North-South, those of the spring Devon and in Cornwall, especially in urban with records from and summer are approximately East-West areas, synanthropic a which fits in number of sites the South of (maps 12, 13), a pattern roughly on coast England with the distribution of animals. Rainfall and inland It tends to many (map 5). replace L. for- follows a more or less East-West pattern with ficatus almost entirely in those locations in which much of central Britain drier but its distribution is being relatively it is found very patchy with distinct in sites (map 14). Mean annual relative humidity is colonies whilst a nearby in coastal and lowest in central less than 100 will have highest areas location, m away, only which does latter England (map 15), a pattern cor- the species. Geoffroy (1983) comments on relate obviously with species distribution. competition between these two species in alpine Presumably local humidity is important but the sites, where L.