DERC Newsletter

No. 50 Autumn / Winter 2003

• Rare Plant Register
• Workshop feedback
• Distinctive Insects

Thank You

First a "thank you" to those recorders who have already sent in their records for this year. I am sure there is still much more to come. Hand-written, completed forms or emailed records are all welcome. The deadline for contributions is the end of January 2004.

We have been looking at ways to provide better feedback for recorders and, luckily, John Hunnisett has offered to co-ordinate an additional web-page for the DERC website, Dorset Firsts – first recording of a species in the county, complete with pictures where possible. So if you have seen anything unusual we would be keen to know more.

There has also been an exciting new development for the Marine database. We now have access to over 3,000 algae records for Dorset previously held by the Biological Records Centre in Huntingdon. These records were originally gathered from a number of sources for the publication of an algae distribution atlas in 1985. Records continue to be added to make this one of the most comprehensive datasets for marine algae in the UK. The Dorset records will be imported into the Dorset database over the coming months.

As usual our newsletter includes an update on current projects plus an article on red and black insects which I hope will provide you with some inspiration for recording next year.

Carolyn Steele (Record Centre Manager)

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Rare Plant Register

Eyebright (Euphrasia anglica) Photo: Bryan Edwards

Steady progress has been made on re-surveying sites for species where there is no record since 1990. Success has been mixed with only 41% of the 122 sites visited producing a positive result. However, this highlights the need for the Rare Plant Register and for regular monitoring. Some species such as Sea Pea (Lathyrus japonicus) and Narrow-leaved Lungwort (Pulmonaria longifolia) were predictably refound as the habitat in which they are found is fairly stable. Other species have not faired so well.

Of the 14 sites for Marsh Lousewort (Pedicularis palustris) visited it was only refound in three. This represents a real and significant decline for this species, which is an annual and requires open habitats and prefers grazing.

Other species that have shown a worrying decline include Marsh Helleborine (Epipactis palustris), Pond Water-crowfoot (Ranunculus peltatus) and Field Fleawort (Tephroseris integrifolius).

Thank you to all those recorders who have helped with the project over the summer.

David Pearman and Bryan Edwards

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Workshop Feedback

The small mammal day at Kingcombe Photo: John Stobart (English Nature)

A big thank you to all the organisers and participants of the DERC summer workshops. Once again they were a huge success with over 50 people attending. We held two mammal workshops – an evening at Kingtson Maurward armed with bat detectors, and a dormice and small mammal day at Kingcombe. These were particularly well attended both by recorders and by the furry friends we were there to see!

Dormouse on a branch Photo: John Stobart (English Nature)

In June, Bryan Edwards gave a valuable NVC acid grassland workshop at Corfe, and despite the ceaseless rain in the morning everyone returned from lunch in high spirits and eager to glean more of Bryan’s botanical expertise. There was a lot to see on the invertebrates day at Melbury Park. With a week of warm evenings the moth trap was full to the brim and among the captives was the stunning and rare Orange moth (Angerona prunaria) making Melbury the third Dorset site for this species.

For those that missed out there will be more next year. We hope to see you there!

Maria Pegoraro

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Distinctive Insects

Cercopsis vulnerata Photo: Ian Cross

Whilst a majority of insects cannot be identified without prior knowledge of the family there are some which are so characteristic as to become immediately recognisable, the 7 spot ladybird being one such creature. There are four other red and black insects of interest to look out for next year, two fairly common and two rare, which although not as common as the ladybird can be easily identified in the field. The first is the froghopper Cercopis vulnerata which can be found in lush vegetation along roadsides and ditches usually bordering woods. It is about 10mm long with a shiny black head and red and black wingcases that are held tent like over its abdomen. It is usually found between April and July. The larvae are gregarious and live underground in a mass of solidified froth. DERC has 58 records for this species scattered throughout Dorset but for such a distinctive insect this number could be easily increased. The easiest way of identification is to compare it with the photograph (left).

Corizus hyoscyamii Photo: Ian Cross

The second insect is not as common but nevertheless could turn up anywhere in Dorset including your garden. It is an heteropteran bug known as Corizus hyoscyamii (right). Whilst its name suggests an association with Hyoscyamus niger Henbane, in Dorset it has rarely been found on this plant. Again it is a red and black bug, in this case holding its wings flat against its abdomen. The main coloration is red but with two distinctive black circles on its forewing about halfway along. It also has a black collar just behind its neck. Again the best means of identification is to compare it with the photograph shown. It has been recorded from 19 sites in Dorset, 11 coastal and 8 inland. If found it would be of great interest to record the plant species on which it was seen, a photograph of both would be even better!

Pyrrhocoris apterus Photo: John Hunnisett

As I have already said these insects are distinctive, however, as usual there is a ‘but’. There is another species that can, at a casual glance be mistaken for C. hyoscyamii. It is a Southern European bug commonly known as the Fire Bug. Pyrrhocoris apterus (left). To date there has been only one siting in Dorset and very few for the rest of the country.

The most noticeable difference between the two insects is the very distinct black triangle in the centre of its body. (See photograph) Before records of this species can be accepted, either a clear photograph or the insect would need to be examined.

Eurydema dominulus Photo: Ian Cross

Finally it is possible that someone could be lucky enough to find the shieldbug Eurydema dominulus which was found in Dorset for the first time in 1997. This bug is about 7mm long and more robust than the previous insects, again with a very distinctive pattern of red and black patches. It is usually associated with crucifers and could be found from May onwards. Again the best means of identification is to compare it with the picture, and some means of proof would be required before a record would be accepted.

We had a good response from my last article on spiders - I hope even more of you will reply to this call for records.

John Hunnisett

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