The Aquatic and semi-aquatic Heteroptera of Suffolk

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THE AQUATIC AND SEMI-AQUATIC HETEROPTERA OF SUFFOLK A D R I A N K. C H A L K L E Y To the general naturalist, casually observing the freshwater environment, the aquatic and semi-aquatic bugs are familiar insects. Skating across the surface, hanging f r o m it or jerkily swimming below, they are a common sight from the banks of rivers, streams, lakes or ponds. They are a relatively easy group to study due to the distinct ecological niche they occupy and yet no comprehensive description of the Suffolk fauna has ever been written, indeed very few individual records have been published. This survey was instigated with the aim of eventually providing such a description. In my previous articles, (SNS Trans. 30 & 32) I have presented some of my early records for the group. Here I give an interim account of the present knowledge of the distribution of species and outline the future direction of the survey which will, I hope, lead to the publication of an atlas for the county. Over 700 records have so far been entered onto the Computer database from 188 sites in Suffolk, some 200 more await entry. Data have been recorded on 46 species f r o m a total British list of 61. Of these, 37 are confirmed by modern records, a further 9 only exist as archive data. As well as my own records recent data have been collected from the National Rivers Authority and from a small number of individual recorders. Archive records have been obtained from the Field Studies Council at Fiatford Study Centre and from the records centre at Ipswich Museum.

Methods Düring this survey no overall attempt was made to obtain quantitative measurements by rigidly defining sampling time or volume. The general approach was to sample all accessible micro habitats at a site until it was judged that all the common species had been obtained from each. Freshwater habitats of all kinds were sampled using the following equipment and methods.

Hand-held, robust pond nets to sample in shallow water and from accessible areas of the bank.

Weed grabs and hooks to bring weed samples in from deep or inaccessible water or to drag mats of algae from the centre of a pond or lake.

Plankton nets to trawl through the water, grazing the substratum or the tops of weed banks to 'put up* bugs, particularly corroxids, which were then captured in the net.

Plankton nets and band held pond nets to trawl semi-submerged across the water surface, particularly along the edge of reed beds, and capture surface dwelling bugs.

Drift nets anchored to a stream bed to capture invertebrates washed from stones and the substratum in general.

Trans. Suffolk Nat. Soc. 34

(1998)


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The Aquatic and semi-aquatic Heteroptera of Suffolk by Suffolk Naturalists' Society - Issuu