Essex gall report 2001-2002
There is some debate as to whether distortions caused by aphids are true galls; inflated leaves on
Mouse-eared Chickweed Cerastium fontanum caused by the feeding of Brachycolus cerastii were
found by Terri Tarpey at Birch Quarry (TL9219) in 2002. There are currently only three other
recent Essex records for this species.
Galled flowers of Bittersweet Solanum dulcamara found at Gravel Wood (TM1625) on 3 August
2002 contained larvae of the cecid Contarinia solani, apparently a new addition to the county list.
At the last Field Club social, Charles Watson exhibited a distorted specimen of Ganoderma
applanatum from Hatfield Forest. The distortions were recognised as galls of the platypezid fly
Agathomyia wankowiczii, recently added to the British list and again new to Essex.
At Harwich beach, galls of Eurytoma hyalipennis on Sand Couch Elytrigia juncea were found in
March 2001. This hymenopteran is apparently most abundant in areas where trampling of the host
plant occurs.
Amongst the cynipids, Ray Ruffell added Andricus quercusramuli to the records for TL9921 with
a Cotton-wool gall found at Friday Woods, Colchester. This elusive species turns up infrequently in
the County. The author has continued to monitor the spread of the Ram's-horn gall Andricus aries,
reported new to the county in 2000 (Bowdrey 2001). It has reached as far north as Great Oakley,
but efforts to find the galls in the north-western part of Essex and south Suffolk have so far proved
fruitless. Galls of this species were, however, common on epicormic oak shoots at Lingwood
Common (TL7705) on 19 July 2002.
At nearby Danbury Common (TL7804), galls of the spring generation of Neuroterus tricolor were
abundant on 15 June 2002. Some were on Pedunculate Oak Quercus robur seedlings only a few
centimetres tall. This species remains the scarcest of the genus Neuroterus in the county with only
two other 10km square records. Spangle galls of its alternate generation are found in late summer
on lammas leaves. Rearing produced only the inquiline Cynipid Synergus nervosus. Little work has
been done in Essex on the inquilines of Cynipid galls since the pioneering studies of the Field
Club's Joseph Ross in the 1940s.
Mites
Brian Ecott has been carrying out surveys in the under-recorded west of the county, in South Weald
Park, Hainault Forest and Roding Valley EWT reserve. At Hainault Forest in 2002, he made the
second UK record of Vasates quadripedes, which induces the Maple Bladder gall on the leaves of
the ornamental alien Silver Maple Acer saccharinum (Ecott 2002), also a new addition to the
Essex list. The mite induces red pustules on the upper surface of the leaves.
Leaf-edge galls on Spindle Euonymus europaeus caused by Eriophyes convolvens were found at
Hylands Park, new to TL60 (Mark Hanson).
Publications
The highlight of 2002 was the publication of the new and long-awaited British Plant Gall Keys,
published by the British Plant Gall Society in conjunction with the Field Studies Council in the
AIDGAP series. It comes highly recommended and is essential for anyone seriously recording
galls. The keys are available from FSC, Preston Montford, Shrewsbury, Shropshire SY4 1MW
(01743 852140) price £18 plus £3 p&p.
Essex Naturalist (New Series) 20 (2003)
41