Essex gall report 2000
JERRY BOWDREY
Fair View, Colchester Road, Thorpe-le-Soken, Essex CO16 0LB
Several interesting new records have been made during the past year, and these are detailed below
under the relevant Order of the gall inducers.
Hymenoptera: Cynipidae
Amongst the cynipids, the highl ight of the year was the discovery of. Andricus aries on Pedunculate
Oak Quercus robur in several sites across the county (see separate paper in this issue). There is
every chance that two other new arrivals to Britain, Andricus lucidus (the hedgehog gall) and
Aphelonyx cerricola, galling Turkey Oak Quercus cerris could also turn up in Essex.
Oak apple galls, induced by Biorhiza pallida, were unusually abundant this year, the pinkish galls
being visible from quite some distance away, and looking just like an out of season crop of apples.
The mild winter weather may have meant that more of the wingless asexual generation emerged
successfully from their root galls to oviposit in the oak buds during January and February.
Andricus quercusramuli, instigator of the cotton wool gall on oak, is sporadic in appearance, and
occurred at Little Clacton (TM1618) on 6.V.2000 (JPB).
On the inaugural field meeting of the Essex Invertebrate Forum, held at Harrison Sayer EWT reserve
(TL5544), galls of Liposthenus glechomae were found on Ground-ivy Glechoma hederacea, while
young Robin's pincushion galls of Diplolepis rosae caused a stir by looking superficially like the
galls of D. mayri, yet to be recorded in Essex and confined apparently to chalk areas. However,
close examination showed that the gall spines were branched, rather than straight as in D. mayri.
The second Invertebrate Forum meeting at Bedfords Park (TQ5193), in July, added several new
species to TQ59, including Andricus corruptrix, another comparative newcomer to the British Isles,
and A. testaceipes, a longer-term resident. A visit to Tiptree Heath (TL8814) in July revealed
encouraging numbers of Aulacidea hieracii galls on hawkweed Hieracium sp. Numbers had been
declining due to scrub encroachment, but the clearance work carried out recently has benefited this
species enormously.
A gall of Aulacidea follioti was found on Prickly Sow-thistle Sonchus asper at Colne Point nature
reserve (TM0913, 25.ix.2000, JPB), filling in the distributional gap between the site of its original
discovery at Fingringhoe Wick and populations in the Hamford Water area.
In November, prematurely fallen, stunted acorns from a specimen of Turner's Oak Quercus x turneri
were collected in Castle Park, Colchester (TL9925), and on examination were found to contain
Cynipid larvae. They belong to the genus Callirhytis, but identification to species may be some time
off as the adults may not emerge for several years.
Essex Naturalist (New Series) 18 (2001)
81