Dichotomous table for gallers on Aesculus
by Hans Roskam
1a On leaves or on branches => 2
1b Inflorescence with abnormal felt-like pubescence. A. hippocastanum: Unidentified gall mite
2a On leaves => 3
2b Thicker branches with spindle- to club-shaped swellings, bearing Viscum album
3a Localised galls on leaf blade => 4
3b Leaves rolled downwards. A. hippocastanum, pavia: Aphis fabae
4a Lenticular gall on leaf underside. A. hippocastanum: Unidentified gall midge
4b Abnormal tufts of hairs on underside of vein axils; on upper side a corresponding arching. Hairs many-celled, long, weakly club-shaped. Aesculus spp: Aculus hippocastani
4c Rusting and abnormal hairiness of leaf blade. A. hippocastanum, glabra, neglecta: Shevtchenkella carinata