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The galls are spherical and attached usually to the underside of the leaf
In the adult insect the radial cell is three times as long as wide and the first abcissa of the radius
is strongly curved.
Diplolepis nervosa (Curtis, 1838) lkm.sq. records: 47 Common
Host: Rosa spp. wild rose
Part galled: leaf
The species appears to be widespread in the county, and was recorded by Niblett (1957) from
Epping Forest. Fitch (1882) described it as generally distributed, but not common
The distinctive spiked-pea gall of D. nervosa resembles a small 'sputnik' being spherical and
bearing one or more stout spines. The colour varies from green, through yellowish to bright red.
Galls are usually situated on the underside of the leaf, although they occur commonly, though
less frequently, on the upper surface. There are. however, two forms of the gall, one with spines
and the other without. Spiked pea galls can confidently be identified as D. nervosa but smooth
ones cannot and it is necessary to breed out the adult to determine the species.
The adult insect has the anterior tibiae red, posterior tibiae black and the second abscissa of the
radius is sometimes weakly sinuate.
Diplolepis rosae (Linnaeus, 1758) lkm.sq. records: 241 Common Plate 15
Common name: Rose Bedeguar, Robin's Pincushion
Host: Rosa spp. wild rose
Part galled: bud
This species is common throughout the County and shows no particular habitat preference,
being found wherever wild roses grow. Fitch (1882) described it as very common. The County
distribution up to 1988 is given in Bowdrey (1988).
The large and colourful galls of D. rosae are probably the best known of all the non-oak Cynipid
galls. The galls are covered in branched filaments which are at first green, then bright red,
eventually fading to brown. Old galls may persist on the rose bush for several years. The
filaments are lost leaving the hard gall cells with their emergence holes visible. When only a few
eggs have been laid in a leaf bud a small robin's pincushion can develop on the leaf.
The adult wasp has the radial cell at least twice as long as broad and the second abcissa of the
radius is weakly curved The angle of the second abcissa forms a weak projection into the radial
cell.
Essex Naturalist (New Series) 16 (1999)