Return to HRS home page Dipterists Forum
A Dipterists Forum recording scheme

Navigation
Home
Forum
Photo gallery
Maps
Checklist
Hoverfly Newsletter
Memberlist
User-groups
FAQ
Search

User
Username:

Password:

 Remember me



I forgot my password

Don't have an account yet?
You can register for FREE


Search

Advanced Search

Who is Online

In total there are 3 users online :: 0 Registered, 0 Hidden and 3 Guests

Registered Users: None

[ View complete list ]


Most users ever online was 305 on Mon Nov 18, 2019 11:39 am


Lejops vittatus

 
Post new topic   Reply to topic    Hoverfly Recording Scheme Forum Index -> The Species
View previous topic :: View next topic  
Author Message
stuart
Site Admin


Joined: 11 May 2005
Posts: 737
Location: Peterborough, UK

PostPosted: Sat May 28, 2005 5:39 pm    Post subject: Lejops vittatus Reply with quote

Lejops vittatus (Meigen, 1822)

NomenclatureIdentification ease/difficulty: 2

StatusSources of information
Back to top
View user's profile Send private message Send e-mail
stuart
Site Admin


Joined: 11 May 2005
Posts: 737
Location: Peterborough, UK

PostPosted: Sun May 29, 2005 8:41 am    Post subject: Species account from the Provisional atlas Reply with quote

Species account from Provisional atlas of British hoverflies, Ball & Morris, 2000.

Lejops vittatus (Meigen, 1822) Helophilus vittatus Meigen in Coe (1953)

Biology: Larvae aquatic. Speight (1998) quotes a German description of the development: Eggs are apparently laid on stems and leaves of emergent plants. When larvae hatch, they remain at the water surface amongst floating plants until the last instar when they move into submerged organic ooze at the bottom of the water body. In Britain, it is associated with stands of Scirpus maritimus in grazing marsh ditches, from which adults can be swept. Adult females have been found feeding on the pollen of this plant (Stubbs, 1996)

Distribution: A very local species of coastal grazing marshes, with most records from the Thames Marshes. There are also recent records from Norfolk (Halvergate Marshes), Kent (Romney Marsh), Sussex (Pevensey and Lewes Levels), Somerset (Somerset Levels and Bridgewater Bay) and Glamorgan (Gwent Levels). It is not infrequent where it occurs. Apparently not confined to coastal marshes elsewhere in Europe and there is a seemingly genuine inland record: an old, undated specimen in the Natural History Museum collection from Felden, Hertfordshire collected by A.Piffard who lived in Felden and died in 1909
Back to top
View user's profile Send private message Send e-mail
stuart
Site Admin


Joined: 11 May 2005
Posts: 737
Location: Peterborough, UK

PostPosted: Sun May 29, 2005 9:08 am    Post subject: Data sheet from Insect Red Data Book, Shirt, 1987 Reply with quote

Datasheet from the Insect Red Data Book, Shirt (1989).

Lejops vittata (Meigen, 1822) VULNERABLE

Identification: Stubbs & Falk (1983), pp. 99 and 197, pl. 12:5.

Distribution: Mainly coastal; the Thames estuary (Kent and Essex), the south-eastern Channel coast (East Sussex and Kent) and in Norfolk and Somerset.

Habitat and ecology: Mainly coastal grazing marshes, associated with mildly brackish ditches (especially those with sea blub-rush Scirpus maritimus intermixed with freshwater plants). Some sites are several miles from the coast where sea club-rush survies from earlier times of more saline conditions. The larvae are unknown but are predictably of the rat-tailed maggot type adapted to aquatic conditions.

Status: In the past it was regarded as a rarity, apart from in the `Thames Marshes` where it was locally frequent. It is now much more localised and rare in the Thames estuary, but it has recently been found in small areas in some additional counties. At only one site, in Somerset, has it been seen in reasonable numbers, and then only along one short length of dyke (1983, A.P. Foster).Conservation: Present on at least two SSSIs.Threats: The extensive conversion of coastal grazing marshes to intensive cereal farming has destroyed a great deal of habitat and threatens most of the known sites. Major deepening and clearance of ditches, often with pump drainage, is associated with the eutrophication of ditches from fertiliser run-off. The Thames Barrage has resulted in extensive modification of flood embankments and ditches for many miles of coast. Saline influence is likely to weaken on most remaining sites. Nearly all sites are in areas suffering conservation problems, such as the Somerset Levels.

Author: A.E. Stubbs.
Back to top
View user's profile Send private message Send e-mail
stuart
Site Admin


Joined: 11 May 2005
Posts: 737
Location: Peterborough, UK

PostPosted: Sun May 29, 2005 9:08 am    Post subject: Data sheet from National Review of Diptera, Falk, 1991 Reply with quote

Datasheet from the Review of Scarce and Threatened Diptera, Falk (1991).

LEJOPS VITTATA (Meigen) VULNERABLE

DISTRIBUTION Scattered records from the coastal marshes of southern England from Somerset to Norfolk with most records from the Thames estuary, Sussex and Somerset. There is an old inland record from Hertfordshire but this seems very dubious.

HABITAT Coastal marshes. There seems to be a close association with Scirpus maritimus growing along ditches or in adjacent marsh, indicative of brackish conditions usually at the transition to freshwater where freshwater plants occur with the Scirpus. However, it can occur several miles from the sea on coastal levels where in the past saline influence was more direct.

ECOLOGY Larvae aquatic, probably living in the ditches or pools of coastal marshes. Adults recorded from May to September. Adults have been seen feeding on the pollen of Scripus maritimus and are well camoflaged on the flower heads.

STATUS Rare, though it has been found to be locally frequent in a small number of sites in North Kent, Sussex and Somerset with about a dozen known post 1960 sites. However the habitat required is diminishing.

THREAT The destruction of coastal marshes through drainage for agriculture and coastal development; complete or extensive clearance of marginal vegetation from water edges. Major deepening and clearance of ditches, often with pump drainage, is associated with the eutrophication of ditches from fertilizer run-off. The Thames Barrage has resulted in extensive modification of flood embankments and ditches for many miles of coast. Saline influence is likely to weaken on most remaining sites. Nearly all sites are in areas suffering conservation problems.

MANAGEMENT Maintain a high, stable water level and employ rotational ditch management where necessary on grazing levels and marshes to ensure all successional stages are present every year. In the long term it may be necessary to take measures to top up the salinity.
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    Hoverfly Recording Scheme Forum Index -> The Species All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group