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Freshwater Invertebrate Recorder’s Annual Report 2002 Unfortunately there was no report on freshwater invertebrate recording in last year’s transactions, so the records detailed below cover both the 2001 and 2002 seasons. I shall concentrate below on invertebrates other than Coleoptera and Odonata, both of which have their own dedicated recorders. During the two seasons the county database has grown by just over 2000 records to 18,100 and the number of sites represented to around 325. This reflects the amount of time which has been invested in both data input and microscope work, but there are still many records to input and tubes of specimens left to identify. Nothing short of early retirement is needed to get up to date! Unfortunately there are still very few freshwater records sent either to the museum, or myself although those that come in are very welcome indeed. Therefore I must take this opportunity to thank those who have contributed records for the database, most of whom are mentioned below, to which I should also add David Nash, Paul Lee and Neil Sherman. Having finished the survey work at Framlingham Mere, a start has been made in recording at Redgrave and Lopham Fen. Over 30 species were quickly taken in the spider pools (though no raft spiders) and, despite some records technically being in Norfolk, the pools and river in the Suffolk parts are looking very promising indeed. Redgrave has provided the first county records for three Cladocera species, Ceriodaphnia reticulata var serrata, Daphnia hyalina and Daphnia hyalina var. lacustris. In addition the species Eurycercus lamellatus is common in both pools and the river and, as reported in my last article, is increasingly taken in a wide variety of habitats and locations in the county. 16 different species of aquatic Heteroptera were recorded here, a list that included both Cymatia bonsdorffii and C. coleoptrata, and also the full trio of Hesperocorixa linnaei , H. moesta and H. sahlbergi. The latter species is by far the commonest being recorded 5 times more frequently than H. linnaei and 12 times more often than H. moesta. Recording all three from a single site is certainly unusual. Another major recording effort in the past two seasons was a ‘tour’ of the River Brett almost from the source to its confluence with the Stour. The species list obtained confirms this as a particularly rich river for the West of the county, putting my own village’s namesake, the Box, to shame even though they join the Stour within a short distance of each other. Six species of Ephemeroptera can be found at some sites on the Brett, and as seen elsewhere the two species Centroptilum luteolum, and C. pennulatum are often found together on this river. Whilst not as common as the Baetis rhodani or Cloeon dipterum the Centroptilum species do seem to be on the increase. Before moving away from the Stour system it may be interesting to note that, although living with a tributary of the River Box flowing through my garden (Hol Brook in fact) and despite my garden stream being rather an over recorded site, I had never found the large mayfly larva of Ephemera vulgata there. So I was surprised to catch not one but three single adult male specimens in display flight over my own lawn. This was in June, July and

Trans. Suffolk Nat. Soc. 39 (2003)


Suffolk Natural History, Vol. 39

October 2002. I will certainly investigate further having not seen them before in 17 years here. Rob Brown must be thanked at this point for supplying me with data from his River Stour headwaters survey, undertaken as part of his studies at Essex University. This produced a wealth of interesting species including not only signal, Pacifastacus lenuisculus, but also native crayfish, Austropotamobius pallipes. In addition to the mayflies mentioned above Rob found some less well recorded species such as Ephemera danica and also Habrophlebia fusca and Paraleptophlebia submarginata. Records of these species are always welcome but much further up my wanted list are Leptophlebia marginata and L. vespertina, each only recorded once in Suffolk. Several interesting caddis flies turned up in Rob’s survey including Hydropsyche contubernalis, which is a first record for the county and H. instabilis, which has only been recorded once. This will be an important addition to our lists and I will be looking to find specimens myself soon. Whilst on the subject of the Trichoptera or Caddis Flies it is worth noting that Agraylea multipunctata, one of the purse-cased Caddis, has been recorded more frequently during the last two seasons and Hydroptila species have been common during the last season particularly in the west of the county. It is unfortunate that the Hydroptilids cannot be identified reliably to species level from larvae at present. Rob also contributed many records from Minsmere, which is another area needing more recording time. As well as some interesting beetles there were several promising caddis sightings. Though many species were early instars and could not be fully identified I noted some families where old Suffolk records of rare species exist, from just that type of habitat. Aquatic Bugs have long held a particular fascination for me and I am pleased to report that during August 2001 the data set for the first national atlas of water bugs (Hemiptera - Heteroptera ) was finalised thanks to the heroic efforts of Thomas Huxley from Perth. The actual atlas is now in preparation. All Suffolk records were sent up to be part of the atlas. Having checked and collated all records I took the opportunity to put county distribution maps for all our Heteroptera species on the Freshwater Invertebrate Survey of Suffolk website. They are accessible at the address below and the maps have been updated regularly as new records have been made. For many seasons I have thought that the brackish water corroxid bug Sigara selecta might be found on the Suffolk coast. I am therefore pleased to say that Bernard Nau e-mailed me to report finding it together with S. stagnalis (as might be expected) at Shingle Street in August 2002. This is the first record for the species in 50 years. I should say that this pleasing news was tinged with slight annoyance; since the bug had eluded me at exactly the same spot only a few months earlier. Such are the vagaries of fieldwork. However I was able to return to a rain soaked, wind lashed Shingle Street in October 2002 and find them both still present in abundance. Bernard has also contributed a record for Micronecta minutissima from the River Stour near Flatford back in 1973. This is the only record for the species but with his comments on

Trans. Suffolk Nat. Soc. 39 (2003)



identification I shall be on the lookout for more. Finally he also reports that the large pondskater Aquarius paludum has arrived in Bedfordshire in large numbers, it will be worthwhile watching out to see if it’s increasing range may eventually spread into Suffolk. Another pondskater worthy of note is Gerris thoracicus. Only recorded three times before from the county I found it to be quite common at Reckford Bridge on the Minsmere River in September 2002. It also has the distinction of being the first species I’ve had confirmed electronically from e-mailed digital photographs to Thomas Huxley in Scotland. I remember, a few years ago now, putting out a plea for records of Nepa cinerea, Ranatra linearis and Ilyocoris cimicoides on the grounds that they were very easy to identify and anybody could have a go at recording them. Whilst many records of Nepa and Ilyocoris continue to be made each season only two records of Ranatra were made in the last two years. Does this imply a reduction in numbers? If you do locate the species, then please let me know. Distribution maps and identification photographs are available on my web site to aid anyone who wishes to find them. Finally, an easier request. I mentioned above that the Brett is a particularly clean and healthy riverine habitat. I am sure that some members out there are already complaining that their local stream, river or pond is just as good. So don’t sit and moan in silence! I would really appreciate being told about potential sites to survey, especially if you are a landowner with a normally inaccessible or hidden wetland area. Even if you can’t identify the invertebrates you see wriggling about in the water you can pass on the most important data, local knowledge. Let me know of your favourite sites via the addresses below. Adrian Chalkley, Freshwater Invertebrate Recorder 37 Brook Hall Road, Boxford, Sudbury, Suffolk CO10 5HS E-mail Phone 01787 210140 The Freshwater Invertebrate Survey of Suffolk website can be found at: or White Admiral e-zine, now with 13 editions on line, is part of the same site:

Trans. Suffolk Nat. Soc. 39 (2003)

Freshwater Invertebrate Recorder’s Annual Report 2002  

Adrian Chalkley

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