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Suffolk Natural History, Vol. 39

Other Arthropods Recorder’s Annual Report 2002 As was the case last year, there are no additions to the county checklists or new sites for rare species to report. The most noteworthy records of 2002 resulted from pitfall trap samples collected by Jim Askins on Sudbourne Beach. The Essex Field Club, in the form of Peter Harvey and Ray Ruffell, also contributed a number of records; all involved common species but they were nevertheless important as they were from poorly recorded areas of the county. Porcellio spinicornis is a relatively large and readily recognised woodlouse typically found on walls with lime rich mortar. Its natural habitat is thought to include calcareous screes and cliffs but the scattering of Suffolk records are mainly from churches. However this was the most abundant woodlouse in the pitfall trap samples from Sudbourne Beach and it may be that coastal shingle is a previously unrecognised natural habitat for the species. Despite its distinctive appearance Porcellio spinicornis is often difficult to find on walls, even where it is known to occur, due to its nocturnal habits. In daylight hours it hides in deep crevices, a microsite to be found in abundance in shingle. Shingle is a difficult habitat from which to record invertebrates during the day never mind at night and, at least until recently, little trapping has been attempted. Considering these difficulties it would not be surprising if shingle had previously been overlooked as a natural habitat for Porcellio spinicornis. The same pitfall trap samples also contained specimens of the woodlouse Porcellionides cingendus. The only previous Suffolk records for this species are from further south on Orfordness. Although it is known from some sites in Essex, Porcellionides cingendus is essentially a species of the western and south-western coasts of Britain and Sudbourne Beach appears to be its most northerly location on the eastern coast. In my report last year I mentioned a record of Polyxenus lagurus, a millipede with a most unusual appearance, from Ipswich. Many more of these animals were found in the pitfall traps on Sudbourne Beach this year. Although it is seen most commonly on old walls or under bark on trees there are a few records of Polyxenus lagurus from coastal sites. As with Porcellio spinicornis it may be that the difficulty of recording small invertebrates in shingle explains why this millipede has not been reported more often from such sites. There were no centipede records in 2002 that are worth commenting on but a new species is likely to be added to the Suffolk checklist in the near future. One of the common geophilid centipedes, previously recorded as Geophilus carpophagus, has recently been shown to comprise two different species, namely Geophilus carpophagus and Geophilus easoni. This means that the specimens supporting all previous records of Geophilus carpophagus need to be checked and where no specimens exist the record now has little value other than indicating a site that needs to be revisited in the future. All of the specimens seen so far are Geophilus easoni but I fully expect Geophilus carpophagus s.s. to be present in the county. Paul Lee Oakdene, The Heath, Tattingstone, Ipswich IP9 2LX

Trans. Suffolk Nat. Soc. 39 (2003)

Other Arthropods Recorder’s Annual Report 2002  

Paul Lee

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