NOTES ON SOME SUFFOLK GALL WASPS (HYMENOPTERA: CYNIPIDAE)

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NOTES ON SOME SUFFOLK GALL WASPS (HYMENOPTERA: CYNIPIDAE) JERRY BOWDREY Abstract Two species of herb cynipid gall wasps (Tribe Aylacini)) are added to the Suffolk list and significant new records of two additional species of Aylacini and one rose cynipid gall wasp (Tribe Diplolepidini) are presented.

Introduction The oak (Quercus spp.) galling Cynipidae have long been a popular subject of study amongst naturalists, not least because of the phenomenon of alternation of generations, whereby different generations of a single species look totally dissimilar, induce completely different galls, often on different plant organs and sometimes different oak species. By contrast, the cynipids that gall plants other than oaks, have less complex life cycles and are less well studied.

The present paper deals with several species belonging to this latter group.

(All records are the author’s own unless otherwise specified.)

Sources of earlier Suffolk records In Suffolk much of our knowledge of the Cynipidae is due to the work of Claude Morley. Between 1931 and 1932 Morley produced a synopsis of the British Cynipidae based on the characters of the adult insects (Morley, 1931– 1932). In these papers he mentioned several Suffolk localities for gall inducers. In 1932, Niblett & Burkhill and subsequently Niblett, Ross & Burkhill commenced a series of papers, in the same journal, on gall-causing Cynipidae in Britain (Niblett & Burkhill, 1932; Niblett, Ross & Burkhill, 1932). In their introduction they make the cautionary statement that ‘many species added to the British list in recent years appear to have escaped the notice of Mr Morley’.

In ascertaining the Suffolk status of the species mentioned below, I have taken account of both of the above papers and other published sources, as well as consulting the Morley collection (Accession no. R1952.22, & Fig. 1) held at Ipswich Museum.

Herb cynipids Tribe Aylacini The Aylacini comprise a group of primitive genera of gall wasps that induce structurally simple galls, principally in herbaceous plants (Csoka, Stone and Melika, 2005).

Aulacidea follioti Barbotin was added to the Suffolk list on the discovery of galls at Thorpeness (TM477606) on 11 September 1998 at the foot of a cliff, on Sonchus asper (L.) Hill (Bowdrey, 1993). This gall has since been found in the southernmost part of the county at Seafield Bay, near Stutton (TM1233), 16 August 2008 on the same host species, on a concrete block seawall. Adult females were successfully reared, confirming the initial identification (Fig. 2). Since its original discovery in Britain from Essex in 1993 (Bowdrey, 1994), the species has also been found in Kent (Jennings, 2008) and, together with the Suffolk examples, these are the only British records known so far. Whilst the host plant is common everywhere, only plants growing in proximity to the sea or on river estuaries seem to be galled by this wasp species.

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Figure 1. Part of Claude Morley’s Cynipidae collection.

Aulacidea pilosellae (Kieffer) was added to the Suffolk list on the discovery of galls found on Pilosella officinarum F.W. Schultz & Sch. Bip. at Dunwich cliff (TL4768) (Bowdrey, 1993).

Galls have since been found at Westleton churchyard (TM4369, 2 August 1995), Bawdsey cliffs (TM3540, 23 August 2008) and Shingle Street (TM3642, 19 September 2008). Two adult females were successfully reared from the Bawdsey galls, confirming the identification. Whilst the host plant

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Figure 2. Aulacidea follioti Barbotin female can form extensive patches in short turf, galls are usually present at very low density on the leaf midribs of the plant. Also known from Essex, Surrey and Yorkshire.

Aulacidea subterminalis Niblett NEW TO SUFFOLK Aulacidea subterminalis was described as new to science by Niblett (Niblett, 1946), reared from galls found in July 1943 at the ends of runners of Pilosella officinarum F.W. Schultz & Sch. Bip, in Surrey.

On 23 August 2008 whilst walking northwards along the coast from Bawdsey Ferry, large stands of Pilosella officinarum (Mouse-eared Hawkweed) were noticed growing on the cliff slopes (TM3540, & Plate 11).

This plant is host to two under-recorded species of cynipid gall wasp, Aulacidea pilosellae (see above) and A. subterminalis hitherto known in Britain only from a handful of sites in Surrey (Niblett, 1951, & Plates 11, 12).

It was noticed that the friable Red Crag soil had been readily scraped away by rabbits (Oryctolagus cuniculus) exposing the roots and runners of P. officinarum. Consequently, a search was carried out for galls of A. subterminalis on the runners and stem tips. Within minutes several putative galls had been found both on runners and shoot tips. Rooted runners from these plants were carefully removed, along with a small quantity of soil and transplanted later to clay flowerpots filled with a suitable light soil. Kept outdoors and regularly watered, the plants responded well to transplantation and grew on until winter when the leaves eventually died down. Following decomposition of the leaf blades, dry galls of A. pilosellae were found on the midribs, together with possible A. subterminalis galls on runners and shoot tips. The two gall types were carefully removed to separate glass tubes and brought indoors in spring 2009.

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In April two wasps were noticed in one of the tubes and a third emerged in the second tube, later in the same month. All were females.

The two species of Aulacidea associated with P. officinarum are very similar in appearance and are best distinguished by the shape of the scutellar fovae and proportions of the 3rd and 4th antennomeres, together with differences in the shape and sculpturing of the face (Eady & Quinlan, 1963).

On the basis of these features the first two wasps to emerge were clearly A. pilosellae whilst the third was A. subterminalis.

The example of A. subterminalis was sleeved on a potted Pilosella plant in an unheated greenhouse in an attempt to induce egg laying and gall formation.

(The presence of males is not essential for reproduction and where no males are present in a population this is by parthenogenesis, unmated females producing diploid daughters). At least one gall appears to have been initiated (August 2009).

Aulacidea tragopogonis (Thomson) New to east Suffolk (V.C.25) Aulacidea tragopogonis was added to the British list in 1930 (Bagnall & Harrison, 1930) on the discovery of galls on Tragopogon pratensis L. (Goat’s Beard), although the species was not included in Morley, (1931–1932). The species was previously known in West Suffolk (V.C. 26) from West Stow, (TL8073, 10 August 1987) (Hancy, 1998).

A single gall of this species was found on T. pratensis in rough, maritime grassland slightly inland from the shingle banks at Shingle Street (TM3642) on 19 September 2008.

The gall consists of an irregular, multilocular swelling at the junction of stem and root and can be hard to locate under the mat of dead plant material that accumulates in such habitats. In order not to jeopardise the survival of the species at the site, two of the many gall cells were carefully removed from the plant and kept in a cool room over winter. One female wasp emerged successfully in 2009 to confirm the identification.

From eastern England there are additional recent records for Essex and Cambridgeshire.

Phanacis centaureae Forster NEW TO SUFFOLK Species of the genus Phanacis gall stems of Compositae. Some produce cryptic galls which are visible only when the stem is split longitudinally or are indicated by emergence holes after eclosion of the adults.

P. centaureae was added to the British list by Bagnall (1917) from galls found in stems of Centaurea scabiosa L. in Northumberland. It has recently been recorded in eastern England from Essex, Norfolk, Cambridgeshire and Kent.

In Britain, Phanacis centaureae produces cryptic galls in the flowering stems of both Centaurea nigra L. and C. scabiosa L. There is some dispute as to whether any swelling of the stem is produced, Bagnall (1917) suggesting there is, but Niblett (1940) failed to find evidence for this. Certainly all the examples the present author has found on C. nigra show no distortion and the thickest stems are perhaps less likely to contain galls than those of more moderate breadth.

At the foot of Bawdsey cliffs TM3540 a stand of C. nigra was examined for galls by splitting stems and one stem revealed oval larval cells in the stem

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pith. These contained characteristic yellowish cynipid larvae and were lined by a polished nutritive layer.

A selection of stems comparable in diameter to the galled example were gathered and kept over winter in a flowerpot outdoors. In spring they were transferred to a container and brought indoors. In May a number of female P. centaureae emerged, only their minute emergence holes indicating the position of the galls.

In sexually reproducing colonies of P. centaureae, males are produced as normal, but are unusual amongst the Cynipidae in that their wings are vestigial. In some populations of herb gall wasps the male sex is extremely scarce or absent and this, at least in part, may be due to the action of a bacterium Wolbachia.

In neighbouring Essex, this species is found in both C. nigra and C. scabiosa, which is likely also to be the case in Suffolk. Also recorded in Cambridgeshire and Norfolk, it’s cryptic habits mean that it is unlikely to be encountered without a deliberate search.

The rose cynipid gall wasps, Tribe Diplolepidini Several species of the genus Diplolepis gall various native and occasionally introduced, species of Rosa. In Britain there are five, or possibly six, recognised Diplolepis species. D. centifoliae now being considered by most workers to be a form of D. nervosa (Pujade-Villar & Plantard, 2002 ) rather than a distinct species in its own right.

Diplolepis spinosissimae (Giraud) is a common species in the western part of Britain where its host Rosa spinosissima L. (=pimpinellifolia) is abundant, especially on dune systems. In Suffolk this host is scarce. However, D. spinosissimae can also gall roses of the canina group and both hosts have recently been recorded in the County.

Morley (1931) noted that he had found galls abundantly on the coast sandhills at Thorp [sic]- by –Aldeburgh on 10 July 1914 and that he found the galls on the Dunwich rose which he considered to be a colloquial name for the Burnet rose in Suffolk. Furthermore, he states that the galls are said to occur abroad on Rosa canina.

Simpson (1982) states that the Burnet rose is a native species found on old heaths and scrub, as well as being planted and naturalised. The so-called ‘Dunwich Rose’ is usually considered to be the Burnet rose which is indigenous in this area but the legend that it was brought by monks from Normandy suggests that it was probably a cultivated variety.

These Thorpe-by-Aldeburgh galls are in the Morley Collection at Ipswich Museum.

Standing above Diplolepis spinosissimae are three leaf galls and one stem gall plus an ungalled leaf, mounted on card. (Two other separate galls standing above this name are misidentified examples of D. rosae (L.)). Morley mentions that the adult gall wasp is rarely taken except by breeding, his sole wild female having been swept at Foxhall, near Ipswich, while collecting with Chitty on 27 May 1907. The only adult cynipid now standing above D. spinosissimae in the Morley collection is a female with no data and bearing a

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redetermination label of R. D. Eady, redetermined as either Aylax papaveris or A. minor, both of which induce galls in poppy (Papaver) capsules.

The spinosissimae galls differ from other Diplolepis leaf galls in that they protrude on both sides of the lamina and are not easily detached, as are those of D. eglanteriae (Hartig) (smooth pea gall) and D. nervosa (Curtis) (spiked pea gall).

In an effort to try and refind this species in the County, a list of possible host plant localities was obtained from Martin Sanford at SBRC. However, before it was possible to follow these up, presumed D. spinosissimae galls were found on Rosa canina agg. on the seawall at Brantham, near Keebles sluice (TM125333) on 14 July 2008. Unfortunately, the galls were insufficiently well developed and the small sample collected seemed unlikely to produce adult wasps. Consequently, a return visit to Seafield Bay near Stutton Mill (TM1233) on 16 August 2008 provided an opportunity to gather more developed galls which produced adult D. spinosissimae and the cynipid inquiline Periclistus spinosissimae Dettmer in 2009.

In the meantime, on 3 August 2008, numerous galls of D. spinosissimae were noticed on a planted Rosa spinosissima hedge around a garden opposite Westleton Common (TM4468). These were mainly leaf galls with a few on stems and one large and bizarre growth of the flower petals (Plate 13). Both the two species of cynipid mentioned above were reared from these galls in 2009.

Whether galls had originally been introduced on hedging plants or had colonised from wild roses is unclear. The colony was still present in July 2009 when Nigel Cuming visited.

In eastern England these galls have been recorded twice in Essex and also in Cambridgeshire and Norfolk (Manning, 1956) all on Rosa canina agg..

Acknowledgements I thank Martin Sanford for information on Rosa spinosissima localities, information on the status of the Dunwich Rose in Suffolk, and for access to the relevant section of the new, unpublished Suffolk Flora. Brian Spooner of RBG Kew for information on Rose nomenclature, Jose Pujade-Villar for literature, Valerie McAtear, Librarian of the Royal Entomological Society for bibliographical information and Nigel Cuming for rechecking the Westleton site this year.

References Bagnall, R. S. (1917). Phanacis centaureae Förster A cynipid (Hymenoptera) new to the British fauna. Entomologist’s Monthly Magazine 53: 275–276.

Bagnall, R. S. & Harrison, J. W. H. (1916). Talks about plant galls III. Gall wasps other than those affecting oaks. Vasculum 2(1): 9–12.

Bagnall, R. S. & Harrison, J. W. H. (1930). Preliminary records of two new British gall wasps affecting the Common Goat’s Beard (Tragopogon pratensis). Entomologist’s Monthly Magazine 66: 225–226.

Bowdrey, J. P. (1993). Three species of gall wasp (Hymenoptera, Cynipidae), new to Suffolk. Suffolk Natural History 29: 26–27.

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Bowdrey, J. P. (1994). A preliminary note on Aulacidea follioti Barbotin, 1972 (Hymenoptera, Cynipidae) a species new to Britain. Cecidology 9(2): 54.

Csoka, G., Stone, G. N. & Melika, G. (2005). Biology, ecology and evolution of gall-inducing Cynipidae. In Raman et al. Biology, ecology and evolution of gall-inducing arthropods. Plymouth, Science Publishers.

Eady, R. D. & Quinlan, J. (1963). Hymenoptera: Cynipoidea. London , Royal Entomological Society. (Handbooks for the Identification of British Insects 8(1a)).

Hancy, R. (1998). East Anglian area meeting at West Stow, 10th August, 1997. Cecidology 13(1): 9.

Jennings, M. T. (2008). Records of Aulacidea follioti Barbotin, 1972 (Hym. Cynipidae) and associated parasitoids from Kent with further records of the gall from Kent and Essex. Entomologist’s Monthly Magazine 144: 155–6.

Manning, S. A. (1956). Cynipidae (Hym.) from Norfolk. Entomologist’s Gazette 7(1): 41–47 Morley, C. (1931). A synopsis of the British hymenopterous family Cynipidae.

Entomologist LXIV: 150–153; 183–186; 206–210; 248–250.

Morley, C. (1932). A synopsis of the British hymenopterous family Cynipidae.

Entomologist LXV: 15–18; 38–40; 63–65; 89–91; 108–113; 130–133.

Niblett, M. (1940). British gall causing Cynipidae III. Entomologist LXXIII: 74–76.

Niblett, M. (1946). British gall causing Cynipidae V. Entomologist LXXIX: 264–266.

Niblett, M. (1951). The cynipid genus Aulacidea (Hymenoptera). London Naturalist 30: 8–10.

Niblett, M. & Burkhill, H. J. (1932). Gall causing Cynipidae in Britain I. Entomologist LXV, 193–197.

Niblett, M., Ross, J. & Burkhill, H. J. (1932). Gall causing Cynipidae in Britain II. Entomologist LXV: 232–235, 254–258, 274–275.

Pujade-Villar, J. & Plantard, O. (2002). About the validity of Diplolepis fructum (RĦbsaamen) and some new synonyms in Diplolepis nervosa (Curtis). In Melika, G. & Thuroczy, C. (Eds) Parasitic wasps, evolution, systematics and biological control. Systematic Parasitoid Laboratory.

Simpson, F. W. (1982). Simpson’s flora of Suffolk. Suffolk Naturalist’s Society, Ipswich.

Jerry Bowdrey Colchester and Ipswich Museum Service 14, Ryegate Road Colchester Essex CO1 1YG Email: jerry.bowdrey@colchester.gov.uk

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J. P. Bowdrey J. P. Bowdrey

Plate 11: Habitat and Gall (inset) of Aulacidea subterminalis Niblett (p. 37).

Plate 12: Old gall of A. subterminalis Niblett showing emergence holes (p.

37).

J. P. Bowdrey Plate 13: Petals of Rosa pimpinellifolia galled by Diplolepis spinosissimae (Giraud) (p. 40).