|Water stick-insect Ranatra linearis|
|The raptorial front legs of Ranatra linearis|
Moving onto something smaller, at 9-12mm long (excluding legs and antennae), the Water-measurer (Hydrometra stagnorum) is another true bug common in much of lowland England and Wales (less so in Scotland and northern England) and is especially elongate, having the longest length-to-width ratio of any British insect - even the head is elongate, protruding well in front of the eyes which can be seen about half way between the antennae and front legs.
|The Water-measurer Hydrometra stagnorum|
Although both of these species are fairly common, this is not true of all our aquatic bugs - many (most) ponds in lowland Britain are polluted to some extent, especially by nutrients from our intensive agricultural system, and this has seriously impacted the biodiversity of pond ecosystems. With both point and diffuse sources being a problem, it can be difficult to ensure good ecologicsl water quality, but advice (on managing existing ponds or creating new ones) can be sought from organisations such as Pond Conservation. Garden pond ponds are a little different as few of us have enough room for the metres of shallow muddy margins that a really good pond needs, but some of the same advice applies and they are really important oases - and excellent fun to watch as the wildlife colonises it and does its thing!
|Naomi from Pond Conservation hard at work looking for aquatic invertebrates in a shallow pond in the New Forest.|
Denton, J. (2007). Water Bugs and Water Beetles of Surrey. Surrey Wildlife Trust, Woking. [Covers a good range of species; lots of useful info and excellent photos even if you're not in Surrey].
Fitter, R. & Manuel, R. (1994). Lakes, Rivers, Streams & Ponds of Britain & North-West Europe. HarperCollins, London. Also published in 1986 as Field Guide to the Freshwater Life of Britain and North-West Europe. [Both versions are out of print, but worth tracking either down online as they can be quite cheap.]
Huxley, T. (2003). Provisional Atlas of the British Aquatic Bugs (Hemiptera, Heteroptera). BRC, Huntingdon.
Savage, A.A. (1989). Adults of the British Aquatic Hemiptera Heteroptera: A Key with Ecological Notes. FBA, Ambleside. [The standard identification guide].