Apart from dragonflies, in general Herefordshire’s ponds have been poorly studied for invertebrates. For example to date only 156 species of water beetles have been found within Herefordshire (of which about 120 are associated with still water habitats) a relatively low number in comparison with the 250 species of water beetle recorded within Britain and Ireland.
The exception to this rule is Moccas Park National Nature Reserve with its associated water bodies where remarkably over 100 species of water beetles have been recorded over a 30 year period. Notable examples include Graphoderus cinereus which is listed as Red Data Book 3. The Lawn Pool at Moccas Park also supports the nationally scarce Medicinal Leech (Hirudo medicinalis) which is specially protected under the Wildlife & Countryside Act and also listed as Red Data Book 3.
At the Herefordshire Wildlife Trust Sturts reserve at Letton in the Wye Valley, the Mud Snail (Lymaena glabra) a Red Data Book 2 species was recorded in April 2003. It was found within the ditches and shallow ponds and typically was found in associated with the local Moss Bladder Snail (Aplexa hypnorum) and the Button Ram’s-horn (Anisus leucostoma). The latter species is known from 2 other sites within the county.
There are few records for aquatic bugs within Herefordshire, however, it has been interesting to observe how many ponds support all 3 species of the commoner backswimmers: the Common Backswimmer (Notonecta glauca), the Spotted Backswimmer (Notonecta maculate) and the Black Backswimmer (Notonecta obliqua). The latter species is generally found in upland habitats, but turns up frequently in ponds on the Devonian Sandstone.