DERC Newsletter

No. 49 Spring / Summer 2003

• Dorset Rare Plant Register
• Summer workshops 2003
• Spiders in the home
• New finds in 2002...

Thank You

Thank you to everyone who has sent in their records from 2002. Some of the highlights are mentioned below. This year work begins in earnest on the Rare Plant Register, and there is a call from John Hunnisett for more bug records, so please continue to send your records in.

Before Christmas I attended a very interesting workshop which looked at some of the legal matters relating to biological data. At DERC we have always taken the view that people who send records in to us are doing so on the understanding that this information may be made available to others as and when appropriate, and that recorders have trusted DERC staff to make these judgements (with the aid of our management panel and other experts).

However, much of this meeting (which covered human rights, data protection and copyright issues) concerned active rather than passive agreement. Hence we are currently revising our data release and data exchange forms to cover some of the issues raised. We are also working on a document which will set out our data access policy and bring DERC in-line with guidance from the National Biodiversity Network.

The DERC website already outlines the possible users of data held at DERC, and this seems the ideal place to lodge a copy of the policy plus any similar documentation. In the meantime if you have any thoughts on the issue, I would be pleased to hear from you.

Carolyn Steele (Record Centre Manager)

Dorset Rare Plant Register

Early spider-orchids Photo: Bryan Edwards

During 2003 we hope to complete a register of all of Dorset’s rare plants, showing the sites recorded since 1990. Thanks to the records already held by DERC and the Botanical Society of the British Isles, including those from Dr Bowen, we have a fairly good base. However, we need more information and there are two major ways that people could help:

• Firstly, we now have a list of plants with no recent records. Please contact DERC for more details.
• Secondly, to all recorders, the following 10 species are rare in Britain but so relatively common in Dorset that most people do not bother specifically to record them.

We intend to publish distribution maps of these species in the Rare Plant Register, rather than detailed texts, but many species have big gaps for post 1990 records. The current distribution maps, showing recent records, are here but we need to fill in the gaps. Please help us by sending any records for these species directly to DERC (don’t wait for your end of year submission).

David Pearman

Top

DERC Summer Workshops

Please book in advance leaving a contact number. Alterations to the programme may be necessary, and places are limited. More details will be sent out nearer the time.

Acid Grassland NVC

at Corfe Common 
Thursday 5th June with Bryan Edwards (£20)

Invertebrates Day

at Melbury Park
Friday June 27th with John Hunnisett and Phil Sterling (£5)

Bat Evening

at Kingston Maurward College 
Wednesday 16th July at 7 pm, with John Stobart (English Nature) and Imogen Davenport (DWT) (£5)

Dormice & Small Mammals

at The Barn, Kingcombe Centre 
Saturday 13th September with John Stobart (EN) and Sue Eden (£5)

Top

Spiders in the home

Pholcus phalangiodes Drawing: Robin Walls

Scytodes thoracica Drawing: Robin Wall

It’s a well-known fact that we share our houses with spiders. The so called House Spider Tegenaria saeva is regularly seen in autumn when running at high speed across the floor or perhaps when it is stuck in the bath, but others are not so obtrusive. There are two in particular that we would like to hear about, if you have them in your house.

Pholcus phalangioides is a spider that weaves a loose web in the corners of rooms. It is unmistakable in that it has very long legs and a cylindrical body about 10 mm long, but the most obvious characteristic is its habit of shaking and whirling its body at high speed when approached. It is possibly quite common in houses in southern England but vastly under-recorded.

The second is a much rarer spider that captures its prey by spitting a mixture of glue and poison at them. Scytodes thoracica is a much smaller spider, about 6 mm long but its markings and shape are very characteristic (see sketch). The only Dorset records for the latter species come from homes of arachnologists, surely this is too much of a coincidence.

John Hunnisett.

Top

New finds in 2002...

Hawthorn shield bug Photo: Kevin Cook

Dorset lays claim to having records for 471 of the 656 species of spider at present on the British list. Therefore finding a new species in Dorset is an unusual event. In June of last year Ian Pembroke swept a Salticid (Jumping Spider) from ground covering ivy on the east side of Portland. He identified it as Bianor aurocintus, a spider that has mainly been recorded from the south-eastern part of England. This record now constitutes the most south-westerly location for this spider.

Whilst carrying out a survey of chalk downland in Dorset, two species of Hemiptera worthy of note have been found. The plant hopper Ribautodelphax imitans was found by suction trapping on the southern slopes of Bincombe Hill in August. This record constitutes the fifth location in the British Isles, the others being in Sussex, Devon and Portland (Dorset).

A second site in Dorset has been found for the RDB 3 mirid bug Hallodapus montandoni. It was discovered whilst surveying one of the sparsely covered slopes of Maiden Castle. The other location in Dorset is Hod Hill.

...and plans for 2003

Unlike some of the more popular insects, there has never been a comprehensive review of the Heteroptera of Dorset, a situation that hopefully will be dealt with in the near future. The Heteroptera have mouthparts adapted into a syringe-like tube for sucking sap or blood. Some of their more common names are shield bugs, pond skaters and water boatmen. We would like to produce a booklet on Heteroptera but they have been very under-recorded in Dorset. If anyone has Heteroptera records not submitted to DERC or is interested in the study of this group of insects we would like to hear from you.

John Hunnisett

Top