|Galls on a leaf of Ribes alpinum|
- On redcurrant R. rubrum, galls caused by C. ribis which are yellow-green in colour.
- On R. alpinum, galls caused by C. korschelti which are pink, orange or reddish.
|Aphids on the underside of an R. alpinum leaf|
|Close-up of an aphid on the underside of an R. alpinum leaf|
|Siphons (or 'cornicles') at the rear of the aphid's abdomen|
Many galls are not well understood and minor discoveries like this can be made quite readily if care is taken to look, especially given that R. alpinum is not especially common in the UK and probably poorly studied. The lack of readily accessible/affordable identification guides (Blackman & Eastop's 2006 2-volume opus was needed for this species, but is not cheap) makes aphid study more difficult (plus some genera are taxonomically confusing and really require genetic analysis and/or research), but as I found, there are specialists who are ready to help and it's always worth asking. Now to let the authors of the gall key know what I've found, then check whether H. lactucae has been recorded in Hampshire before...
Blackman, R.L. & Eastop, V.F. (2006). Aphids on the World's Herbaceous Plants and Shrubs. (2 vols.). Wiley, Chichester.
Redfern, M. & Shirley, P. (2011). British Plant Galls (2nd ed.). FSC, Shrewsbury.