Ophrys insectifera

Taxonomy 

Ophrys insectifera L., Fly Orchid, is uncontroversial, even within the polymorphic Ophrys genus.

 

Synonyms:

  • O. muscifera Huds.
  • O. myodes Jacq.

There are very rare records of hybrids with O. apifera (N. Somerset and W. Sussex) and with O. sphegodes (E. Kent).

 

Chromosome No.: 2n = 36 (Stace 2010). 

Ophrys insectifera

Photograph by K.J. Walker

Identification 

Taller, more slender than the other members of the genus found in Britain and Ireland, with a distinctive blue patch across the narrow lip. The leaves differ from O. apifera in being shiny rather than waxy.

Distribution 

Widespread only in the south and south east of England, with well over half of the records and 60% of the recent records. Elsewhere it has been found in 40 hectads in E. Anglia (only two post 1987), in 70 hectads from Gloucs. northwards to Cumbria (c. 25 post 1987) and in 30 hectads in Ireland (with 16 of these post-1987). There are no records from Scotland, and only five from Wales.

European Temperate Element. It is widespread throughout central Europe, but with only scattered records from the Iberian Peninsular, the west Mediterranean, and southern Scandinavia east towards the Urals (Hultén & Fries 1985). As it is not as 'Mediterranean' in its climatic preference, its range extends further north than other Ophrys species (Sanford 1991).

Altitudinal range: 0-390 m (Helbeck Wood, Brough, Westmorland).

BSBI Hectad Map 

Click on the map to view full-size on the BSBI Maps Scheme website.

Status 

Origin: native.

Rarity: Scarce in Britain. Scarce in Ireland. Absent from Scotland and Northern Ireland.

Threat: Vulnerable (Cheffings & Farrell 2005). It is difficult to see a trend in the distribution. There were more records (about 90 additional 10km squares) in the New Atlas (Preston et al. 2002) than in Perring & Walters (1962), but an overall drop in hectads with recent records (c. 20) explains the reasons behind the listing as Vulnerable. However one would have to analyse each hectad to be able to say that the increase in overall recorded hectads was due to new records of old sites or new sites being found.

Conservation: added to the list of UK Biodiversity Action Plan priority species in 2007.

There is no clear pattern to the losses. Those in East Anglia and the Welsh Marches were largely before 1930, and those since are throughout the range. A study in 2004 covering Dorset, Hampshire and Sussex confirmed only small losses at a hectad level, but dramatic declines at tetrad, and even more at 1km level. A definitive map showing the number of tetrads per hectad would be a great help.

There is also no clear reason for the losses, though denser woodland, more overgrown woodland edges as well as losses to coniferisation and changes in management of quarries and verges are all reported as causes of loss. Some sites have been lost from drainage of fens. It is interesting that most of the other widespread woodland orchids, including Cephalanthera damasonium, Neottia nidus-avis and Platanthera chlorantha, are also listed on the Red List for the first time. Notes and possible resons for decline are in Edwards & Pearman (2004) and Sanford (1991). Furthermore other woodland edge plants, such as Campanula patula, Fallopia dumetorum and Melittis melissophylum have also dramatically declined, demonstrating that, in the writer’s view, this is one of the most threatened habitats in Britain.

There is anecdotal but no hard evidence for some decline in mainland Europe.

Ecology 

A shade-tolerant tuberous herb usually found on chalk and limestone soils, and, like many orchids, sporadic in its appearance. In the south of England it is usually found in open deciduous woodland and scrub, but also recorded from denser shade, especially in beech woods. In woodlands it may grow with other orchids, such as Cephalanthera damasonium, Neottia nidus-avis, Orchis mascula and Platanthera chlorantha, and is included in the NVC community W12. On wood edges it grows in CG communites.

More rarely, but increasingly further north it is found in calcareous grassland, chalk-pits, limestone pavement, disused railways, spoil heaps and, rarely, unstable coastal cliffs - reaching its northerly limit on limestone slopes scree? in Cumbria (Foley & Clarke 2005). Interestingly, Irish populations are confined to open calcareous flushes and fens (M13, M13b) very unlike its habitats in England. It still survives at least one similar site on Anglesey (Cors Bodeilio) where it grows on Schoenus tussocks within species-rich fen (I. Bonner, pers. comm.). See Roberts (1958) for details of this remarkable habitat.

 The Fly Orchid is not very slow growing but it does not easily colonise new sites. This may be partly due to low seed production (Sanford 1991). The flowers are visited by wasps but pollination is often haphazard, with as few as 20% of flowers with mature seed (Foley & Clarke 2005). Flowering often starts in May in the south, though this can continue till July, especially further north.The limitations of such a finely tuned pollination mechanism may become increased, as solitary wasps are also becoming scarce, due to habitat loss (Sanford 1991). 

Further Work 

It would be interesting to test the hypothesis that it has declined along woodland edges, by comparison with sites that were still managed in traditional ways, and it would be surprising if examples were not available.

Finer details on distribution are needed to evaluate real losses.

References 
  • Foley, M & Clarke, S. 2005. Orchids of the British Isles. Cheltenham, Griffon Press.
  • Halliday, G. 1997. A Flora of Cumbria. Centre for North-West Regional Studies, University of Lancaster.
  • Hultén, E. & Fries, M. 1986. Atlas of north European vascular plants: north of the Tropic of Cancer. 3 vols. Königstein: Koeltz Scientific Books.
  • Roberts, R.H. 1959. Notes on the fen habitat of Ophrys insectifera in Anglesey. Proceedings of the B.S.B.I. 3: 274-278.
  • Sanford, M. 1991. The orchids of Suffolk. Ipswich: Suffolk Naturalists’ Society.
Citation 
Pearman, D.A. (date accessed). Species account: Ophrys insectifera. Botanical Society of the British Isles, www.bsbi.org.uk.

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