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These pages will look at the rarer Water Bugs in Northamptonshire, where they are found, why they are rare and what can or should be done to help improve or monitor the distribution.
The rarity is based on whether it has a rarity status of Nationally scarce, Nationally rare, endangered critically endangered or threatened. There are 8 species Micronecta griseola, Aquarius najas, Aquarius paludum, Microvelia pygmaea, Saldula pallipes, Saldula opacula, Saldula orthochila and Salda littoralis.
Micronecta griseola
Micronecta griseola
Nationally rare - Found only on the River Nene, Islip.
The most favoured habitat is a slow-moving river with some kind of hard substrate coated with a short ‘lawn’ of filamentous alga. Stray lumps of concrete, concrete bank lining, steel sheet piling, and bridge supports are all worth a look. (Het News Spring 2003)
The main threats for this is that there is only one colony identified in the River Nene. There should be similar habitat to this all the way down the Nene therefore if more extensive searches were undertaken then more colonies could be found. It is likely that this is currently extending its range with climate change.
Photo by: Marko Mutanen, University of Oulu
The most favoured habitat is a slow-moving river with some kind of hard substrate coated with a short ‘lawn’ of filamentous alga. Stray lumps of concrete, concrete bank lining, steel sheet piling, and bridge supports are all worth a look. (Het News Spring 2003)
The main threats for this is that there is only one colony identified in the River Nene. There should be similar habitat to this all the way down the Nene therefore if more extensive searches were undertaken then more colonies could be found. It is likely that this is currently extending its range with climate change.
Photo by: Marko Mutanen, University of Oulu
Aquarius najas
Aquarius najas
Nationally rare - Found only on the River Welland at Duddington
There are not too many habitats that would suite this in Northants as the River Nene is perhaps a little slow flowing, the River Welland skirts the northern Northants border and the Ouse skirts the Southern boarder.
It has not been found on the River Nene despite searching and maybe some concerted effort on the Welland and Ouse may create a few more records.
Aquarius paludum
Aquarius paludum
Nationally scarce - Found at Wilson’s Pit, Barnwell Country Park, Pitsford Reservoir, Islip Nine arches, Brampton Fisheries, Brackley St James Lake, Rushden Lakes, Stanwick Lakes.
This is a Southern species that is heading Northwards. There are no specific habitat preferences but like Lakes, Rivers and Streams. I have found it mainly on lakes and ponds in Cambs, Beds and Northants and it appears to like overhanging vegetation that it can shelter under and perhaps hunt species blown onto the water. Peter Kirkby has suggested that it replaces A. najas in slow rivers and lakes. It has very healthy populations at now 8 Northamptonshire sites and with the gravel extraction pits recently created and flooded it appears to have plenty of similar habitat to expand into.
The threats would be to open up the gravel pits too much and reduce marginal willows and vegetation. The depth of the water would usually keep these under control without management.
This is a Southern species that is heading Northwards. There are no specific habitat preferences but like Lakes, Rivers and Streams. I have found it mainly on lakes and ponds in Cambs, Beds and Northants and it appears to like overhanging vegetation that it can shelter under and perhaps hunt species blown onto the water. Peter Kirkby has suggested that it replaces A. najas in slow rivers and lakes. It has very healthy populations at now 8 Northamptonshire sites and with the gravel extraction pits recently created and flooded it appears to have plenty of similar habitat to expand into.
The threats would be to open up the gravel pits too much and reduce marginal willows and vegetation. The depth of the water would usually keep these under control without management.
Microvelia pygmaea
Microvelia pygmaea
Nationally scarce - Found in 10 sites.
This is a southern species that is extending Northwards and in the last 5 years from 2018 has expanded from zero to 10 sites in Northamptonshire. It’s habitat is overgrown/dense vegetation and litter at the edges of slow flowing water bodies e.g. ditches, ponds and lakes. It has a healthy population and plenty of similar habitat to expand into.
However uncontrolled scrub invasion from no management, loss of permanent standing water in ditches or pools and over clearance of bankside vegetation will erode habitat. Additionally and pesticide leakage from fields into ditches and pools could affect complete isolated populations.
Controlled management of vegetation to a third each year and surrounding fields to populations should be pasture rather than arable will minimise the effects on current colonies (PK,1992).
This is a southern species that is extending Northwards and in the last 5 years from 2018 has expanded from zero to 10 sites in Northamptonshire. It’s habitat is overgrown/dense vegetation and litter at the edges of slow flowing water bodies e.g. ditches, ponds and lakes. It has a healthy population and plenty of similar habitat to expand into.
However uncontrolled scrub invasion from no management, loss of permanent standing water in ditches or pools and over clearance of bankside vegetation will erode habitat. Additionally and pesticide leakage from fields into ditches and pools could affect complete isolated populations.
Controlled management of vegetation to a third each year and surrounding fields to populations should be pasture rather than arable will minimise the effects on current colonies (PK,1992).
Saldula opacula
Saldula opacula
Nationally Scarce. Found at Etton-Maxey Nature reserve.
This occurs in estuarine marshes on the east coast, the west coast and a few old records from Scotland. Very little is know about the inland records occurring in the fens around Cambs, Lincs and Northants.
However it appears to be expanding it’s range recently and as the fen habitat expands down the Nene Valley this could expand it’s range further into Northants.
This occurs in estuarine marshes on the east coast, the west coast and a few old records from Scotland. Very little is know about the inland records occurring in the fens around Cambs, Lincs and Northants.
However it appears to be expanding it’s range recently and as the fen habitat expands down the Nene Valley this could expand it’s range further into Northants.
Saldula pallipes
Saldula pallipes
Nationally scarce - Found in 6 sites.
This is an inland bug that is found in flooded gravel pits , pools and puddles on sandy clays and sandy gravels. Over the recent years with extensive gravel and clay extraction and the building of Reservoirs with extensive drawdown areas, this habitat has increased substansially and this species now getting established is also likely to expand across the county.
This is likely to be under recorded in Northants over the years due to the lack of bug recorders. It is not an easily identifiable species and could have been overlooked.
Photo from British bugs website
This is an inland bug that is found in flooded gravel pits , pools and puddles on sandy clays and sandy gravels. Over the recent years with extensive gravel and clay extraction and the building of Reservoirs with extensive drawdown areas, this habitat has increased substansially and this species now getting established is also likely to expand across the county.
This is likely to be under recorded in Northants over the years due to the lack of bug recorders. It is not an easily identifiable species and could have been overlooked.
Photo from British bugs website
Salda littoralis
Salda littoralis
Nationally scarce. Found at Etton-Maxey Nature Reserve
Northern, found in vegetated silty margins of rivers and lakes. It is mainly coastal brackish habitats in the south.
There are some records moving eastwards towards Cambs and Peterborough but likely to be looking for ancient brackish areas.
Photo from British bugs website
Northern, found in vegetated silty margins of rivers and lakes. It is mainly coastal brackish habitats in the south.
There are some records moving eastwards towards Cambs and Peterborough but likely to be looking for ancient brackish areas.
Photo from British bugs website
Saldula orthochila
Saldula orthochila
Nationally scarce. Found at Swaddywell Pit Nature Reserve.
This is found in sunny dry ground with moss and sparse vegetation, including sand dunes, waste lands and grassland.
These habitats are likely to be patchy in Northants.
Photo by: Rob Ryan
This is found in sunny dry ground with moss and sparse vegetation, including sand dunes, waste lands and grassland.
These habitats are likely to be patchy in Northants.
Photo by: Rob Ryan
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