Worcestershire Record No. 25 November 2008 p. 10

DRAGONFLY ROUNDUP FOR 2008

Mike Averill

Like the previous year, 2008 started the dragonfly season promisingly with a warm spell at the start of May which encouraged the early emergence of species like Large Red Damselfly Pyrrhosoma nymphula and the Club-tailed Dragonfly Gomphus vulgatissimus. After eight years of poor emergence rates the Club-tailed Dragonfly seems to have recovered its status as numbers were the highest since 2000.

Attempts to collect the exuviae (cast larval cases) of the Scarce Chaser Libellula fulva were made easy by good emergence numbers at Eckington. This was part of a national study to attempt to assess where populations of this range-expanding species originally came from. DNA analysis can now be done from the tracheal tubes of exuviae, making this a non-invasive test compared to taking the legs of live specimens. This exercise will be carried out again next year for this species as well as the Club-tailed Dragonfly. If anyone would like to help let me know.

Unfortunately July, August and early September experienced long spells of cloudy wet weather which made sure the lawns didnít go brown but was not good for planning field outings. The wet weather made the gravel pits at Ryall full of deep water and therefore not so suitable for the Small Red-eyed Damselfly Erythromma viridulum, however a surprise sighting of a single male of this species at Broadheath made sure it was, once again, recorded in the county.

Despite the wet weather it was business as usual for many species with the Beautiful Demoiselle Calopteryx virgo; Ruddy Darter Sympetrum sanguineum and Southern Hawker Aeshna cyanea showing well. One species that provided a surprise was a single female Black Darter Sympetrum danae at Hartlebury Common bog. This species has only been seen at about seven locations before and not for about five years so it was good to see it for the first time at a location which would have once had the ideal habitat. Hartlebury Bog has been drying out, off and on, for the last fifty years and yet the last two years have been as wet as it must have been in its heyday. Realistically this is probably only a temporary wet phase made possible by the wet summers of the last two years. The Common should hold populations of typical lowland heath dragonflies like Common Hawker Aeshna juncea sadly not seen since the 1950ís; the Black Darter; the Emerald Damselfly Lestes sponsa and the Four-spotted Chaser Libellula quadrimaculata. The Four-spotted Chaser was actually seen emerging this year at the bog, which is another encouraging sign for the Common if only permanent water can be guaranteed.

2009 will be the second of a five year re-survey programme culminating in the publication of a new dragonfly atlas. I hope to have the latest maps available for the next newsletter when you can see where the gaps are and perhaps agree to cover a specific square near you.

WBRC Home Worcs Record Listing by Issue Worcs Record Listing by Subject