Homonotus sanguinolentus is a predator of spiders of the clubionid genus Cheiracantheum. These spiders construct conspicuous retreats in a number of aerial locations, including grass flower heads and heather inflorescences. The wasp enters the egg-laying retreat of gravid female spiders and lays an egg on the front of the spider's abdomen. The spider remains alive in the retreat whilst the wasp larva feeds on its body fluids. After about 10 days the wasp larva kills the spider and consumes the remains. A greyish cocoon is spun up inside the retreat and the prepupa overwinters inside this.
This spider-hunting wasp has always been erratically and rarely found. There are eight records from lowland heathland in Dorset, Hampshire and Surrey, spanning the years 1900 to 1962. Since then the only record is of a single male taken on Cranes Moor in the New Forest in 1990. It is widespread, but rarely found, throughout southern and central Europe, but is highly thermophilous in the northern part of its range.
In Great Britain this species is classified as Endangered.
Current factors causing loss or decline
Loss of southern heathland, especially grass-heath.
Scrub and bracken development.
Most of the localities where this species has been recorded are SSSIs. The New Forest is a proposed SAC.
This species is the subject of an NE Pre-Recovery Programme.
Action plan objectives and targets
Maintain populations at all known sites.
Enhance the population size at all known sites by 2010.
Restore populations to suitable sites to maintain 10 viable populations within the historic range by 2010.
Proposed actions with lead agencies
Policy and legislation
Where appropriate, include the requirements of the species when preparing or revising prescriptions for agri-environment schemes. (ACTION: NE, MAFF)
Site safeguard and management
Where possible, ensure that all occupied and nearby potential habitat is appropriately managed by 2008, for example through agri-environment scheme management agreements. (ACTION: NE, MAFF)
Ensure that the habitat requirements of Homonotus sanguinolentus are taken into account in relevant development policies, plans and proposals. (ACTION: NE, LAs)
Ensure that this species is included in site management documents for all relevant SSSIs. (ACTION: NE)
Consider notifying sites supporting viable populations of Homonotus sanguinolentus as SSSIs, where this is necessary to secure their long-term protection and appropriate management. (ACTION: NE)
Species management and protection
If necessary to maintain 10 viable populations, undertake habitat restoration and/or re-introductions at suitable former or potential sites. (ACTION: NE)
Advise landowners and managers of the presence of the species and the importance of beneficial management for its conservation. (ACTION: NE)
Future Research and Monitoring
Undertake surveys to determine the status of the wasp by 2005. (ACTION: NE)
Promote ecological research to establish the habitat requirements of this species, the factors limiting breeding success at existing sites, and its dispersal ability. (ACTION: NE)
Establish a regular monitoring programme for the species. (ACTION: NE)
Pass information gathered during survey and monitoring of this species to a central database for incorporation into national and international databases. (ACTION: NE)
Communications and Publicity
Promote opportunities for the appreciation of this species and the conservation issues associated with its habitat. This should be achieved through articles within appropriate journals, as well as by a publicity leaflet. (ACTION: NE)
Links with other action plans
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume IV: Invertebrates (March 1999, Tranche 2, Vol IV, p249)