Worcestershire Record No. 16 April 2004 pp. 10-11

THE NOBLE CHAFER GNORIMUS NOBILIS. RECORDS NEEDED!

Harry Green

Noble Chafer Gnorimus nobilis. Photo Matt Smith ©.
Note the small scutellum (between the elytra, adjacent to the thorax) and the sculptured appearance of the elytra compared with the Rose Chafer right.
Rose Chafer Cetonia aurata. Photo Roger Key.
Note the large scutellum and shiny appearance compared with the Noble Chafer left.

We have been asking for records of this spectacular beetle for several years, and we are asking again! Please keep your eyes open for large green beetles flying on hot days!

A picture post card which gives a good idea of the appearance of the beetle is enclosed with this edition of Worcestershire Record. It also shows the somewhat similar Rose Chafer Cetonia aurata, which is now quite scarce in Worcestershire although it was once much commoner than Noble Chafer. The card asks for records to be sent to Peoples Trust for Endangered Species (PTES) and this can be done, but it would be helpful if any sightings could be reported to the author as quickly as possible. All the records will in any case be consolidated into a national record.

Obtaining new records are now even more important because Worcestershire is becoming recognised as a nationally important stronghold for the species, akin to N and W Gloucestershire. New sites were discovered in 2003 and early 2004 near Evesham, and south of the Wyre Forest near Menith Wood. Old and decaying orchards are the places where frass, larvae or beetle fragments have been found in decaying trees, and the trees used are plums, apples and cherries. Sightings of the adult beetles are rare (as can be appreciated from the life history outlined below) because they are often only on the wing for a short season – very hot days in July offer the best chance of sightings when the flying beetles visit flowers such as hogweed and meadow sweet. However, the presence of Noble Chafers can be detected by searching for their frass in decaying fruit trees, although great care should be taken not to excavate and kill the larvae that burrow their way through the red-rot wood mould. The pictures show the appearance of the frass. If anyone finds granular material in a hollow tree which looks like this please contact Harry Green on 01386 710377 right away!

The study of Noble Chafers is co-ordinated by Peoples Trust for Endangered Species (PTES) as lead partners for the national Biodiversity Action Plan (BAP), charged with ensuring the survival of the species. The BAP steering group includes eminent consultant field entomologists Keith Alexander, Matt Smith and Jonathon Cooter, persons from EN (Roger Key, Peter Holmes), WWT (Harry Green and Steve Bloomfield), from Gloucestershire and Herefordshire Trusts, DEFRA, and other experts. Funding from EN and elsewhere is supporting specialist field work. New parts of Worcestershire, Gloucestershire and Herefordshire will be surveyed in 2004.

Worcestershire Wildlife Trust Newsletter – Worcestershire Wildlife News
What follows is a slightly modified version of the article in the April 2004 issue  © 

The Noble Chafer is a handsome, somewhat globular, greenish, iridescent rare beetle about the size of the first joint of a man’s forefinger. Its larvae live in rotting wood in fruit trees. Five years ago it was thought to be threatened with extermination and a national Biodiversity Action Plan (BAP) was written. A group of entomologists and other experts was convened to study its habits and to undertake suitable conservation activities. The BAP Group is led by the Peoples Trust for Endangered Species (PTES) and assisted by funding from English Nature. The following notes are based on the work of several entomologists. The Trust has of course been involved with this work both locally and nationally.

Study of old and new records revealed two main areas of occurrence for the beetle, one in Kent and the other around North Gloucestershire, Worcestershire and Herefordshire. The outstanding feature-in-common between these areas is fruit growing. One hundred years ago they containing thousands of acres of cherry, apple and plum orchards, and although many have been cleared in recent years, many with old trees still survive.

Their importance (in the context of this note) is that historically, since the last ice age, Noble chafers were probably at first insects of birch and willow trees, then of oak, and then of fruit trees. There are no modern records of them using any wild growing trees of any species, all are in orchards with old decaying trees.

For breeding the beetles prefer mature plum, apple and cherry trees, with decaying wood beneath the bark or in the centre of the trunk. Eggs are usually laid in areas of red-rot wood-mould formed by the action of fungi. The larvae consume this lignin-rich food and produce characteristic faecal pellets – frass – which may come so abundant in trees used over a long period that it accumulated like fine gravel. The pellets are at first pale in colour, but darken with age, and appear to remain inside trees for several years after they are formed, if they remain dry and sheltered from rain. Pellets can often be seen by looking through holes formed when a branch stub or part of the trunk rots away and they accumulate in the hollow branch or trunk, and sometimes in rot beneath bark. Spiral bands of rotting wood arising from branch pruning may also be used. The pellets provide good evidence that larvae have been living in a tree, and can be substantiated by seeing larvae or parts of dead beetles. The larvae pass through several growth stages and eventually pupate after two or three years. The beetles emerge in summer. If conditions and food supply within a tree remain good the adult beetles may never leave it. They mate within the tree and lay eggs without ever flying. When they do emerge and fly it is usually in very hot days in July and they visit flowers such as hogweed and meadow sweet for nectar.

The first research in Worcestershire discovered Noble Chafers using old plum orchards, mainly in the Vale of Evesham but also elsewhere. Further searches found them in orchards near Wyre Forest, and in 2003 good populations were found in apple, cherry and plum orchards south from Wyre Forest. They have been seen flying in the Trust’s Tiddesley Wood reserve and probably breed in nearby orchards.

Researches driven by PTES are continuing but it now seems likely that a good population of this rare beetle inhabits much of south and west Worcestershire and neighbouring counties. Because of their very close association with old orchards there are considerable concerns for their survival. Most of many orchards present fifty years ago in the Vale of Evesham, and many of the old cherry orchards of west Worcestershire have gone, so it is now important that those that remain are conserved, managed to keep the old trees and new trees added to provide for the future. In addition to Noble Chafer many of these contain other interesting and scarce insects associated with decaying wood.

There is still much to learn about the distribution of these beetles in Worcestershire and we should very much like your help in finding them. Please look out for them visiting big pale showy flowers such as dog roses, meadow sweet, elder and hogweed during hot summer days. If you do see them please contact Harry Green or Steve Bloomfield through the Trust office as soon as possible. If you have an old orchard with suitable trees please also let us know and we will try to visit you and look for evidence of noble chafers.

(Since this article was published we have received two reports of likely sites and sightings near Tenbury Wells).

Noble Chafer frass in plum tree rot hole. The hole is exactly 4 cm internal diameter. Photo Harry Green ©    Noble Chafer frass and fragement of decaying wood in plum tree rot hole.Photo Harry Green ©   
Noble Chafer frass in plum tree rot hole.  Photo Harry Green ©    Noble Chafer larvae lying on a bed of frass in decaying cherry tree. Photo Matt Smith © 
Noble Chafer frass in plum tree rot hole.  Photo Harry Green ©    Noble Chafer larvae and  frass in decaying cherry tree. Photo Matt Smith ©

 

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